使用稀禾定驯化提高裂殖壶菌的生长和DHA积累  

Improving growth and DHA production of Schizochytrium sp. by sethoxydim-based adaptive evolution

作　　者：王康[1] 刘良森[1] 陈磊[1] 张卫文[1] 

机构地区：[1]天津大学化工学院,天津300350

出　　处：《食品与发酵工业》2017年第7期42-48,共7页Food and Fermentation Industries

基　　金：国家自然科学基金(21621004);国家"973"计划(2014CB745101);高等学校博士学科点专项科研基金(20120032110020;20130032120022);天津市应用基础与前沿技术研究计划(15JCZDJC32500)

摘　　要：采用基于实验室的微生物适应性驯化方法,对Schizochytrium sp.S31进行脂肪酸合成途径抑制剂稀禾定连续传代驯化,逐步提高稀禾定的驯化浓度。经过近200天连续驯化65代,Schizochytrium sp.S31对稀禾定的耐受浓度从200μmol/L提高到了500μmol/L。通过250 m L摇瓶发酵96 h后发现,驯化株的生物量明显高于野生株的生物量,其中驯化株ALE500的生物量最高,比相同时间点野生株的生物量高20.2%,二十二碳六烯酸(Docosahexaenoic acid,DHA)产量也提高了30.4%。此外,驯化株的脂肪酸不饱和度也有所提高,其中驯化株ALE500的不饱和度达到了1.11。采用5 L发酵罐验证驯化效果,结果显示驯化株ALE500的生物量和DHA产量分别提高了19.74%和29.38%。综上所述,使用脂肪酸合成途径抑制剂稀禾定对裂殖壶菌进行定向驯化的方法可以提高裂殖壶菌的发酵生物量和DHA产量。Laboratory-based adaptive evolution was applied to increase the tolerance to ACCase inhibitor se- thoxydimin Schizochytrium sp. $31. Through an experimental evolution process of continuous 65 passages for 200 days, the sethoxydim tolerance concentration in Schizochytrium sp. was increased from 200 μmol/L to 500 μmol/L. After 96 h fermentation in shake flasks, a comparative analysis of wild type and evolved strains showed that the bio- mass of the final evolved strain ALE500 reached 14.7 g/L at 72 h, which was 20.2% higher than that of wild type. In addition, docosahexaenoic acid （DHA） yield was increased by 30.4% in the evolved strain compared with the wild type. Moreover, the unsaturation degree of total fatty acids was also significantly increased in the evolved strain ALE500 and reached 1.11. To further verify the domestication effect of evolved strain, fed-batch strategy was applied and 19.74% increase of biomass and 29.38% increase of DHA yield were observed. This study demonstrated that the application of the sethoxydim-tolerance increased the biomass accumulation and DHA production in Schizochytrium sp. S31.

关 键 词：裂殖壶菌 稀禾定 驯化 生物量 DHA 

分 类 号：TQ645.6[化学工程—精细化工] TQ929[轻工技术与工程—发酵工程]