Energy › Renewable Energy, Sustainability and the Environment

Algal biology and biofuel production

Works Count: 96888

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Description

This cluster of papers focuses on the use of microalgae as a sustainable source for biofuels production, including biodiesel. It covers various aspects such as genome analysis, lipid accumulation, nutrient removal, and the use of photobioreactors for mass cultivation. The research also explores the potential commercial applications and the challenges in commercialization of algal biofuels.

Keywords

Biodiesel; Microalgae; Biofuels; Production; Harvesting; Genome Analysis; Nutrient Removal; Lipid Accumulation; Photobioreactors; Sustainable Industry

Algal Physiology and Biochemistry.

1975-03-01

Chase Van Baalen , W. P. D. Stewart

Algal culturing techniques

2005-10-01

Robert A. Andersen

1. Historical Review of Algal Culturing Techniques 2. Freshwater Culture Media 3. Marine Culture Media 4. Trace Metal Ion Buffers and Their Use in Culture Studies 5. Sterilization and Sterile … 1. Historical Review of Algal Culturing Techniques 2. Freshwater Culture Media 3. Marine Culture Media 4. Trace Metal Ion Buffers and Their Use in Culture Studies 5. Sterilization and Sterile Technique 6. Traditional Microalgae Isolation Techniques 7. Automated Isolation Techniques for Microalgae 8. Purification Methods for Microalgae 9. Isolation and Purification Techniques for Macroalgae 10. Perpetual Maintenance of Actively Metabolizing Microalgal Cultures 11. Long Term Macroalgal Culture Maintenance 12. Cryopreservation Methods for Maintaining Microalgal Cultures 13. Photobioreactors and Fermentors: The Light and Dark Sides of Growing Algae 14. Culturing Microalgae in Outdoor Ponds 15. Mariculture of Seaweeds 16. Counting Cells in Culture Using the Light Microscope 17. Phytoplankton Cell Counting by Flow Cytometry 18. Measuring Growth Rates in Microalgal Cultures 19. Using Cultures to Investigate the Physiological Ecology of Microalgae 20. Analysis of Algal Pigments by High-Performance Liquid Chromatography 21. Endogenous Rhythms and Daylength Effects in Macroalgal Development 22. Viral Contamination of Algal Cultures 23. Control of Sexual Reproduction in Algae in Culture 24. Microalgal Life Cycle Dynamics: Encystment and Excystment 25. Cultures as a Means of Protecting Biological Resources: Ex-situ Conservation of Threatened Algal Species

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Look Back at the U.S. Department of Energy's Aquatic Species Program: Biodiesel from Algae; Close-Out Report

1998-07-01

John Sheehan , Terri G. Dünahay , John R. Benemann +1 more

The Aquatic Species Program was a relatively small research effort intended to look at the use of aquatic plants as sources of energy. Its history dates back to 1978, but … The Aquatic Species Program was a relatively small research effort intended to look at the use of aquatic plants as sources of energy. Its history dates back to 1978, but much of the research from 1978 to 1982 focused on using algae to produce hydrogen. The program switched emphasis to other transportation fuels, particularly biodiesel, beginning in the early 1980's. This report summarizes the research activities carried out from 1980 to 1996, with an emphasis on algae for biodiesel production.

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Purification and properties of unicellular blue-green algae (order Chroococcales)

1971-06-01

Roger Y. Stanier , Riyo Kunisawa , M. Mandel +1 more

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SIMPLE CONDITIONS FOR GROWTH OF UNICELLULAR BLUE‐GREEN ALGAE ON PLATES1, 2

1968-03-01

Mary M. Allen

SUMMARY The efficiencies of plating of 2 cultures of unicellular blue‐green algae, 1 coccoid and 1 rod‐shaped, were studied systematically. Reproducible colony growth and accurate viable counts are dependent on … SUMMARY The efficiencies of plating of 2 cultures of unicellular blue‐green algae, 1 coccoid and 1 rod‐shaped, were studied systematically. Reproducible colony growth and accurate viable counts are dependent on the use of a low agar concentration, and on the sterilization of the agar separately from the mineral components of the medium.

Microalgae as biodiesel & biomass feedstocks: Review & analysis of the biochemistry, energetics & economics

2010-01-01

Peter Williams , Lieve M. L. Laurens

Following scrutiny of present biofuels, algae are seriously considered as feedstocks for next-generation biofuels production. Their high productivity and the associated high lipid yields make them attractive options. In this … Following scrutiny of present biofuels, algae are seriously considered as feedstocks for next-generation biofuels production. Their high productivity and the associated high lipid yields make them attractive options. In this review, we analyse a number aspects of large-scale lipid and overall algal biomass production from a biochemical and energetic standpoint. We illustrate that the maximum conversion efficiency of total solar energy into primary photosynthetic organic products falls in the region of 10%. Biomass biochemical composition further conditions this yield: 30 and 50% of the primary product mass is lost on producing cell protein and lipid. Obtained yields are one third to one tenth of the theoretical ones. Wasted energy from captured photons is a major loss term and a major challenge in maximising mass algal production. Using irradiance data and kinetic parameters derived from reported field studies, we produce a simple model of algal biomass production and its variation with latitude and lipid content. An economic analysis of algal biomass production considers a number of scenarios and the effect of changing individual parameters. Our main conclusions are that: (i) the biochemical composition of the biomass influences the economics, in particular, increased lipid content reduces other valuable compounds in the biomass; (ii) the "biofuel only" option is unlikely to be economically viable; and (iii) among the hardest problems in assessing the economics are the cost of the CO2 supply and uncertain nature of downstream processing. We conclude by considering the pressing research and development needs.

Genetic Control of Biochemical Reactions in Neurospora

1941-11-15

G. W. Beadle , E. L. Tatum

Gene expression variation is shaped by both genetic and environmental effects, yet these two factors are rarely considered together in the context of adaptive evolution. We studied environmental influences on … Gene expression variation is shaped by both genetic and environmental effects, yet these two factors are rarely considered together in the context of adaptive evolution. We studied environmental influences on gene regulatory evolution in ...Changes in gene expression are thought to play a major role in adaptive evolution. While it is known that gene expression is highly sensitive to the environment, very few studies have determined the influence of genetic and environmental effects on ...

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Photoinhibition of photosynthesis in natural assemblages of marine phytoplankton

1980-01-01

T. Platt , Charles L. Gallegos , W. G. Harrison

Algal–bacterial processes for the treatment of hazardous contaminants: A review

2006-08-01

Raúl Muñoz , Benoı̂t Guieysse

CO2 bio-mitigation using microalgae

2008-05-15

Bei Wang , Yanqun Li , Nan Wu +1 more

An Outlook on Microalgal Biofuels

2010-08-12

René H. Wijffels , María J. Barbosa

Microalgae are considered one of the most promising feedstocks for biofuels. The productivity of these photosynthetic microorganisms in converting carbon dioxide into carbon-rich lipids, only a step or two away … Microalgae are considered one of the most promising feedstocks for biofuels. The productivity of these photosynthetic microorganisms in converting carbon dioxide into carbon-rich lipids, only a step or two away from biodiesel, greatly exceeds that of agricultural oleaginous crops, without competing for arable land. Worldwide, research and demonstration programs are being carried out to develop the technology needed to expand algal lipid production from a craft to a major industrial process. Although microalgae are not yet produced at large scale for bulk applications, recent advances-particularly in the methods of systems biology, genetic engineering, and biorefining-present opportunities to develop this process in a sustainable and economical way within the next 10 to 15 years.

