Light stress after heterotrophic cultivation enhances lutein and biofuel production from a novel algal strain Scenedesmus obliquus ABC-009

The mutagenesis is an emerging strategy for screening microalgal candidates for CO2 biofixation and biomass production. In this study, by 96-well microplates-UV mutagenesis, a mutant stemmed from Scenedesmus obliquus was screened and named as SDEC-1M. To characterize SDEC-1M, it was cultivated under air and high level CO2 (15% v/v), and its parental strain (PS) was considered as control. Growth characterizations showed that SDEC-1M grew best in high level CO2. It indicated that the mutant had high CO2 tolerance (HCT) and growth potential under high level CO2. Richer total carbohydrate content (37.26%) and lipid content (24.80%) demonstrated that, compared to its parental strain, SDEC-1M was apt to synthesize energy storage materials, especially under high CO2 level. Meanwhile, the highest light conversion efficiency (approximately 18 %) was also obtained. Thus, the highest overall biomass productivities were achieved in SDEC-1M under high level CO2, largely attributed to that the highest productivities of total lipid, total carbohydrate, and crude protein were also achieved in the meantime. By modified UV, therefore, mutagenized SDEC-1M was the better candidate for CO2 biofixation and biofuel production than its parental strain.

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Metagenome Survey of a Multispecies and Alga-Associated Biofilm Revealed Key Elements of Bacterial-Algal Interactions in Photobioreactors

Applied and Environmental Microbiology ◽

10.1128/aem.01641-13 ◽

2013 ◽

Vol 79 (20) ◽

pp. 6196-6206 ◽

Cited By ~ 63

Author(s):

Ines Krohn-Molt ◽

Bernd Wemheuer ◽

Malik Alawi ◽

Anja Poehlein ◽

Simon Güllert ◽

...

Keyword(s):

Bacterial Species ◽

Scenedesmus Obliquus ◽

Maximum Size ◽

Bacterial Biofilm ◽

Biofuel Production ◽

Associated Bacteria ◽

Content Type ◽

Rrna Phylogeny ◽

Biofilm Bacteria ◽

Algal Productivity

ABSTRACTPhotobioreactors (PBRs) are very attractive for sunlight-driven production of biofuels and capturing of anthropogenic CO2. One major problem associated with PBRs however, is that the bacteria usually associated with microalgae in nonaxenic cultures can lead to biofouling and thereby affect algal productivity. Here, we report on a phylogenetic, metagenome, and functional analysis of a mixed-species bacterial biofilm associated with the microalgaeChlorella vulgarisandScenedesmus obliquusin a PBR. The biofilm diversity and population dynamics were examined through 16S rRNA phylogeny. Overall, the diversity was rather limited, with approximately 30 bacterial species associated with the algae. The majority of the observed microorganisms were affiliated withAlphaproteobacteria,Betaproteobacteria, andBacteroidetes. A combined approach of sequencing via GS FLX Titanium from Roche and HiSeq 2000 from Illumina resulted in the overall production of 350 Mbp of sequenced DNA, 165 Mbp of which was assembled in larger contigs with a maximum size of 0.2 Mbp. A KEGG pathway analysis suggested high metabolic diversity with respect to the use of polymers and aromatic and nonaromatic compounds. Genes associated with the biosynthesis of essential B vitamins were highly redundant and functional. Moreover, a relatively high number of predicted and functional lipase and esterase genes indicated that the alga-associated bacteria are possibly a major sink for lipids and fatty acids produced by the microalgae. This is the first metagenome study of microalga- and PBR-associated biofilm bacteria, and it gives new clues for improved biofuel production in PBRs.

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Optimization of Suitable Eco-Friendly Technology for Bioremediation of Textile Wastewaters

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.k2563.0981119 ◽

2019 ◽

Vol 8 (11) ◽

pp. 3482-3486

Keyword(s):

Waste Water ◽

Scenedesmus Obliquus ◽

Sewage Treatment ◽

Chlorella Pyrenoidosa ◽

Biofuel Production ◽

Human Beings ◽

Effective Removal ◽

Clean Environment ◽

New Treatment ◽

Textile Wastewaters

Water is one of the major products of nature used enormously by human beings and it is not unnatural that any growing community generates enormous waste water or sewage. As a clean environment is a prerequisite for a healthy living in any urban settlement, proper treatment and safe disposal of sewage call for prime attention. Untreated waste water can cause pollution of surface and ground waters. Many new developments in the field of sewage treatment are eventually taking place. These developments include improvements for more effective removal of pollutants and new treatment processes capable of removing pollutants not ordinarily removed by conventional methods. Three types of textile wastewaters (Acid Yellow dye, Acid orange dye and Basic pink dye) has been used for wastewater treatment and microalgal (Chlorella pyrenoidosa and Scenedesmus obliquus) biofuel production. Nitrogen content in textile wastewaters is very less, hence urea is used as nitrogen source in wastewater. Discharge of untreated domestic and industrial wastewater into aquatic bodies is posing a serious eutrophication threat, leading to a slow degradation of the water resources. A number of physical, chemical and biological methods have been developed for the treatment of wastewaters; among these, the use of microalgae is considered as a more eco-friendly and economical approaches.

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