添加氮源和金属离子提高深黄伞形霉利用麸皮水解液积累油脂的研究

Enhancing of lipid accumulation of Umbelopsis isabellina by addition of ammonium and metal ion in the wheat bran hydrolysate

深黄伞形霉是积累油脂的重要微生物,以深黄伞形霉利用麸皮水解液生成油脂有利于麸皮的综合利用。基于前期研究,在麸皮水解液中添加氮源、金属离子提高了油脂产量和麸皮水解液中糖分的利用。当乙酸铵添加至氮元素为1.5 g/L时,深黄伞形霉的生物量达到最大值25.8 g/L。乙酸铵添加至氮元素为1.0 g/L时,油脂产量提高11%。麸皮水解液中添加Mg^(2+)、Ca^(2+)和Mn^(2+)促进深黄伞形霉的代谢和脂肪合成。当添加0.5 g/L CaCl_(2)、1.0 g/L MgSO_(4)、8μg/L MnSO_(4)时油脂产量分别提高脂肪酸分别达到13.8、10.26、12.91 g/L,分别提高了39.8%、65.8%、30.8%。研究结果为麸皮的综合利用提供了参考。

Umbelopsis(Mortierella)isabellina is an important oleaginous microbial species.Lipid production by U.isabellina using wheat bran hydrolysate benefits the utilization of wheat bran.Based on our previous study,this study investigated the influences of nitrogen sources and metal ions on cell growth and lipid production of U.isabellina,and carbon source utilization.The results showed that the maximum of biomass was obtained at 1.5 g/L nitrogen using ammonium acetate,and 11%increment of oil production at 1.0 g/L nitrogen using ammonium acetate.The addition of Mg^(2+),Ca^(2+)and Mn^(2+)in wheat bran hydrolysate promoted carbon metabolism and lipid synthesis of U.isabellina.The lipid yield reached 13.8,10.26,12.91 g/L with 39.8%,65.80%,30.8%increment respectively at 0.5 g/L CaCl_(2),1.0 g/L MgSO_(4),8μg/L MnSO_(4)addition.These results provided a base for application of wheat bran in food industry.