Microalgal biomarkers: A review of recent research developments

1998-11-01

John K. Volkman , Stephanie M. Barrett , Susan I. Blackburn +3 more

Lipid productivity as a key characteristic for choosing algal species for biodiesel production

2009-01-05

Melinda J. Griffiths , Susan T.L. Harrison

Cultivation, photobioreactor design and harvesting of microalgae for biodiesel production: A critical review

2010-07-11

Chun‐Yen Chen , Kuei-Ling Yeh , Rifka Aisyah +2 more

Microalgae for oil: Strain selection, induction of lipid synthesis and outdoor mass cultivation in a low‐cost photobioreactor

2008-06-18

Liliana Rodolfi , Graziella Chini Zittelli , Niccoló Bassi +4 more

Thirty microalgal strains were screened in the laboratory for their biomass productivity and lipid content. Four strains (two marine and two freshwater), selected because robust, highly productive and with a … Thirty microalgal strains were screened in the laboratory for their biomass productivity and lipid content. Four strains (two marine and two freshwater), selected because robust, highly productive and with a relatively high lipid content, were cultivated under nitrogen deprivation in 0.6-L bubbled tubes. Only the two marine microalgae accumulated lipid under such conditions. One of them, the eustigmatophyte Nannochloropsis sp. F&M-M24, which attained 60% lipid content after nitrogen starvation, was grown in a 20-L Flat Alveolar Panel photobioreactor to study the influence of irradiance and nutrient (nitrogen or phosphorus) deprivation on fatty acid accumulation. Fatty acid content increased with high irradiances (up to 32.5% of dry biomass) and following both nitrogen and phosphorus deprivation (up to about 50%). To evaluate its lipid production potential under natural sunlight, the strain was grown outdoors in 110-L Green Wall Panel photobioreactors under nutrient sufficient and deficient conditions. Lipid productivity increased from 117 mg/L/day in nutrient sufficient media (with an average biomass productivity of 0.36 g/L/day and 32% lipid content) to 204 mg/L/day (with an average biomass productivity of 0.30 g/L/day and more than 60% final lipid content) in nitrogen deprived media. In a two-phase cultivation process (a nutrient sufficient phase to produce the inoculum followed by a nitrogen deprived phase to boost lipid synthesis) the oil production potential could be projected to be more than 90 kg per hectare per day. This is the first report of an increase of both lipid content and areal lipid productivity attained through nutrient deprivation in an outdoor algal culture. The experiments showed that this marine eustigmatophyte has the potential for an annual production of 20 tons of lipid per hectare in the Mediterranean climate and of more than 30 tons of lipid per hectare in sunny tropical areas.

Life-Cycle Assessment of Biodiesel Production from Microalgae

2009-07-27

Laurent Lardon , Arnaud Hélias , Bruno Sialve +2 more

This paper provides an analysis of the potential environmental impacts of biodiesel production from microalgae. High production yields of microalgae have called forth interest of economic and scientific actors but … This paper provides an analysis of the potential environmental impacts of biodiesel production from microalgae. High production yields of microalgae have called forth interest of economic and scientific actors but it is still unclear whether the production of biodiesel is environmentally interesting and which transformation steps need further adjustment and optimization. A comparative LCA study of a virtual facility has been undertaken to assessthe energetic balance and the potential environmental impacts of the whole process chain, from the biomass production to the biodiesel combustion. Two different culture conditions, nominal fertilizing or nitrogen starvation, as well as two different extraction options, dry or wet extraction, have been tested. The best scenario has been compared to first generation biodiesel and oil diesel. The outcome confirms the potential of microalgae as an energy source but highlights the imperative necessity of decreasing the energy and fertilizer consumption. Therefore control of nitrogen stress during the culture and optimization of wet extraction seem to be valuable options. This study also emphasizes the potential of anaerobic digestion of oilcakes as a way to reduce external energy demand and to recycle a part of the mineral fertilizers.

High-value products from microalgae—their development and commercialisation

2013-01-28

Michael A. Borowitzka

ALGAL CULTURING TECHNIQUES

2005-08-01

Senjie Lin

Effect of temperature and nitrogen concentration on the growth and lipid content of Nannochloropsis oculata and Chlorella vulgaris for biodiesel production

2009-04-02

Attílio Converti , Alessandro Alberto Casazza , Erika Y. Ortiz +2 more

Valuable products from biotechnology of microalgae

2004-08-05

Otto Pulz , Wolfgang Groß

Microalgae for biodiesel production and other applications: A review

2009-08-04

Teresa M. Mata , António A. Martins , Nídia S. Caetano

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Biodiesel from algae: challenges and prospects

2010-04-18

Stuart A. Scott , Matthew P. Davey , John S. Dennis +4 more

Biofuels from microalgae—A review of technologies for production, processing, and extractions of biofuels and co-products

2009-10-30

Liam Brennan , Philip Owende

Nutrient recovery from wastewater streams by microalgae: Status and prospects

2012-12-12

Ting Cai , Stephen Y. Park , Yebo Li

Microalgae and wastewater treatment

2012-05-03

Neveen Abdel-Raouf , Ali A. Al-Homaidan , Ibraheem Ibraheem

Organic and inorganic substances which were released into the environment as a result of domestic, agricultural and industrial water activities lead to organic and inorganic pollution. The normal primary and … Organic and inorganic substances which were released into the environment as a result of domestic, agricultural and industrial water activities lead to organic and inorganic pollution. The normal primary and secondary treatment processes of these wastewaters have been introduced in a growing number of places, in order to eliminate the easily settled materials and to oxidize the organic material present in wastewater. The final result is a clear, apparently clean effluent which is discharged into natural water bodies. This secondary effluent is, however, loaded with inorganic nitrogen and phosphorus and causes eutrophication and more long-term problems because of refractory organics and heavy metals that are discharged. Microalgae culture offers an interesting step for wastewater treatments, because they provide a tertiary biotreatment coupled with the production of potentially valuable biomass, which can be used for several purposes. Microalgae cultures offer an elegant solution to tertiary and quandary treatments due to the ability of microalgae to use inorganic nitrogen and phosphorus for their growth. And also, for their capacity to remove heavy metals, as well as some toxic organic compounds, therefore, it does not lead to secondary pollution. In the current review we will highlight on the role of micro-algae in the treatment of wastewater.

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Production and harvesting of microalgae for wastewater treatment, biofuels, and bioproducts

2011-06-05

Logan Christenson , Ronald C. Sims

Recovery of microalgal biomass and metabolites: process options and economics

2002-12-28

E. Molina Grima , El‐Hassan Belarbi , Gabriel Acién +2 more

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Second Generation Biofuels: High-Efficiency Microalgae for Biodiesel Production

2008-03-01

Peer M. Schenk , Skye R. Thomas‐Hall , Evan Stephens +5 more

Commercial production of microalgae: ponds, tanks, tubes and fermenters

1999-04-01

Michael A. Borowitzka

Heterotrophic cultures of microalgae: Metabolism and potential products

2010-08-31

Octavio Perez‐Garcia , Froylán M. E. Escalante , Luz E. de‐Bashan +1 more

CO2 CONCENTRATING MECHANISMS IN ALGAE: Mechanisms, Environmental Modulation, and Evolution

2005-01-15

Mario Giordano , John Beardall , John A. Raven

The evolution of organisms capable of oxygenic photosynthesis paralleled a long-term reduction in atmospheric CO2 and the increase in O2. Consequently, the competition between O2 and CO2 for the active … The evolution of organisms capable of oxygenic photosynthesis paralleled a long-term reduction in atmospheric CO2 and the increase in O2. Consequently, the competition between O2 and CO2 for the active sites of RUBISCO became more and more restrictive to the rate of photosynthesis. In coping with this situation, many algae and some higher plants acquired mechanisms that use energy to increase the CO2 concentrations (CO2 concentrating mechanisms, CCMs) in the proximity of RUBISCO. A number of CCM variants are now found among the different groups of algae. Modulating the CCMs may be crucial in the energetic and nutritional budgets of a cell, and a multitude of environmental factors can exert regulatory effects on the expression of the CCM components. We discuss the diversity of CCMs, their evolutionary origins, and the role of the environment in CCM modulation.

Culture of Phytoplankton for Feeding Marine Invertebrates

1975-01-01

Robert R. L. Guillard

Nile red: a selective fluorescent stain for intracellular lipid droplets.

1985-03-01

Phillip Greenspan , Eugene P. Mayer , Stanley D. Fowler

We report that the dye nile red, 9-diethylamino-5H-benzo[alpha]phenoxazine-5-one, is an excellent vital stain for the detection of intracellular lipid droplets by fluorescence microscopy and flow cytofluorometry. The specificity of the … We report that the dye nile red, 9-diethylamino-5H-benzo[alpha]phenoxazine-5-one, is an excellent vital stain for the detection of intracellular lipid droplets by fluorescence microscopy and flow cytofluorometry. The specificity of the dye for lipid droplets was assessed on cultured aortic smooth muscle cells and on cultured peritoneal macrophages that were incubated with acetylated low density lipoprotein to induce cytoplasmic lipid overloading. Better selectivity for cytoplasmic lipid droplets was obtained when the cells were viewed for yellow-gold fluorescence (excitation, 450-500 nm; emission, greater than 528 nm) rather than red fluorescence (excitation, 515-560 nm; emission, greater than 590 nm). Nile red-stained, lipid droplet-filled macrophages exhibited greater fluorescence intensity than did nile red-stained control macrophages, and the two cell populations could be differentiated and analyzed by flow cytofluorometry. Such analyses could be performed with either yellow-gold or red fluorescence, but when few lipid droplets per cell were present, the yellow-gold fluorescence was more discriminating. Nile red exhibits properties of a near-ideal lysochrome. It is strongly fluorescent, but only in the presence of a hydrophobic environment. The dye is very soluble in the lipids it is intended to show, and it does not interact with any tissue constituent except by solution. Nile red can be applied to cells in an aqueous medium, and it does not dissolve the lipids it is supposed to reveal.

