title: Isolation and characterization of Aurantiochytrium species: high docosahexaenoic acid (DHA) production by the newly isolated microalga, Aurantiochytrium sp. SD116.
abstract: A heterotrophic microalga, strain SD116, with the ability to produce high concentrations of docosahexaenoic acid (DHA, C22:6n-3) was isolated from Shuidong Bay, Guangdong Province, China. Nucleotide sequence analysis of the 18S rDNA of SD116 showed that the strain has a close phylogenetic relationship to Aurantiochytrium species. The highest rates for growth and DHA accumulation for SD116 were obtained in 6.0% glucose, 2.0% yeast extract, and 50% artificial seawater (ASW) at a pH of 7 at 28°C. The maximum total lipid content reached 56.3% of the dry cell weight (DCW), and the maximum DHA content accounted for 50.9% of the total fatty acid (TFA) content. It was further found that urea may be a potential nitrogen source for industrial fermentation because of its cheap price and ability to induce a relatively high biomass and lipid production capacity. Using 5 L fermenters, the DCW, total lipid content, and DHA yield were found to be 70.43 g L(-1), 71.09% of the DCW, and 17.42 g L(-1) (34.79% of the TFA), respectively. The results show that Aurantiochytrium sp. SD116 is a promising candidate for commercial DHA production and could be useful for the synthesis of biomass-related products.
authors.affiliation: Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, P. R. China.
authors.forename: Mang
authors.initials: M
authors.lastname: Gao
authors.forename: Xiaojin
authors.initials: X
authors.lastname: Song
authors.forename: Yingang
authors.initials: Y
authors.lastname: Feng
authors.forename: Wenli
authors.initials: W
authors.lastname: Li
authors.forename: Qiu
authors.initials: Q
authors.lastname: Cui
mesh_terms: D018533:Biomass; D004281:Docosahexaenoic Acids / Q000032:analysis / Q000096:biosynthesis* / Q000737:chemistry; D058009:Stramenopiles / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D004281:Docosahexaenoic Acids