高产DHA破囊壶菌Aurantiochytrium sp.PKU#SW7诱变株的筛选

Screening of high docosahexanoic acid yield mutants of Aurantiochytrium sp. PKU#SW7

【目的】对野生菌株Aurantiochytrium sp.PKU#SW7诱变育种,筛选高产DHA突变株。【方法】采用UV诱变和化学药物胁迫筛选方式,以菌株的生物量、油脂产量、DHA产量作为筛选指标,获得高产DHA突变株。【结果】经鉴定获得一株DHA高产突变株PKU#PM003,该菌株传代4次后仍保持较好的遗传稳定性。摇瓶发酵后,PKU#PM003生物量产量高达6.62 g/L,比原始菌株5.95 g/L提高了11.26%,脂肪酸含量高达4.01 g/L,比原始菌株3.18 g/L提高了26.1%,DHA在脂肪酸中所占比例由29.97%增加到33.43%,产量提高了41.01%,油脂突变效果显著。【结论】突变株PKU#PM003可作为性状优良的工业化发酵生产菌种,并在DHA产量提升上仍具有巨大的空间。

[Objective] Mutants of Aurantiochytrium sp. PKU#SW7 were screened for high docosahexanoic acid（DHA） yield. [Methods] UV mutagenesis and chemical stress screening were used to mutate Aurantiochytrium sp. PKU#SW7, with biomass production, lipid content and DHA yield as screening criteria to obtain mutant strains. [Results] Mutant PKU#PM003 presented stable high DHA yield in 4 generations. In lab fermentation the biomass of this strain reached 6.62 g/L, improved by 11.26% compared to that of the original wild strain; the lipid content of the mutant reached 4.01 g/L, improved by 26.1% compared to the original. The DHA content in total fatty acids also increased from 29.97% to 33.43% and the DHA yield of PKU#PM003 increased by 41.1%. [Conclusion] The mutant strain PKU# PM003 could be used as a potential strain for industrial fermentation.