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COMPLEMENTARY CHROMATIC ADAPTATION IN A FILAMENTOUS BLUE-GREEN ALGA

1973-08-01

Allen Bennett , Lawrence Bogorad

Fluorescent and red light environments generate greatly different patterns of pigmentation and morphology in Fremyella diplosiphon. Most strikingly, red-illuminated cultures contain no measurable C-phycoerythrin and have a mean filament length … Fluorescent and red light environments generate greatly different patterns of pigmentation and morphology in Fremyella diplosiphon. Most strikingly, red-illuminated cultures contain no measurable C-phycoerythrin and have a mean filament length about 10 times shorter than fluorescent-illuminated cultures. C-phycoerythrin behaves as a photoinducible constituent of this alga. Spectrophotometric and immunochemical procedures were devised so that C-phycoerythrin metabolism could be studied quantitatively with [14C]-phenylalanine pulse-chased cultures. Transfer of red-illuminated cultures to fluorescent light initiates C-phycoerythrin production by essentially de novo synthesis. C-phycoerythrin is not degraded to any significant extent in cultures continuously illuminated with fluorescent light. Transfer of fluorescent-illuminated cultures to red light causes an abrupt cessation of C-phycoerythrin synthesis. The C-phycoerythrin content of cultures adapting to red light decreases and subsequently becomes constant. Loss of C-phycoerythrin is not brought about by metabolic degradation, but rather by a decrease in mean filament length which is effected by transcellular breakage. In this experimental system, light influences intracellular C-phycoerythrin levels by regulating the rate of synthesis of the chromoprotein.

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Microalgae as a raw material for biofuels production

2008-11-03

Luísa Gouveia , Ana Cristina Oliveira

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Biodiesel from microalgae

2007-02-14

Yusuf Chisti

Anaerobic digestion of microalgae as a necessary step to make microalgal biodiesel sustainable

2009-03-15

Bruno Sialve , Nicolas Bernet , Olivier Bernard

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Microalgal triacylglycerols as feedstocks for biofuel production: perspectives and advances

2008-05-01

Qiang Hu , Milton R. Sommerfeld , Eric Jarvis +4 more

Summary Microalgae represent an exceptionally diverse but highly specialized group of micro‐organisms adapted to various ecological habitats. Many microalgae have the ability to produce substantial amounts (e.g. 20–50% dry cell … Summary Microalgae represent an exceptionally diverse but highly specialized group of micro‐organisms adapted to various ecological habitats. Many microalgae have the ability to produce substantial amounts (e.g. 20–50% dry cell weight) of triacylglycerols (TAG) as a storage lipid under photo‐oxidative stress or other adverse environmental conditions. Fatty acids, the building blocks for TAGs and all other cellular lipids, are synthesized in the chloroplast using a single set of enzymes, of which acetyl CoA carboxylase (ACCase) is key in regulating fatty acid synthesis rates. However, the expression of genes involved in fatty acid synthesis is poorly understood in microalgae. Synthesis and sequestration of TAG into cytosolic lipid bodies appear to be a protective mechanism by which algal cells cope with stress conditions, but little is known about regulation of TAG formation at the molecular and cellular level. While the concept of using microalgae as an alternative and renewable source of lipid‐rich biomass feedstock for biofuels has been explored over the past few decades, a scalable, commercially viable system has yet to emerge. Today, the production of algal oil is primarily confined to high‐value specialty oils with nutritional value, rather than commodity oils for biofuel. This review provides a brief summary of the current knowledge on oleaginous algae and their fatty acid and TAG biosynthesis, algal model systems and genomic approaches to a better understanding of TAG production, and a historical perspective and path forward for microalgae‐based biofuel research and commercialization.

The potential of sustainable algal biofuel production using wastewater resources

2010-07-02

Jon K. Pittman , Andrew P. Dean , Olumayowa Osundeko

Micro-algae as a source of protein

2006-11-29

E. W. Becker

Commercial applications of microalgae

2006-02-01

Pauline Spolaore , Claire Joannis‐Cassan , Elie Duran +1 more

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YELLOW‐GREEN ALGAE WITH CHLOROPHYLLIDE C1,2

1972-03-01

Robert R. L. Guillard , Carl J. Lorenzen

SUMMARY Chlorophyllide c (chlorophyll c) wax found in axenic or unialgal cultures of 5 members of the class Xanthophyceae and in 2 members of the class Raphidophyceae (Chloromonadophyceae). Two other … SUMMARY Chlorophyllide c (chlorophyll c) wax found in axenic or unialgal cultures of 5 members of the class Xanthophyceae and in 2 members of the class Raphidophyceae (Chloromonadophyceae). Two other algae contained no chl c; neither had chl b. One of these plants, Pleurochloris magna , is presumably a member of the newly named class Eustigmatophyceae (Hibberd and Leedale). The other alga, clone GSB Sticho, is of uncertain, systematic position. Although, the xanthophyll pigments were not critically studied, there is enough evidence, to permit the conclusion that the xanthophyll suites of the chloromonads, the xanthophytes, P. magna , and clone GSB Sticho all differ in at least one respect.

Comparison of several methods for effective lipid extraction from microalgae

2009-04-22

Jae-Yon Lee , Chan Yul Yoo , So‐Young Jun +2 more

Micro‐algal biotechnology

1988-09-26

Lyndon J. Rogers

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The promising future of microalgae: current status, challenges, and optimization of a sustainable and renewable industry for biofuels, feed, and other products

2018-03-05

Muhammad Imran Khan , Jin Hyuk Shin , Jong Deog Kim

Microalgae have recently attracted considerable interest worldwide, due to their extensive application potential in the renewable energy, biopharmaceutical, and nutraceutical industries. Microalgae are renewable, sustainable, and economical sources of biofuels, … Microalgae have recently attracted considerable interest worldwide, due to their extensive application potential in the renewable energy, biopharmaceutical, and nutraceutical industries. Microalgae are renewable, sustainable, and economical sources of biofuels, bioactive medicinal products, and food ingredients. Several microalgae species have been investigated for their potential as value-added products with remarkable pharmacological and biological qualities. As biofuels, they are a perfect substitute to liquid fossil fuels with respect to cost, renewability, and environmental concerns. Microalgae have a significant ability to convert atmospheric CO

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Purification and properties of unicellular blue-green algae (order Chroococcales).

1971-01-01

Roger Y. Stanier , R Kunisawa , M Mandel +1 more

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Sequence Analysis of the Genome of the Unicellular Cyanobacterium Synechocystis sp. Strain PCC6803. II. Sequence Determination of the Entire Genome and Assignment of Potential Protein-coding Regions

1996-01-01

Takakazu Kaneko , Shusei Sato , Haruru Kotani +7 more

The sequence determination of the entire genome of the Synechocystis sp. strain PCC6803 was completed. The total length of the genome finally confirmed was 3,573,470 bp, including the previously reported … The sequence determination of the entire genome of the Synechocystis sp. strain PCC6803 was completed. The total length of the genome finally confirmed was 3,573,470 bp, including the previously reported sequence of 1,003,450 bp from map position 64% to 92% of the genome. The entire sequence was assembled from the sequences of the physical map-based contigs of cosmid clones and of λ clones and long PCR products which were used for gap-filling. The accuracy of the sequence was guaranteed by analysis of both strands of DNA through the entire genome. The authenticity of the assembled sequence was supported by restriction analysis of long PCR products, which were directly amplified from the genomic DNA using the assembled sequence data. To predict the potential protein-coding regions, analysis of open reading frames (ORFs), analysis by the GeneMark program and similarity search to databases were performed. As a result, a total of 3,168 potential protein genes were assigned on the genome, in which 145 (4.6%) were identical to reported genes and 1,257 (39.6%) and 340 (10.8%) showed similarity to reported and hypothetical genes, respectively. The remaining 1,426 (45.0%) had no apparent similarity to any genes in databases. Among the potential protein genes assigned, 128 were related to the genes participating in photosynthetic reactions. The sum of the sequences coding for potential protein genes occupies 87% of the genome length. By adding rRNA and tRNA genes, therefore, the genome has a very compact arrangement of protein- and RNA-coding regions. A notable feature on the gene organization of the genome was that 99 ORFs, which showed similarity to transposase genes and could be classified into 6 groups, were found spread all over the genome, and at least 26 of them appeared to remain intact. The result implies that rearrangement of the genome occurred frequently during and after establishment of this species.

