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›› 2005, Vol. 5 ›› Issue (3): 349-352.

• 生化工程专栏 • 上一篇    下一篇

不同类型载气对乙醇气提发酵的影响

张 君,刘宏娟,刘德华   

  1. 清华大学 化学工程系
  • 出版日期:2005-06-20 发布日期:2005-06-20

Effect of Different Types of Gas in Gas Stripping Ethanol Fermentation (GSEF)

ZHANG Jun,LIU Hong-juan, LIU De-hua   

  1. Department of Chemical Engineering，Tsinghua University
  • Online:2005-06-20 Published:2005-06-20

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摘要： 研究了在乙醇气提发酵过程中，分别使用空气、二氧化碳、氮气和高纯氮作为气提载气对细胞生理及乙醇发酵的影响. 结果表明，空气能维持细胞生长和活力，但发酵效果最差，二氧化碳使细胞发酵能力波动不稳定且抑制副产物甘油合成；而以浓度为99.5%～99.8%的氮气为气提载气取得了较好的效果，乙醇和甘油的生产速率比不气提批式发酵分别提高2倍和1.9倍. 对以高纯氮(99.999%)为气提载气的研究发现，发酵进行到47 h开始出现菌种大量死亡现象，此时适当通氧和补充生长所需营养物质，细胞数量回升，活性恢复，最终乙醇生产速率比不气提时提高1.3倍.

关键词: 气提, 乙醇发酵, 气提因子, 细胞活性, 生产速率

Abstract: The effect of air, CO2, N2 and pure N2 as stripping gas on the cell physiology and ethanol production in GSEF was studied. The experimental results indicate that different stripping gases have different effects on the cell growth as well as ethanol and glycerol production in GSEF. Aeration stimulated cell growth and glycerol production, and maintained cell count and viability, but decreased ethanol productivity. CO2 appeared to be inhibitory to yeast growth and decreased overall glycerol production. 99.5%～99.8% N2 was verified to be the best type of gas in GSEF, for ethanol and glycerol productivity increased respectively by 2 and 1.9 times than that of the control (fed-batch fermentation without gas stripping). Furthermore, study on pure N2 (99.999%) employed in GSEF showed that the rate of cell growth decreased greatly after 47 h of the fermentation. However, the cell count, viability and ethanol productivity could recover original levels when changing the stripping gas from N2 to air, and the data obtained proved that the final ethanol productivity increased by 1.3 times than the control.

Key words: gas stripping, ethanol fermentation, stripping factor, cell viability, productivity