Hydrogen (H2) is a renewable, abundant, and nonpolluting source of energy. Photosynthetic organisms capture sunlight very efficiently and convert it into organic molecules. Cyanobacteria produce H2 ...by breaking down organic compounds and water. In this study, biological H2 was produced from various strains of cyanobacteria. Moreover, H2 accumulation by Synechocystis sp. PCC 6803 was as high as 0.037 μmol/mg Chl/h within 120 h in the dark. The wild-type, filamentous, non-heterocystous cyanobacterium Desertifilum sp. IPPAS B-1220 was found to produce a maximum of 0.229 μmol/mg Chl/h in the gas phase within 166 h in the light, which was on par with the maximum yield reported in the literature. DCMU at 10 μM increased H2 production by Desertifilum sp. IPPAS B-1220 by 1.5-fold to 0.348 μmol H2/mg Chl/h. This is the first report on the capability of Desertifilum cyanobacterium to produce H2.
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•Four non-heterocystous cyanobacterial strains were investigated for H2 production.•Best H2 accumulation was observed with Synechocystis sp. PCC 6803 in the dark.•Photoautotrophic H2 production yield of Desertifilum sp. IPPAS B-1220 was 0.229 μmol/mg Chl/h.•H2 yield was increased with the Desertifilum sp. IPPAS B-1220 by 1.5-fold in the presence of DCMU.
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•The optimal concentration of CO2 for cultivation of cyanobacterial strains was determined.•The optimal concentration of wastewater for cultivation of cyanobacteria was ...determined.•The fatty acid composition of lipids was studied.•The yield of dry biomass and methyl esters of Cyanobacterium sp. IPPAS B-1200 strain was determined.
Current fresh water and energy shortage determines the need to study the possibilities of using living objects in bioenergy and environmental purification technologies. The development of waste-free technologies allows waste recycling, which saves raw materials and energy, in turn, reducing waste generation. The effect of different carbon dioxide concentrations and wastewater from households on the growth of cyanobacteria was studied in order to determine their capabilities in the purification processes. It was found that the optimal CO2 concentration for the cultivation of cyanobacteria Cyanobacterium sp. IPPAS B-1200 and Desertifilum sp. IPPAS B-1220 was 10 %, and for the Cyanobacterium aponinum IPPAS B-1201 – 5%. It was revealed that the cultivation of the cyanobacterium Cyanobacterium sp. IPPASB-1200 on wastewater from the water storage reduces the concentration of organic pollutants and, accordingly, improves the physicochemical properties of water. The cleaning percentage for selected pollutants was 68–100 %. It was shown that the most optimal ratio of wastewater to nutrient media for cyanobacteria cultivation were 25:75 and 50:50. The lipid content (%/dry weight) in the biomass of the studied strains of cyanobacteria ranges from 15 to 22% after cultivation in wastewater. It was determined that the strains of Cyanobacterium genus were the most suitable for the production of biodiesel according to their fatty acids composition. It was determined that lipids were composed of only saturated and monounsaturated fatty acids. As a result of the studies, the optimal conditions for the growth of Cyanobacterium sp. IPPAS B-1200 were determined. This microorganism has a good potential to produce biodiesel as a producer of saturated and monounsaturated middle-chain-length fatty acids.
Biomass of high-yielding strains of phototrophic microorganisms actively accumulating lipids is a promising non-traditional raw material for bioenergy including the production of biodiesel. In this ...study, we present results of searching for new strains of microalgae-producers of lipids from hot springs. Within the framework of research, the primary screening of water for the presence of lipid - accumulative microalgae was carried out with the help of qualitative reaction with lipid-specific dyes, as well as 5 axenic isolates of microalgae with stable growth were identified in the laboratory and their productivity and fatty acid composition were studied. The isolated strains were identified as Chlorella vulgaris sp-1, Ankistrodesmus sp-21, Scеnеdеsmus obliquus sp-21, Chlorella pyrenoidosa sp-13 and Chlamydomonas sp-22. The obtained data showed that the isolated strains determined by biomass in the range 1.3 g/l to 1.81 g/l. As a result of the research, it was established that the highest content of lipids was observed in the strains Chlorella vulgaris sp-1 and Scеnеdеsmus obliquus sp-21, which is 28.7 and 29.8% of the cell dry weight, respectively. The analysis of the fatty acid composition of the cells showed that the largest mass fraction of saturated and monounsaturated fatty acids was found in strain Scеnеdеsmus obliquus sp-21 - 61.9%. In the result, Scеnеdеsmus obliquus sp-21 strain isolated from thermal sources was selected as a promising candidate for biodiesel production.