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The Molecular Biology of Cyanobacteria

1994-01-01

Donald A. Bryant

Microalgae: biotechnology and microbiology

1994-10-01

E. W. Becker

1. Introduction 2. Algal production systems 3. Culture media 4. Cultivation methods (indoors) 5. Scaling up 6. Algal grouping 7. Strain selection 8. Growth kinetics 9. Measurement of algal growth … 1. Introduction 2. Algal production systems 3. Culture media 4. Cultivation methods (indoors) 5. Scaling up 6. Algal grouping 7. Strain selection 8. Growth kinetics 9. Measurement of algal growth 10. Large scale cultivation 11. Yield 12. Chemical composition 13. Nutrition 14. Applications of algae 15. Addresses of algae culture collections.

Novel algal modular LOV domain proteins expand opto-biotechnological avenues for controlling of eukaryotic riboswitching, translational and proteolytic processes.

2025-06-25

Manisha Singh , Rajani Singh , Suneel Kateriya | bioRxiv (Cold Spring Harbor Laboratory)

Light, Oxygen, or Voltage (LOV) domains mediate blue light-gated signal transduction, regulating diverse opto-biological functions. LOV domain functions either standalone or fused with effector domains, regulating the downstream signalling process. … Light, Oxygen, or Voltage (LOV) domains mediate blue light-gated signal transduction, regulating diverse opto-biological functions. LOV domain functions either standalone or fused with effector domains, regulating the downstream signalling process. The current repertoire of LOV domain-based tools is limited to a relatively small number of naturally occurring proteins. In this study, we have identified novel algal LOV domain fused with different effector domains as potential light-mediated translational, ribogenetic and proteolytic switches, highlighting their unexplored avenues of opto-biotechnology. LOV-domain fusion with eIF4E suggests its potential as a light-controlled translational switch and as an opto-ribogenetic regulator. LOV-SppA might be used as a light-gated proteolytic switch. Additionally, LOV coupled with UFD1, UbiH, mannosyl-oligosaccharide glucosidase and biosynthetic gene cluster (BCG) molecular chassis pave the way for opto-biomanufacturing strategies of relevant valuable algal bioactive. Here, we report the discovery of 13 novel algal modular LOV domain-containing proteins across the algal system through comprehensive bioinformatics, bio-curation and systems biology approaches. It offers important insights into the structural and functional diversity of LOV photoreceptors in algae. Hence, these newly identified modular LOV domain-containing proteins expand the platform of opto-biotechnology applications. These finding lay the foundation for future research on the mechanistic basis for light-driven signalling cascade of RNA, translational and protein homeostasis in algae, and potentiate development of next-generation opto-biotechnological tools for synthetic biology, optogenetics and opto-biomanufacturing of valuable bioactive via regulation of biosynthetic gene cluster (BGC) in green lineage.

Charting the academic output on cyanobacterial exopolysaccharides and their industrial applications

2025-06-25

Maricel Bocăneală , Giovani Moise Goron , Elena Rákosy-Tican | Studia Universitatis Babeş-Bolyai Biologia

Cyanobacterial exopolysaccharides (EPS) are diverse biopolymers with significant ecological roles and growing industrial potential due to their biocompatibility, biodegradability, and functional versatility. This study presents a bibliometric and patent analysis … Cyanobacterial exopolysaccharides (EPS) are diverse biopolymers with significant ecological roles and growing industrial potential due to their biocompatibility, biodegradability, and functional versatility. This study presents a bibliometric and patent analysis of cyanobacterial EPS research between 2004 and 2023, exploring academic and industrial advancements. The bibliometric analysis of 1,022 articles identified pharmaceuticals and environmental applications as dominant research themes, while the food, agriculture, and energy sectors showed emerging interest. A manually curated subset of 79 articles focusing on industrial applications highlighted EPS’s potential in pollutant removal, drug development, and biofertilization. Patent analysis, with data from 618 entries, revealed a surge in filings post-2014, predominantly in the USA, reflecting growing industrial interest. While healthcare and environmental sectors lead in EPS applications, translational gaps between academic research and industrial adoption persist, particularly in underdeveloped domains. This study presents the multidisciplinary appeal of cyanobacterial EPS, striving to offer insights into future research directions and their potential for sustainable innovation across diverse sectors. Article history: Received 4 February 2025; Revised 17 March 2025; Accepted 17 March 2025; Available online 25 June 2025

Optimizing microalgae cultivation for enhanced lutein production: screening of high-yield strains and cultivation strategy development

2025-06-25

Yuelian Li , Han Sun , Yunlei Fu +2 more | Journal of Applied Phycology

Algae-bacteria symbiotic biofilm system for low carbon nitrogen removal from municipal wastewater: A review

2025-06-25

Zhiyuan Liang , Ying Zhao , Hongbing Ji +1 more | World Journal of Microbiology and Biotechnology

DSC and optical investigation of Spirulina platensis suspension and wet mass subjected to rapid freezing at − 20 °C, − 80 °C, and − 196 °C

2025-06-24

Jamlet Monaselidze , Evgeni Kiziria , Eteri Gelagutashvi +6 more | Journal of Thermal Analysis and Calorimetry

Low-salinity medium for large-scale biomass production of the marine purple photosynthetic bacterium Rhodovulum sulfidophilum

2025-06-24

Shamitha Rao Morey‐Yagi , Dao Duy Hanh , Miki Suzuki +7 more | PLoS ONE

Marine purple non-sulfur bacteria such as Rhodovulum sulfidophilum are versatile due to their diverse applications in bioremediation, biotechnological production of useful materials, industrial production of value-added compounds, and agricultural fertilizers. … Marine purple non-sulfur bacteria such as Rhodovulum sulfidophilum are versatile due to their diverse applications in bioremediation, biotechnological production of useful materials, industrial production of value-added compounds, and agricultural fertilizers. Our previous study demonstrated the potential of its lysed and dried biomass as a nitrogen fertilizer for plant production. However, large-scale fertilizer production requires scaling up the culture to larger volumes, which is not cost-effective with currently available options for growth media. In this study, we tested a seawater-based, cost-effective alternative to the commonly used nutrient-rich culture medium for the growth of this bacterium. We found that reducing salinity from 3% to 1.2% had no adverse effects on its heterotrophic growth, dry cell yield, nitrogen content, and total amino acid composition. The nitrogen content and the weight percent of free lysine, aspartic acid, and glutamate tended to increase in the biomass obtained from cultures grown at 1.2% salinity. Under autotrophic conditions, decreasing salinity to 1.2% did not affect cell growth, final dry cell yields, and total carbon assimilation, but N assimilation remained higher. Reducing salinity to 1.2% proved to be cost-effective and feasible for the cultivation of R. sulfidophilum without increasing the risk of contamination, providing a viable alternative for its large-scale cultivation and application as a plant nitrogen fertilizer.

Effects of Salinity on the Growth Performance and Docosahexaenoic Acid Positional Distribution in Triacylglycerols of the Newly Isolated Schizochytrium sp. FJ-1

2025-06-23

Sitong Ye , Xiaonan Wang , Youcai Zhou +7 more | Marine Drugs

Schizochytrium-derived omega-3 polyunsaturated fatty acids (e.g., docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)) are proven to be health-beneficial bioactive substances that have been widely applied in the pharmaceutical, nutraceutical, and … Schizochytrium-derived omega-3 polyunsaturated fatty acids (e.g., docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)) are proven to be health-beneficial bioactive substances that have been widely applied in the pharmaceutical, nutraceutical, and food industries. In this work, the newly isolated Schizochytrium sp. FJ-1 strain was selected to investigate the effects of salinity on the growth performance, lipid production, DHA yield, and positional distribution of triacylglycerols (TAGs). In addition, Schizochytrium sp. 20888 was used as a control strain. The obtained results showed that Schizochytrium sp. FJ-1 could grow with a low biomass in the absence of sea salt; however, Schizochytrium sp. 20888 did not grow in the medium without sea salt. Moreover, Schizochytrium sp. FJ-1 achieved the highest biomass in 10‰ salinity, whilst Schizochytrium sp. 20888 attained the greatest biomass in 40‰ salinity. In terms of the total lipid content and TAG fraction percentage, Schizochytrium sp. FJ-1 grown in 5–20‰ salinity had high total lipid contents (57.04–60.02%), with TAGs accounting for over 90% of the lipid fraction. The highest DHA contents for total lipids (41.38%) and TAGs (40.18%) were obtained when Schizochytrium sp. FJ-1 was grown under 10‰ salinity conditions. Additionally, under the same culture condition, EPA contents of lipids and TAGs were significantly higher for Schizochytrium sp. FJ-1 compared with Schizochytrium sp. 20888. Furthermore, nuclear magnetic resonance analysis found that the salinity level had a distinct impact on the positional distribution of DHA in TAGs in these two Schizochytrium strains. Schizochytrium sp. FJ-1 grown under 40‰ salinity conditions produced TAGs with the greatest percentage of sn-2 DHA (81.24%). The percentages were higher than those found for the other groups of this microalga and Schizochytrium sp. 20888. Taken together, Schizochytrium sp. FJ-1 could be a potential candidate to produce highly valued DHA lipids or TAG bioproducts by regulating salinity.

