菌种保藏方法对裂殖壶菌生长及发酵性能的影响

考察保护剂、保藏温度及预冷冻方法对Schizochytrium sp.HX-308菌种存活率及发酵性能保持的影响。结果显示:在-80℃低温保藏6个月后,渗透性保护剂的细胞存活率均比非渗透性保护剂高了5%,其中用60%(质量分数)海藻糖的保护剂最终的株细胞存活率达到80.02%,明显优于其他保护剂。采用液氮-196℃保藏菌种(两步预冷冻法、60%海藻糖保护剂),存储6个月后存活率高达90.70%,生物量、油产量和二十二碳六烯酸(DHA)产量分别达到了61.65、26.41和11.10 g/L,为最优的保藏方法,为裂殖壶菌的实验室研究及工业化生产提供了一种长期安全的保藏法。

Effects of different strain preservation methods on cell growth and fermentation performance of Schizochytrium sp

The effects of cryoprotectants, preservation temperature and different pre-freezing methods on the survival and the fermentation of Schizochytrium sp.HX-308 were investigated.Results of different cryoprotectants showed that cell survival rate when using permeable protective agent was 5% higher than that of unpermeable protective agent after preserved 6 months at -80 ℃. Highest cell survival rate of 80.02% was obtained when using 60% trehalose. In addition,further increase of cell survival rate up to 90.70% was obtained when using a two-step pre-freezing method and 60% trehalose as the cryopretectant after 6 months at -196 ℃.Cell dry weight,lipid yield and docosahexaenoic acid（ DHA） content reached 61.65 g/L,26.41 g/L and 11.10 g/L,respectively-This preservation method was proved to be the best method and could be used as a long period and safe method for the laboratory research and industrial production of Schizochytrium sp.