•16 species of microalgae were identified in hot springs, Kazakhstan.•Scеnеdеsmus obliquus sp-21 accumulated 29.8% of lipids in the biomass.•Fatty acid composition of total lipids was suitable for biodiesel production.•Scеnеdеsmus obliquus sp-21 is promising candidate for biodiesel production.
Five axenic cultures of microalgae were isolated from the wastewater of Almaty city and identified as Chlorella vulgaris strain № 1, Chlorella sp. strain № 3, Scenedesmus obliquus, Phormidium ...foveolarum and Lyngbya limnetica. Among these strains, C. vulgaris strain № 1 was characterized by the maximum growth rate and the highest productivity. Mass cultivation of this strain in wastewater resulted in accumulation of 5 × 107 cells per ml in 16 days, and in the removal of ∼95% of pollutants from water. Cells of C. vulgaris consisted of ∼35% proteins, 29% carbohydrates, 30% lipids, and 6% ash, as calculated on a dry weight basis. The major fatty-acids of C. vulgaris were represented by palmitic, cis-7,10-hexadecenoic acid, linoleic, and α-linolenic acids. Culturing in wastewater decreased the unsaturation index of FAs. Thus, C. vulgaris cells are suitable for both waste water purification and accumulation of biomass for further biodiesel production.
•16 species of microalgae were identified in wastewaters, Almaty, Kazakhstan.•Chlorella vulgaris purified wastewater and accumulated 30% of lipids in the biomass.•Fatty acid composition of total lipids was suitable for biodiesel production.•Culturing in wastewater decreases the unsaturation index of fatty acids.•C. vulgaris is suitable for wastewater purification and biodiesel production.
Hydrogen is a promising alternative to fossil fuel for a source of clean energy due to its high energy content. Some strains of phototrophic microorganisms are known as important object of scientific ...research and they are being explored to raise biohydrogen (BioH2) yield. BioH2 is still not commonly used in industrial area because of the low biomass yield and valuable down streaming process. This article deals with the methods of the hydrogen production with the help of two large groups of phototrophic microorganisms – microalgae and cyanobacteria. Microalgal hydrogen is environmentally friendly alternative to conventional fossil fuels. Algal biomass has been considered as an attractive raw source for hydrogen production. Genetic modified strains of cyanobacteria are used as a perspective object for obtaining hydrogen. The modern photobioreactors and outdoor air systems have been used to obtain the biomass used for hydrogen production. At present time a variety of immobilization matrices and methods are being examined for their suitability to make immobilized H2 producers.
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•Hydrogen production from microalgae and cyanobacteria.•Mechanisms of biohydrogen metabolism.•Bioreactors for biohydrogen production process.•Enzymes of biohydrogen production.
Here, we report the draft genome of the filamentous cyanobacterium Desertifilum sp. strain IPPAS B-1220, isolated from Lake Shar-Nuur, Mongolia. The genome of 6.1 Mb codes for 5,113 genes. Genome ...mining revealed 10 clusters for the synthesis of bioactive compounds (nonribosomal peptides, polyketides, bacteriocins, and lantipeptides) with potential biotechnological or medical importance.
Due to the depletion and increasing cost of fossil fuels, the production of cyanobacteria-based hydrogen as eco-friendly and renewable energy for the future seems promising. The paper describes the ...current state of research in the field of hydrogen yield by cyanobacteria. The use of cyanobacteria as potential producers of hydrogen is particularly relevant and beneficial as they form hydrogen from water as a result of solar energy conversion. However, production is a complex biotechnological process, and the main obstacle is the low ability of cyanobacteria to produce hydrogen. The prospects for the development of cyanobacterium-based hydrogen energy can be improved by a complex approach of increasing hydrogen productivity by cyanobacteria cells. First of all, it is the achievement of genetic engineering, the construction of genetic mutants of cyanobacteria with great potential in hydrogen production, followed by a correctly chosen metabolic approach to increase its yield and the development of innovative methods of their cultivation. Thus, the widespread adoption of this technology requires additional R&D with large investments.
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•Critically reviews the cyanobacterial hydrogen production.•Bioprocesses of hydrogen formation by cyanobacterial cells.•Genetic and metabolic engineering approaches towards H2 production from cyanobacteria.•Recent technological progress towards cyanobacteria-based hydrogen production.