Genomes of Cyanobacteria

2025-06-23

Senjie Lin | CRC Press eBooks

Review of Advances in Algae as an Energy Source

2025-06-23

Deema Darwish , Bassam Abu-Hijleh | Circular Economy and Sustainability

An Integrated Biorefinery Process to Revalorize Marine Biomass from the Microalga Nannochloropsis gaditana Using Pressurized Green Solvents

2025-06-23

Cristina Blanco-Llamero , Paz García-García , Francisco J. Señoráns | Marine Drugs

Biorefinery is gaining attention as a promising approach to valorize natural resources and promote a circular bioeconomy. This study aimed to recover high-value molecules, such as xanthophylls and polar lipids … Biorefinery is gaining attention as a promising approach to valorize natural resources and promote a circular bioeconomy. This study aimed to recover high-value molecules, such as xanthophylls and polar lipids with nutraceutical applications, through enzymatic pretreatment and sequential pressurized liquid extraction (PLEseq), by reusing the residual biomass of Nannochloropsis gaditana after each processing step. Remarkably, pure glycolipids (102.95 ± 1.10 mg g−1 dry weight) were obtained immediately after enzymatic pretreatment, facilitating their easy recovery. Furthermore, two alternative sequential extraction processes were successfully developed, using ethanol and water as green solvents at varying temperatures and in different orders. The most effective PLEseq conditions yielded up to 48 mg mL−1 of carbohydrates using water at 50 °C, and up to 44 mg mL−1 of proteins via subcritical water extraction at 100 °C, prior to conventional lipid extraction with ethanol to produce various concentrated extracts. In the inverted PLEseq process—starting with ethanol extraction followed by successive water washes—isolated and purified fractions of lutein and astaxanthin were obtained, contributing to the complete depletion of the residual biomass. Overall, the development of an integrated and sequential biorefinery protocol that enables the extraction of multiple high-value compounds holds significant potential for application in the food industry.

Advances and Perspectives of Microalgal Biorefineries for Bioenergy

2025-06-23

Sonia Choudhary , Gautam Venkatrayalu , Boda Ravi Kiran +1 more | Energy & Fuels

Evolution of Algae and Photosynthesis

2025-06-23

Senjie Lin | CRC Press eBooks

A circular economy approach for sustainable biohydrogen, activated carbon and biofertilizers in a microalgae-based wastewater treatment

2025-06-21

Dulce M. Arias , Martín Barragán‐Trinidad , Angélica Guillén-Garcés +3 more | International Journal of Hydrogen Energy

Synergizing mechanistic and AI models for deeper insights into algal-bacterial systems in sustainable wastewater treatment

2025-06-21

Xianghua Wen , Xin Sun , Xingyu Liu | Journal of Water Process Engineering

Angular 6/6/5/6-Annelated Pyrrolidine-2,3-Diones: Growth-Regulating Activity in Chlorella vulgaris

2025-06-21

Anastasia Novokshonova , Pavel Khramtsov , Ekaterina E. Khramtsova | Chemistry

Chlorella vulgaris, a unicellular microalga with broad industrial applications, is a valuable source of bioactive compounds, including proteins, pigments, and lipids. However, optimizing its growth and metabolite production remains a … Chlorella vulgaris, a unicellular microalga with broad industrial applications, is a valuable source of bioactive compounds, including proteins, pigments, and lipids. However, optimizing its growth and metabolite production remains a challenge. This study investigates the potential of angular 6/6/5/6-annelated pyrrolidine-2,3-diones—structurally complex small molecules resembling alkaloids and 13(14 → 8)abeo-steroids—as novel growth stimulants for C. vulgaris. A series of these compounds (20 structurally diverse derivatives, including 7 previously unreported ones) were synthesized and screened for their ability to enhance microalgal growth. Primary screening identified one compound as a promising candidate, significantly increasing algae cell concentration in microplate cultures. Subsequent validation in flask-scale experiments revealed that this candidate induced a 19% increase in protein content at 1 μmol/L, suggesting potential for protein enrichment in algal biomass. Stability studies of the candidate compound revealed its significant hydrolytic degradation in aqueous media. These findings highlight the potential of angular 6/6/5/6-annelated pyrrolidine-2,3-diones as modulators of microalgal metabolism, offering a new avenue for enhancing C. vulgaris biomass quality, particularly for protein-rich applications in the food and feed industries.

The Cecal Distribution of Microalgal Pigments in Rats: Do Carotenoids and Chlorophylls Play a Pharmacobiotic Role?

2025-06-21

Tatiele Casagrande do Nascimento , Patrícia Acosta Caetano , Marcylene Vieira da Silveira +7 more | Foods

This study investigated the cecal distribution of lipophilic pigments (carotenoids and chlorophylls) from Scenedesmus obliquus and their effects on the activity of the intestinal microbiota in rats. Oleoresins containing different … This study investigated the cecal distribution of lipophilic pigments (carotenoids and chlorophylls) from Scenedesmus obliquus and their effects on the activity of the intestinal microbiota in rats. Oleoresins containing different concentrations of microalgal pigments (from 0 to 600 µg·kg−1bw·d−1), previously characterized by chromatographic and spectrometric analyses, were administered for four weeks. At the end of the intervention, cecal content samples were collected and analyzed for their pigment composition, short-chain fatty acids (SCFAs), and probiotic microbiota. Nine pigments were identified in the cecal samples, with all-trans-zeaxanthin and pheophytin being the most abundant in all groups. Furthermore, 15-cis-lutein, all-trans-β-cryptoxanthin, and 9-cis-β-carotene—found exclusively in microalgal oleoresin—were detected only in animals receiving doses above 300 µg·kg−1bw.day−1, indicating a link with the SCFA modulation. These supplementations significantly increased the levels of acetate (300 and 450 µg·kg−1bw·d−1 −13% and 14%), butyrate (300 µg kg−1bw·d−1 −19%), and propionate (600 µg·kg−1bw·d−1 −16%). Notably, 300 µg·kg−1bw·d−1 significantly increased Bifidobacterium and Lactobacillus populations. Overall, the pigment supplementation positively influenced the gut microbiota composition and SCFA production in a dose-dependent manner, particularly at 300 µg·kg−1bw·d−1. These results support the potential application of microalgal pigments as functional food ingredients or supplements with gut health benefits.

Investigating Alternative Solvents Regarding Extractability of Lipophilic Food Ingredients in Spinach-Tomato Powder and Algae Materials

2025-06-21

Mario Schmidt , Volker Böhm | Food Analytical Methods

Abstract Extraction of natural products such as carotenoids, vitamin E and chlorophylls is still accompanied with certain challenges. Limitations exist in widespread availability of sophisticated techniques (e.g. supercritical fluid), which … Abstract Extraction of natural products such as carotenoids, vitamin E and chlorophylls is still accompanied with certain challenges. Limitations exist in widespread availability of sophisticated techniques (e.g. supercritical fluid), which are often replaced by conventional approaches such as tissue homogeniser with disperser blades, a sonication bath or vortex mixing. Moreover, an appropriate selection of solvents is a critical step for selective extraction of compounds in complex, severely extractable matrices. The present investigation focussed on a comparison of conventional solvents (e.g. tetrahydrofuran, acetone, hexane) with more sustainable alternatives (e.g. 2-methyl-tetrahydrofuran (2-MeTHF); dimethyl carbonate (DMC); cyclopentyl methyl ether (CPME)) with and without addition of methanol regarding a broad range of analyte polarities. Herein, tetrahydrofuran with methanol resulted in maximum extraction efficiencies for total carotenoids in a spinach tomato powder. 2-MeTHF, DMC and CPME partially combined with MeOH proved to be equivalent alternatives for extraction of xanthophylls and β-carotene isomers. A comparison of renowned and widely available extraction techniques in context of challenging sample matrices (dried, pelletised and fresh microalgae) resulted in preferably powerful approaches such as Ultra-Turrax® homogenisation and sonifier probe application. Necessary pretreatments with methanol combined with powerful extraction techniques were apparently recommendable for dried algae products compared to fresh algae paste, thus reducing the potential extraction repetitions. Finally, a comparison of different syringe filter materials suggested the use of mixed cellulose ester (MCE) membranes for avoiding a significant loss ( p < 0.05) of analytes (lutein, β-carotene, lycopene, vitamin E) compared to seven other membrane materials. Overall, these results represent a contribution to routine analysis of lipophilic food ingredients with a high transferability and adaptability across applied research.

