【摘要】 以树干毕赤酵母为出发菌株,研究紫外短波照射和60Co-γ辐照2种诱变方法对该菌种利用木糖产乙醇性能的影响,探讨较佳诱变条件。通过绘制菌体生长曲线及发酵曲线,确定了诱变菌最适宜的培养时长为18 h,诱变菌最适宜的发酵时长为48 h。原菌液浓度为107个/ml时,根据诱变后菌液在木糖浓度20 g/L中培养48h的结果可知,紫外处理45~75 s乙醇产率可达0.379 4 g/g,为理论值的74.39%,辐照处理800~1 000 Gy,乙醇产率可达0.316 5 g/g,为理论值的62.06%。因此,紫外及辐照这2种诱变方式在合适的参数条件下均能提高树干毕赤酵母利用木糖产乙醇的转化率。更多还原

【Abstract】 In this study, effects of UV irradiation and60Co-γ irradiation on fermentation of xylose to ethanol by Pichia stipitis were analyzed to investigate the optimal mutagenic conditions. According to the growth curve and fermentation curve of P. stipitis, the optimal incubation duration and fermentation duration of P. stipitis mutant strain were 18 and 48 h, respectively. The cell concentration of original yeast liquid was 107cells/ml. After mutagenesis by UV irradiation and60Co-γ irradiation, yeast liquid was incubated in 20 g/L xylose media for 48 h. According to the results, after UV irradiation for 45-75 s, transformation efficiency reached 0.3794 g/g, which was74.39% of the theoretical value; after irradiation with 800-1 000 Gy60Co-γ, transformation efficiency reached 0.3165 g/g, which was 62.06% of the theoretical value.Therefore, both UV irradiation and60Co-γ irradiation could improve the efficiency of xylose fermentation to ethanol by P. stipitis under appropriate conditions.更多还原