A limited supply of oil prompts the search for non-traditional energy sources to replace traditional ones. This makes hydrogen gas an appealing alternative source. Photosynthetic organisms capture ...sunlight very efficiently and convert it into organic molecules. A promising wild strain was isolated for the first time, from the rice paddies of Kazakhstan (Kyzylorda and Almaty regions), which can be considered as one of the most active hydrogen producers compared to the literature. The result showed that among the 13 isolated and collection cyanobacterial strains, Synechocystis sp. S-1 is the most active H2 producer (2.35 μmol H2 mg−1Chl a h−1) in the light. In contrast, the wild-type cyanobacterium Anabaena variabilis A-1 had higher productivity, nitrogenase activity, and a stronger capacity to produce hydrogen in the dark (8.67 μmol H2 mg−1Chl a h−1), which matched the maximum yield obtained in the research. The metabolic modulation performed significantly increased hydrogen production. The highest photohydrogen production rate was observed in cells incubated with 25 μmol HEPES and 50 μmol sodium bicarbonate (NaHCO3).
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•Novel cyanobacterial strains were isolated from rice paddies and identified.•Сyanobacterial strains have been screened for productivity.•Hydrogen production by cyanobacterial strains was examined.•Strains were adapted to produce H2 optimizing their physiological properties.
The continued search and urgent need for renewable fuel sources have necessitated the exploration of microalgae to identify relevant species for making biofuels. The aim of the study was ...bioprospecting and screening native microalgae strains from freshwater habitats of the Almaty region, Kazakhstan, to assess the potential for producing biofuel. The studied strains demonstrated simultaneous biomass productivity, lipid productivity, suitable fatty acid composition, and biodiesel properties. The sequence analysis of the ribosomal DNA internal transcribed spacer partial region and ribulose-bisphosphate carboxylase gene (rbcL) led to the identification of five microalgae: Monoraphidium griffithii ZBD-01, Nephrochlamys subsolitaria ZBD-02, Ankistrodesmus falcatus ZBD-03, Parachlorella kessleri ZBD-04, and Desmodesmus pannonicus ZBD-05. P. kessleri had the highest biomass production (1.42 ± 0.08 g L−1 day−1), lipid productivity (29 ± 1.2 g L−1day−1), and C16–C18 fatty acid contents (90%), followed by A. falcatus and M. griffithi. Gas chromatography/mass spectrometry analysis indicated that the dominant fatty acids in these strains were palmitic, stearic, and oleic acids. The calculated biodiesel properties of P. kessleri and A. falcatus based on fatty acid methyl esters (FAME) profiles showed relatively good fuel properties (cetane numbers - 48 and 50; iodine and saponification values - 83.4 and 103.6 g I₂/100 g oil, 260.8 and 199.5 mg KOH g−1), which correlate well with. Our results suggest that P. kessleri and A. falcatus are promising strains for biodiesel production due to their high lipid productivity, fatty acid profile with relatively high content of oleic acid, and suitable biodiesel properties. The isolated native species of microalgae from natural freshwater bodies of the Almaty region present opportunities for further exploitation for the sustainable production of biomass and biodiesel.
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·New native strains of green microalgae were isolated and identified.·Fatty acids composition of microalgae strains was investigated.·Microalgae strains found enriched with saturated fatty acids (C16:0 and C18:0).·These strains are the best candidate for application in biofuel.
Increasing awareness of the harmful effects of synthetic colorants has led consumers to favor the use of natural alternatives such as plant or microbial pigments in food and cosmetics. Cyanobacteria ...are a rich source of many natural biopigments that are of high commercial value. In the market, bio-based pigments are usually sold as extracts to reduce purification costs. Various cell disruption methods are used for pigment extraction, such as sonication, homogenization, high pressure, supercritical CO2 extraction, enzymatic extraction, as well as other promising novel extraction methods that make the production of cyanobacterial pigments economically viable. In addition, a continuous cultivation system is considered the most suitable cultivation mode for large-scale biomass production. However, a major limitation in the large-scale production of cyanobacterial pigments is the installation and operation costs. Thus, basic and applied research is still needed to overcome such limitations and enable cyanobacteria to enter the global market. This review focuses on various cyanobacterial pigments, their applications, and current biotechnological approaches to increase the production of biopigments for their potential use in the pharmaceutical, food, and cosmetic industries. The current state of production technologies based on either open pond systems or closed photobioreactors was compared. The potential of scientific and technological advances to increase yield and reduce production costs of cyanobacteria biomass-based pigments was also discussed.
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•Cyanobacterial pigments (CPs) are safe and eco-friendly in comparison to synthetic ones.•CPs have commercial value due to their brilliant colors, antioxidant property and health promoting factors.•Various biotechnological approaches for optimizing CPs are considered.•The main extraction methodologies for each pigment are discussed and evaluated.
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