Current contributions of microalgae in global biofuel production; cultivation techniques, biofuel varieties and promising industrial ventures

2025-06-21

Fathima Zahra Nashath , Yan Jer Ng , Kuan Shiong Khoo +1 more | Biomass and Bioenergy

Preparation and Evaluation of Peel-Off Gel Mask from Spirulina Platensis Microalgae Water Extract

2025-06-21

Zabilla Kirani , Billy Harnaldo Putra , Nola Rahmadasmi +6 more | Journal of Pharmaceutical And Sciences

Background: The microalgae Spirulina platensis is a microalgae with numerous benefits, particularly in the fields of health and cosmetics. One of its active compounds, phycocyanin, is a water-soluble antioxidant that … Background: The microalgae Spirulina platensis is a microalgae with numerous benefits, particularly in the fields of health and cosmetics. One of its active compounds, phycocyanin, is a water-soluble antioxidant that is beneficial for facial skincare. A peel-off gel mask is a practical cosmetic product that can be peeled off directly after drying. Objective: This study aimed to develop a peel-off gel mask containing Spirulina platensis water extract and evaluate its physical quality. Methods: The peel-off gel mask was prepared by adding Spirulina platensis water extract at three different concentrations: 0.25% (F1), 0.5% (F2), and 0.75% (F3). Physical quality evaluation included organoleptic testing, homogeneity, viscosity, pH, drying time, adhesiveness, and stability at 4°C and 40°C. A comparison was also made with a commercial spirulina mask product (F4, 0.25%). Results: The physical quality assessment showed that all formulations met the requirements for organoleptic properties, homogeneity, viscosity, pH, drying time, and adhesiveness. In the stability test, the base formula (F0) and F1 (0.25%) were the most stable in terms of organoleptic parameters, while all formulations remained stable in pH. The viscosity of all four formulations remained stable after two months of storage. The commercial mask (F4) exhibited similar physical quality results to F1, with both meeting all requirements. Conclusion: The peel-off gel mask containing Spirulina platensis water extract was successfully developed with satisfactory physical quality. The 0.25% concentration formula (F1) demonstrated good stability, comparable to commercially available products.

Non-destructive in situ monitoring of photosynthetic quotient in open microalgae cultivation

2025-06-20

Yaxin Huang , Qian Zhao , Chenghu Yan +3 more | Bioresource Technology

Techno-economic analysis of Spirulina biomass production in the floating photobioreactors for fishmeal replacements

2025-06-20

Du Xiang , Chenba Zhu , Chen Hu +3 more | Journal of Cleaner Production

Optimization of enzymatic extraction of astaxanthin from Xanthophyllomyces dendrorhous using a recombinant cellulase

2025-06-20

YouKyeong Lee , Sung Ok Han , Young Jin Ko +1 more | Biotechnology and Bioprocess Engineering

One Potential Strategy for Biofuel Production: Isoprene Biosynthesis in Chlamydomonas Reinhardtii

2025-06-20

Yiqun Zhou , Kaiqi Liu | Theoretical and Natural Science

World energy is facing multiple threats. On the one hand, non-renewable energy sources such as fossil energy, which account for a large proportion, are gradually depleting, but the demand is … World energy is facing multiple threats. On the one hand, non-renewable energy sources such as fossil energy, which account for a large proportion, are gradually depleting, but the demand is still high. On the other hand, most of the energy currently used, such as oil and coal, is directly related to climate change and air pollution. Renewable biosynthetic pathways currently account for a very small proportion of energy consumption and therefore have great potential for development. Isoprene has a wide range of uses and can be used as a target product for biosynthesis. The MEP pathway of Chlamydomonas reinhardtii UPN22 can be used to synthesize this terpene compound, and there is the possibility of further improving the synthesis efficiency through the combined effects of genetic engineering and the external environment. At this stage, the characteristics of the UPN22 strain may affect the collection of isoprene products. In addition, there is a lack of real data on the entire MEP pathway, and it is impossible to confirm how these strategies will affect the synthesis of isoprene.

Chlorella sorokiniana biomass as an alternative ingredient in food (Review)

2025-06-20

Jadess Lorraine Fusio , Marlon Alejos | World Academy of Sciences Journal

MATHEMATICAL MODELLING AND ANALYSIS OF HARMFUL ALGAL BLOOM

2025-06-20

Milton Mondal | Bulletin of the Australian Mathematical Society

Growth response, proximate and bioactive compositions of Chlorella vulgaris cultured on different quantities of pure poultry manure

2025-06-20

C.C. Ikechukwu , Emmanuel Ude , C.F. Ikeogu +3 more | Journal of Aquatic Sciences

Microalgae are a diverse group of unicellular photosynthetic organisms which contain high levels of proteins, lipids, carbohydrates, pigments, minerals and vitamins in different quantities, thus, could be used as feed … Microalgae are a diverse group of unicellular photosynthetic organisms which contain high levels of proteins, lipids, carbohydrates, pigments, minerals and vitamins in different quantities, thus, could be used as feed supplement in catfish production. The study investigated growth response, proximate composition and bioactive compounds present in Chlorella vulgaris cultured on different quantities of pure poultry manure. Pure 200cl sample of C. vulgaris isolates was procured from the Limnology Unit of National Institute for Freshwater Fisheries Research (NIFFR), Niger State. Five different weights (10kg, 20kg, 30kg, 40kg and 50kg) of pure and dried poultry droppings were each soaked in 10 liters of water for two hours and inoculated with 13.33cl C. vulgaris isolates following standard procedures. Each treatment was then poured into70 litres culture plastic tanks containing 40 liters of clean water and was used for the culture of C. vulgaris. The culture systems were exposed to 10hrs daily sunlight illumination and culture duration was 16 days. Each treatment was replicated three times. Results on analysis for bioactive compounds showed that carotenoids, phenols and chlorophylls a and b were detected in the biomass of C. vulgaris signifying a good fish food source. High protein (32.41%), ash (30.33%) and metabolizable energy (262.12Kcal/g) were recorded. The treatment group containing 30kg poultry manure had the highest cell density (19.67ml/l), biomass productivity (1.82ml/l), growth rate (3.52g) and substrate consumption percentage (49.99%). This concentration provided excellent and sustainable conditions that enabled C. vulgaris multiplication. While the 10 and 20kg treatment groups recorded lower growth resources, higher concentrations of 40 and 50kg showed light penetration problems. The 30kg pure poultry manure quantity is therefore recommended for the culturing of green algae, C. vulgaris which could be used as feed supplement in the culture of Clarias gariepinus.

