分批补料对木糖发酵生产乙醇的影响

以树干毕赤酵母为发酵菌种,纯木糖为发酵底物,通过分批补料来提高糖利用率以及乙醇得率。结果表明,在24h内,最佳初始木糖浓度为80g/L,在28h的发酵周期中,可以将木糖浓度提高至90g/L,在32h发酵周期内可以将木糖浓度提高至100g/L。通过分批补料,乙醇浓度得到明显提高。当总糖浓度分别为80g/L、90g/L时,24h发酵周期内,分批补料次数以1次为宜,乙醇浓度分别达30.95g/L、32.60g/L,相比于不补料即一次性投料,乙醇浓度分别提高了9.36%、9.18%。总糖浓度100g/L,28h发酵周期内,补料2次效果最佳,乙醇浓度达37.49g/L,比一次性投料下提高了10.36%,较一次性投料达到相同发酵效果缩短了4h。

Influence of fed-batch for fermentation of xylose to ethanol

Fermentation of xylose to ethanol was investigated with Pichia stipitis. The fed-batch was used to increase the useful yield of sugar and rate of ethanol. The results showed that the best initial xylose concentration was 80g/L in 24h. In 28h of fermentation cycle, the concentration of xylose could be increased to 90g/L. In 32h of fermentation cycle, the concentration of xylose could be increased to lOOg / L. By fed-batch, concentration of ethanol increased obviously. It was better for only once by fed-batch when total concentrations of xylose were 80g/L and 90g/L, respectively in fermentation of 24h. And concentrations of ethanol were 30. 95g/L and 32. 60g/L, respectively. The concentrations of ethanol increased 9. 36% and 9. 18%, respectively comparing with no fed-batch. It was better for twice by fed-batch when total concentration of xylose was 100g/L in fermentation of 28h. The concentration of ethanol was 37.49g/L. The concentration of ethanol increased 10. 36% comparing with no fed-batch. The fermentatron cycle was less than 4h comparing with no fed-batch for fermentation.