ARS | Publication request: Identification of naturally isolated southern Louisiana's algal strains and the effect of higher Co2 content on fatty acid profiles for biodiesel production

Submitted to: Journal of Industrial Microbiology and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 25, 2012
Publication Date: October 28, 2012
Citation: Moreno, R., Aita, G.M., Madsen, L., Guitierrez, D.L., Yao, S., Hurlburt, B.K., Brashear, S.S. 2012. Identification of naturally isolated southern Louisiana's algal strains and the effect of higher Co2 content on fatty acid profiles for biodiesel production. Journal of Industrial Microbiology and Biotechnology. 88:948-957.

Interpretive Summary: Microalgae hold promise as a source of third generation biodiesel production. In this study, microalgae were collected from various sources in southern Louisiana. They were identified by microscopy and molecular biology as cyanobacteria, diatoms, and green algae. The fatty acids they produce are important for biodiesel production, and these were characterized under different growth conditions.

Technical Abstract: Four naturally isolated microalgae were evaluated for their potential use in the production of biodiesel, and were identified using genomic DNA, and 16S or 18S rRNA gene amplification followed by sequencing. High correlation was found with known nucleotide sequence identities at 98 % with Sellaphora pupula, and 99 % with Synechococcus sp., Chlorella sorokiniana, Scenedesmus abundans, and Chlorella vulgaris (control). The fatty acid profiles of these organisms changed when using 5 % CO2 aeration. Total fatty acids (TFA) decreased from 20.63 to 17.62, 54.83 to 24.4, and 29.82 to 25.07 g kg-1 dry biomass in Synechococcus sp., Sellaphora pupula and Chlorella sorokiniana, respectively. TFA increased from 14.14 to 31.49 and 15.14 to 47.52 g kg-1 dry biomass in Scenedesmus abundans and Chlorella vulgaris (control), respectively. Chlorella sorokiniana, with a lower C18:3 and the highest biomass yield, was found to be the best candidate of all the strains evaluated for biodiesel production.