Functional evaluation of spirulina extract: antioxidant properties and immune regulation in aged mice models

2025-06-19

Chi‐Hsien Liu , Yi‐Chien Ho , Jingping Wang | Functional Foods in Health and Disease

Background: Spirulina platensis is a cyanobacterium rich in protein, commonly regarded as a functional food due to its exceptional nutritional profile. Among its components, phycocyanin (a water-soluble pigment-protein complex) has … Background: Spirulina platensis is a cyanobacterium rich in protein, commonly regarded as a functional food due to its exceptional nutritional profile. Among its components, phycocyanin (a water-soluble pigment-protein complex) has gained attention for its strong antioxidant, anti-inflammatory, immunoregulatory, and liver-protective properties. Both oxidative stress and chronic inflammation are key drivers of the aging process and play major roles in the development of disease, namely metabolic syndromes and neurodegenerative disorders. Although spirulina has been widely studied for its health-promoting effects, its precise role in regulating systemic redox balance and modulating age-related immune responses remains insufficiently explored. This study aims to evaluate the antioxidant and anti-inflammatory activities of spirulina extract through in vitro assays and a murine aging model. Methods: Spirulina extract was prepared via enzymatic cell wall degradation followed by fermentation. Antioxidant activity was measured in vitro through four key assays: reducing power, total antioxidant capacity, DPPH radical scavenging, and superoxide anion scavenging. Additionally, young and middle-aged mice were orally administered spirulina extract at a dose of 7 mg per day for 28 days. Blood samples were collected to assess levels of GSSG and cytokines associated with Th1/Th2 immune regulation. Results: In vitro assays showed strong antioxidant activities, particularly DPPH radical scavenging (88.58 ± 3.68%). Spirulina extract significantly increased the GSH/GSSG ratio in middle-aged mice, indicating improved antioxidant status, while no changes were seen in young mice. Additionally, spirulina upregulated Th1 cytokines and downregulated Th2 cytokines in middle-aged mice, with significant reductions in IL-6 and -10. Spirulina extract demonstrated potent antioxidant and immunomodulatory effects, alleviating oxidative stress and correcting Th1/Th2 imbalance during aging. These results support its potential as a supplement for promoting healthy aging in the mouse model. Conclusion: Combining cell-based experiments with an aging mouse model, this research reveals new perspectives on spirulina’s impact on maintaining redox balance and modulating immune function. The results indicate that spirulina extract could be a beneficial supplement for addressing oxidative stress and immune aging during midlife. Further clinical studies are warranted to explore its potential as a functional food or nutraceutical aimed at reducing age-associated immune dysfunction and inflammation. Keywords: spirulina extract, antioxidant activity, cytokine, immune regulation.

Co-culture of microalgae and bacteria for the production of bioactive compounds

2025-06-19

Luiz Gonzaga de França Lopes , Raquel Cavalcante Soares , Robério Mires de Freitas +5 more | Annals of Microbiology

Rewiring photosynthetic carbon flow: Engineered cyanobacterial factories for sustainable carbohydrate production and carbon-negative biomanufacturing

2025-06-19

Xinyi Bai , Guangbao Zhang , Libo Xu +3 more | Bioresource Technology

An overall study on efficient Cr (VI) adsorbents for improving of the application value of Chlorella pyrenoidosa

2025-06-19

Yitong Wang , Liang-Yi Zhang , Le‐Le Kang +7 more | Ecotoxicology and Environmental Safety

Growth performance and lipid profile of psychrophilic strains Chlorella sp., Haematococcus lacustris, Scenedesmus sp. and Chlamydomonas reinhardtii under different synthetic media and light irradiation

2025-06-19

Paolina Scarponi , F. Sala , Daniela Sala +3 more | Biomass and Bioenergy

Enhancing efficiency and sustainability in wastewater treatment via non-aerated ARTP-mutagenized Chlorella-Acinetobacter symbiosis

2025-06-19

Xin Sun , Qiqi Zhang , Hongwei Li +3 more | Chemical Engineering Journal

Sequential Optimization of Biomass and Lutein Production by Dictyosphaerium sp. HT3

2025-06-19

Mai Thi Dang , Thu Uyen T. Bui , Duong Thi Ba +5 more | Asia-Pacific Journal of Chemical Engineering

ABSTRACT Microalgae‐synthesized lutein has been received considerable attention in scientific research community. Although several microalgae have recently identified as hyper‐lutein accumulators, further discovery of new microalgae strain owning an outstanding … ABSTRACT Microalgae‐synthesized lutein has been received considerable attention in scientific research community. Although several microalgae have recently identified as hyper‐lutein accumulators, further discovery of new microalgae strain owning an outstanding capability in lutein production is necessarily for diversification of large‐scale cultivations. In this work, critical factors, for example, carbon, nitrogen source, and light intensity affecting growth and lutein accumulation by a newly isolate microalgal Dictyosphaerium sp. HT3, were investigated. In particular, biomass and lutein production by Dictyosphaerium sp. HT3 under mixotrophic cultivation were optimized via a sequential process of single‐factor investigation, followed by response surface methodology. The obtained results displayed that Dictyosphaerium sp. HT3 achieved the optimal growth under mixotrophic cultivation in BG‐11 medium with glucose of 8.6–9.2 g/L, sodium nitrate of 1.63–2.1 g/L, light intensity of 240–290 μmol photons m −2 s −1 , aeration rate of 0.1 vvm, and 25°C, achieving the maximal dry biomass of 4.25–4.67 g/L and the highest lutein content of 17.06–18.95 mg/g. The one‐stage cultivation and optimization developed in this study are superior to two‐stage processes for microalgal lutein production reported in the literature. Our trial investigation demonstrated that Dictyosphaerium sp. HT3 holds a promising potential for scaling‐up production of both biomass and lutein via mixotrophic cultivation.

Efficient secretory production of recombinant proteins in microalgae using an exogenous signal peptide

2025-06-18

Trang Thi Le , Quynh‐Giao Tran , Su-Bin Park +7 more | Frontiers in Microbiology

Microalgae are promising platforms for recombinant protein production due to their scalability, rapid growth, safety, and sustainability. One strategy to reduce downstream processing costs is to secrete recombinant proteins directly … Microalgae are promising platforms for recombinant protein production due to their scalability, rapid growth, safety, and sustainability. One strategy to reduce downstream processing costs is to secrete recombinant proteins directly into the culture medium, facilitated by signal peptides (SPs). However, the limited availability of effective SPs has hindered broader applications of this approach in microalgae. In this study, we identified a novel SP from a highly secreted protein of approximately 17 kDa in the culture medium of Chlorella sp. HS2. N-terminal sequencing via Edman degradation enabled identification of the corresponding gene, which encodes a hypothetical protein we designated MAPS (Most Abundant Protein in the Secretome). Bioinformatic analyses revealed a functional SP with features consistent with efficient secretory activity. To evaluate its utility, we generated transgenic Chlamydomonas reinhardtii strains expressing mCherry fused to this Chlorella sp. HS2-derived SP. Compared to two commonly used endogenous SPs from C. reinhardtii , the HS2-SP significantly enhanced mCherry secretion, achieving approximately two-fold higher levels in the culture medium. These findings highlight the potential of HS2-SP in improving recombinant protein secretion in C. reinhardtii , thereby supporting its application in algal biotechnology and industrial protein production.

Life cycle environmental impact assessment of microalgae biodiesel derived from different processes

2025-06-18

Yunyun Liu , Rundong Xia , Yujing Wang +2 more | Industrial Crops and Products

Ảnh hưởng của chitosan đến hiệu suất thu hồi sinh khối và khả năng bảo vệ chất màu vi tảo Nannochloropsis sp. trong quá trình bảo quản

2025-06-18

Phạm Thị Đan Phượng , Kiều Oanh Hà , Vĩ Hích Trần | Tạp chí Khoa học - Công nghệ Thủy Sản Trường Đại học Nha Trang

Nghiên cứu này đánh giá hiệu quả của phương pháp keo tụ sinh học sử dụng chitosan trong việc thu hồi sinh khối Nannochloropsis sp. và hiệu quả bảo quản … Nghiên cứu này đánh giá hiệu quả của phương pháp keo tụ sinh học sử dụng chitosan trong việc thu hồi sinh khối Nannochloropsis sp. và hiệu quả bảo quản sắc tố trong sinh khối vi tảo sau thu hoạch. Quá trình thu hồi sinh khối được thực hiện bằng chitosan (khối lượng phân tử ~520 kDa, nồng độ 60 ppm) và lọc qua vải lọc. Kết quả cho thấy hiệu suất thu hồi sinh khối đạt khoảng 88%, với hiệu suất thu hồi chlorophyll-a và carotenoid lần lượt là khoảng 95% và 89%. Sinh khối vi tảo đậm đặc sau đó được bổ sung 0,1% vitamin C và bảo quản ở 4±2°C. Sau 10 tuần bảo quản, tỷ lệ tổn thất carotenoid và chlorophyll-a lần lượt là khoảng 7% và 5%. Các kết quả này cho thấy tiềm năng của phương pháp thu hoạch và bảo quản được đề xuất trong việc duy trì chất lượng sinh khối Nannochloropsis sp. giàu sắc tố. Từ khóa: Chitosan, Nannochloropsis sp., hiệu suất thu hồi sinh khối, chlorophyll-a, carotenoid. ABSTRACT This study evaluates the effectiveness of chitosan-based bioflocculation for harvesting Nannochloropsis sp. biomass and the efficiency of pigment preservation in the microalgal biomass during storage. The microalgal biomass harvesting process was carried out using chitosan (molecular weight ~520 kDa, concentration 60 ppm) followed by cloth filtration. The results showed a biomass recovery efficiency of approximately 88%, while the recovery efficiencies of chlorophyll-a and carotenoids were approximately 95% and 89%, respectively. The concentrated microalgal biomass was supplemented with 0.1% vitamin C and stored at 4±2°C. After 10 weeks of storage, the loss rates of carotenoids and chlorophyll-a were approximately 7% and 5%, respectively. These results indicate the potential of the proposed harvesting and preservation method for maintaining the quality of pigment-rich Nannochloropsis sp. biomass. Keywords: Chitosan, Nannochloropsis sp., biomass recovery efficiency, chlorophyll-a, carotenoid.

