Dombek K M, Ingram L O
Appl Environ Microbiol. 1987 Jun;53(6):1286-91. doi: 10.1128/aem.53.6.1286-1291.1987.
During batch fermentation, the rate of ethanol production per milligram of cell protein is maximal for a brief period early in this process and declines progressively as ethanol accumulates in the surrounding broth. Our studies demonstrate that the removal of this accumulated ethanol does not immediately restore fermentative activity, and they provide evidence that the decline in metabolic rate is due to physiological changes (including possible ethanol damage) rather than to the presence of ethanol. Several potential causes for the decline in fermentative activity have been investigated. Viability remained at or above 90%, internal pH remained near neutrality, and the specific activities of the glycolytic and alcohologenic enzymes (measured in vitro) remained high throughout batch fermentation. None of these factors appears to be causally related to the fall in fermentative activity during batch fermentation.
在分批发酵过程中,每毫克细胞蛋白的乙醇产生速率在该过程早期的短时间内达到最大值,并随着乙醇在周围发酵液中的积累而逐渐下降。我们的研究表明,去除这种积累的乙醇并不能立即恢复发酵活性,并且研究提供了证据表明代谢速率的下降是由于生理变化(包括可能的乙醇损伤)而非乙醇的存在。已经研究了发酵活性下降的几个潜在原因。在整个分批发酵过程中,细胞活力保持在90%或以上,内部pH值保持接近中性,糖酵解酶和产醇酶的比活性(体外测量)保持较高。这些因素似乎都与分批发酵过程中发酵活性的下降没有因果关系。