管囊酵母D-21木糖乙醇发酵条件的优化

对一株能利用木糖产乙醇的管囊酵母D-21进行了发酵条件的优化,研究了接种量、氮源、碳源和维生素对乙醇产量和还原糖利用率的影响。结果表明:接种量过高会影响乙醇产量,以6%(体积分数)为宜;当木糖质量浓度为50 g/L,碳氮质量比为20∶1,使用酵母膏和尿素组成的复合氮源时(质量比为2∶1),发酵72 h后所得乙醇质量浓度为12.5 g/L,达到理论产量的55%;当木糖与葡萄糖的质量比为3∶1时,乙醇质量浓度为15.72 g/L,为理论产量的69%;在发酵培养基中添加质量分数为2×10-5维生素B6可使乙醇产量提高18.3%。

Optimization of the ethanol fermentation of xylose by Pachysolen tannophilus D-21

The effects of varying the inoculum size, nitrogen and carbon sources and added vitamins on the ethanol production and utilization ratio of xylose in the ethanol fermentation of xylose by Pachysolen tannophilus D-21 have been studied. Large inoculum sizes resulted in low yields of ethanol, and the optimum value was found to be 6%. When the xylose concentration was 50g/L, the mass ratio of carbon to nitrogen was 15∶1 and yeast extract and urea (with a mass ratio of 2∶1) was used as the compound nitrogen source, after 72h the mass concentration of ethanol obtained was 12.5g/L, which is 55% of the theoretical yield. When the mass ratio of xylose and glucose was 3∶1, the mass concentration of ethanol obtained was 15.72g/L, which is 69% of the theoretical yield. The ethanol yield is promoted by addition of vitamins and ethanol production was enhanced by 18.3% by adding vitamin B₆. 