Progress and prospects in metabolic engineering approaches for isoprenoid biosynthesis in microalgae

2025-06-18

Sonia Mohamadnia , Borja Valverde‐Pérez , Omid Tavakoli +1 more | Biotechnology for Biofuels and Bioproducts

Abstract Isoprenoids constitute a large and various number of bio-compounds, with many profitable applications in pharmaceutical, nutraceutical, and industrial fields. The complexity of isoprenoid molecules leads to a challenging, expensive, … Abstract Isoprenoids constitute a large and various number of bio-compounds, with many profitable applications in pharmaceutical, nutraceutical, and industrial fields. The complexity of isoprenoid molecules leads to a challenging, expensive, and environmentally unfriendly chemical synthesis of these metabolites. In addition, the awareness and desire of many consumers for products generated by natural microbial processes has increased recently. Metabolic engineering tools and synthetic biology strategies have been used as a means for the enhancement and optimization of the natural isoprenoid biosynthetic pathways of wild strains. Microalgae as production organisms have been manipulated for the bioproduction of diverse isoprenoids. Particularly when cultivated in unsuitable conditions (such as wastewater, unbalanced nutritional sources, and distinct environmental conditions), microalgae can adjust their metabolic pathways and generate compounds with significant technological potential. Several metabolic engineering approaches have been developed, modifying the metabolic pathways in microalgae to redirect the flow of carbon toward isoprenoid biosynthesis, including pathway engineering, strain improvement, and synthetic biology. In this review, some beneficial features of these high-value metabolites are summarized. Besides, recent advancements in metabolic engineering approaches for the biosynthesis of isoprenoids are discussed in detail. At last, the viewpoints and challenges for the biosynthesis of novel compositions with isoprene units in the microalgae are also included.

Algae- a self-sustaining closed loop ecosystem as a resilient solution to future energy needs

2025-06-18

Shreya Sharma , Avinash Kshitij | International Journal of Green Energy

Microalgae biomass as a sustainable solution for food security: Advances in biotechnology and their role in achieving Sustainable Development Goals

2025-06-18

Maricarmen Iñiguez‐Moreno , Georgia María González-Meza , Rafael G. Araújo +2 more | Bioresource Technology Reports

Production of protein biomass from Chlorella vulgaris using foliar fertilizer nutrients

2025-06-18

Yesica Jhoana Benavides Escobar , John Alexander Muelas Calambas , Iván Ramírez +3 more | Cleaner Waste Systems

Original article comparative nutrient and sensory analysis of eight different commercial Chlorella powders

2025-06-18

Felix Melcher , Tillmann Peest , Darío Garay +7 more | Frontiers in Food Science and Technology

A growing global population and climate change challenge conventional agriculture and global food safety. Microalgae are an emerging sustainable nutrient food resource, increasingly regarded as an important component for the … A growing global population and climate change challenge conventional agriculture and global food safety. Microalgae are an emerging sustainable nutrient food resource, increasingly regarded as an important component for the human diet. The chlorophyte Chlorella sp. is regulated and commercialized for food applications. Commercial Chlorella preparations are either produced by heterotrophic fermentation or photoautotrophic cultivation in bioreactors or outdoor ponds. Products can differ significantly with regard to taxonomy of the production strain, changed genetic properties due to strain development, cultivation conditions, and downstream biomass processing methods. Notably, heterotrophic strains may be adapted to generate little or no photosynthetic pigments, resulting in yellow or white variant. In this study, eight different commercial Chlorella products from different EU suppliers were analyzed and compared regarding identity of the production strain, macro-and micronutrient profiles, sensory properties, as well as microbial load. The production processes featured different cultivation methods, production strains, genetic variants (yellow and white) and downstream processing methods. Data indicates significant variations between the Chlorella products. White and yellow Chlorella products showed different protein and taste profiles compared to green, photosynthetically competent wild type strains. We confirmed relatively high and stable protein concentrations but could detect variations in sugar and specifically lipid and vitamin profiles depending on strain, cultivation and downstream processing methods. The microbial load varied strongly between closed and open cultivation systems but was compliant with legislative (EFSA) specifications for all samples. The comparative nutrient- and sensory data set presented in this study will aid in selecting algae products for the development of innovative foods, thereby accelerating adoption and differentiation of algae food products.

Impact of surplus P with N and S modulation for enhanced microalgal lipid productivity in closed reactor system

2025-06-18

Diptymayee Padhi , Manoranjan Nayak | Chemosphere

Fabrication and characterization of microalgae-based additive ethylene vinyl acetate composites as sustainable bioplastics

2025-06-17

Y.-K. Yeh , Yi-Ting Wei , Jo‐Shu Chang +1 more | International Journal of Biological Macromolecules

Microalgae as a Sustainable Alternative to Palm Oil: Fatty Acid Profiles under Photoautotrophic and Heterotrophic Growth

2025-06-17

Karolína Štěrbová , Kateřina Bišová , Jiří Masojídek | Research Square (Research Square)

<title>Abstract</title> Palm oil is the world's most widely used vegetable oil, with a sizeable impact on the environment. As an alternative, microalgae are considered oil producers since they produce a … <title>Abstract</title> Palm oil is the world's most widely used vegetable oil, with a sizeable impact on the environment. As an alternative, microalgae are considered oil producers since they produce a variety of fatty acids (FA) depending on growth conditions. A collection of ten microalgae strains naturally producing oils similar in composition to palm oil was selected, and the effects of cultivation regime and varying light intensity on their growth and fatty acid (FA) production and composition were analysed. To achieve high biomass density as well as total fatty acid (TFA) content, the optimum irradiance of 400 µmol photons m− 2 s− 1 in a photoautotrophic regime was determined for most of the strains. The growth rates of <italic>Scenedesmus</italic> and <italic>Desmodesmus</italic> strains in general were approximately twice as high as <italic>Chlamydomonas</italic>. The highest TFA content was found in <italic>S. obliquus</italic> CCALA 455 and <italic>D. subspicatus</italic> CCALA 467 grown photoautotrophically reaching the values of about 66% and 58% of their dry weight, respectively. Moreover, the content of palmitic (PA), oleic (OA) and linoleic acid (LA) of about 39%, 30% and 14% of TFA, respectively, determined in <italic>D. subspicatus</italic> CCALA 467 was closest to that in palm oil (44% of PA, 39% of OA and 10% of LA). Eight of the ten microalgae strains were capable of heterotrophic growth although their production under this regime has not been considered as suitable in terms of TFA and individual FA content.

Advanced Biocatalytic Processes for the Conversion of Renewable Feedstocks into High-Value Oleochemicals

2025-06-17

João H. C. Wancura , Eliane Pereira Cipolatti , Evelin A. Manoel +6 more | Catalysts

Oleochemicals, which are obtained from vegetable and animal fats and oils, have become indispensable in the food, cosmetics, pharmaceutical and biofuel industries. Traditionally, they are synthesized using chemical catalysts, a … Oleochemicals, which are obtained from vegetable and animal fats and oils, have become indispensable in the food, cosmetics, pharmaceutical and biofuel industries. Traditionally, they are synthesized using chemical catalysts, a process that is often associated with high energy requirements and a considerable environmental impact. Biocatalysis, using enzymes such as lipases, has emerged as a transformative alternative that offers high specificity, environmental friendliness and cost-efficiency. This review comprehensively examines the current state of biocatalysis for oleochemical synthesis, highlighting key reactions such as esterification and transesterification and their integration into industrial processes. A bibliometric analysis uncovers global trends and collaborations, while case studies illustrate cost efficiency and scalability. The article outlines recommendations and future research directions to advance biocatalytic processes. This review is intended to be an important resource for researchers and industries transitioning to sustainable oleochemical production.