外加肌醇对嗜鞣管囊酵母发酵的酒精产量及其耐酒精能力的影响

The Effect of Inositol Addition on Ethanol Production by Fermented and Ethanol Tolerance in Pachysolen tannophilus

嗜鞣管囊酵母(Pachysolen tannophilus)是可以同时发酵葡萄糖和木糖为酒精的菌种,在其生长和发酵培养基中分别添加不同浓度(0～200mg/L)的肌醇以及不同起始浓度的酒精,以考察外加肌醇对嗜鞣管囊酵母生长、产酒精能力和耐酒精能力的影响。结果表明,添加肌醇前后,嗜鞣管囊酵母的生物量及发酵的酒精产量均有所增加。外加肌醇对嗜鞣管囊酵母生长有轻微的刺激作用,酵母生长最适肌醇浓度为150mg/L;而对酵母生长的耐酒精能力却有明显的影响,并且,菌种在YEPD培养基中的耐酒精能力高于在YEPX培养基中的耐酒精能力。经实验测定,肌醇对嗜鞣管囊酵母产酒精能力及发酵的耐酒精能力均有显著的影响。发酵培养基中未添加起始浓度的酒精时,菌种发酵的最适肌醇浓度为100mg/L,此时生成的酒精产量为45.20g/L。当分别添加起始酒精浓度为10%和12%时,随着肌醇浓度的增加,菌种发酵生成的酒精浓度均呈上升趋势;肌醇浓度为200mg/L时,两种起始酒精浓度下,酒精的净生成量均达到最大,分别为17.18g/L和16.68g/L。

Glucose and xylose could be fermented by Pachysolen tannophilus at the same time. In order to investigate the effects of added inositol on cell viability,ethanol production and ethanol tolerance of Pachysolen tarmophilus,different concentrations （0＂~200mg/L）of inositol and different concentrations of initial ethanol were added respectively in the growth media or fermentation media. The result shows that in the presence of inositol there are more yeast biomass and more ethanol production than in the absence of inositol. Addition of inositol has litde effects on growth of Pachysolen tarmophilus,and the most appropriate concentration of inositol for yeast growth was 150mg/L. Furthermore,when the yeast was cultured in YEPD medium,ethanol tolerance was more powerful than in YEPX medium. Additional inositol has remarkable effects on ethanol production and ethanol tolerance. In the absence of initial ethanol,the most appropriate concentration of inositol for yeast fermentation was 100mg/L,while the ethanol production was 45.20g/L. The more added inositol,the more ethanol the yeast produced when the fermentation medium with 10% or 12% initial ethanol. Moreover,the yeast were incubated in the fermentation medium in presence of 10% and 12% initial ethanol,producing the maximum ethanol of 17.18g/L and 16.68g/L using 200mg/L inositol as supplement, respectively. These indicate that the inositol content in these yeast media can play an important role in ethanol production and ethanol tolerance.