利用木糖发酵生产乙醇的好食脉孢菌选育及其发酵条件优化

Breeding of Neurospora sitophila to produce ethanol from xylose and optimization of fermentation conditions

通过高压富集法,从土壤中分离筛选得到一株纤维素降解菌株,并对其木糖发酵特性进行初步研究。根据菌株的形态特性和生理生化特征,初步鉴定为好食脉孢菌(Neurospora sitophila)。结果表明,该菌株CMC酶活力为3 554.88 U·g-1、FPA酶活力为506.76 U·g-1,当紫外线照射剂量30 W,照射距离20 cm,照射时间为8min时,致死率为77.28%。在木糖浓度20 g·L-1、发酵温度25℃、发酵时间96 h、转速140 r·min-1的条件下乙醇产量可达5.5 g·L-1,乙醇得率为理论值的59.8%。

Using the high pressure enrichment method, one bacteria strian were separated from soil,which can identified as cellulose degradation strains, and the xylose fermentation characteristics were studied. According to the morphological characteristics and physiological and biochemical characteristics of strains this strian was initially identified as Neurospora sitophila. The strain of CMC enzyme activity of 3 554.88 U · g-1, FPA enzyme activity of 506.76 U· g-1, when ultraviolet irradiation dose 30 W, 20 cm distance, the irradiation time of 8 min, the fatality rate was 77.28%. The xylose concentration 20 g· L-1, 25℃ fermentation temperature, fermentation time 96 h, under speed 140 rmp of ethanol production could reach 5.5 g· L-1, the ethanol yield for 59.8% of the theoretical value.