粘性丝孢酵母的诱变及以玉米秸秆水解液为原料产油条件优化

对粘性丝胞酵母进行紫外诱变,获得一株产油率较高的菌株,较原菌株提高了1.53倍。将该菌株接种于用1%硫酸和酶水解处理并浓缩至还原糖浓度为5%的玉米秸秆水解液中培养,生长较好。通过四因素三水平正交实验,确定培养条件为初始pH值7.0、接种量1%、发酵温度30℃、发酵时间5 d时产油率最高。对最佳产油条件进行验证,测得油脂含量为21.3%。从而为利用农业废弃物大规模生产微生物油脂提供了试验数据。气相色谱-质谱联用分析仪显示油脂脂肪酸组成为棕榈酸28.36%,油酸55.86%,10-十八烯酸9.23%,硬脂酸6.70%,可以作为原料生产生物柴油。

Mutagenesis of Trichosporon mucoide and Optimization of Oil Production Conditions Using Straw Hydrolysate as Raw Material

A strain with high oil yield rate was obtained by UV mutagenesis on Trichosporon mucoides, which was 1.53 times higher than that of the original strain. The strain was cultured in the corn straw hydrolysate which was treated with 1% sulfuric acid and enzymatic hydrolysis and condensed to 5% reducing sugar. It was found that the strain grew well. Through the orthogonal experiment of four factors and three levels, the oil yield rate was the highest when the culture conditions including the initial p H of 7.0, the inoculum concentration of 1%, the fermentation temperature of 30℃ and the fermentation time of 5 days. Through verifying the optimal condition of oil yield, the lipid content was measured as 21.3%. Thus, the experiment data might be provided for large-scale production of microbial oil by using agricultural wastes. The analysis of gas-chromatograph and mass spectrometry showed that the oil fatty acid compositions were 28.36% of hexadecanoic acid, 55.86% of oleic acid, 9.23% of10-octadecenoic acid, 6.70% of stearic acid, which could be used as raw material to produce biodiesel.