ACETIC-ACID FORMATION IN ESCHERICHIA-COLI FERMENTATION
ACETIC-ACID FORMATION IN ESCHERICHIA-COLI FERMENTATION
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DOI：
10.1002/bit.260390611
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发表时间：
1992-03-15
影响因子：
3.8
通讯作者：
HONG, J
中科院分区：
文献类型：
--
作者：
HAN, K;LIM, HC;HONG, J
在连续培养中研究了大肠杆菌发酵中乙酸的形成。实验结果表明，有限的氧化代谢能力（可能是有限的TCA循环能力）可能是负责乙酸的形成。在低生长速率下，氧化代谢可以满足合成代谢和分解代谢的需要。然而，在高生长速率下，这两种需求可能超过单独的氧化代谢的能力。建议在这种情况下，E.大肠杆菌重组氧化代谢，首先满足合成代谢的要求，然后利用氧化代谢和乙酸形成代谢的剩余能力提供必要量的能量。大肠杆菌选择乙酸合成作为有氧能源，因为它产生第二大量的ATP和NADH 2。根据我们的建议，乙酸的形成可以通过减少合成代谢的需求来减少，即，减少葡萄糖摄取，或通过增加氧化代谢的能力。这两种方法通过观察减少乙酸的形成，通过减少葡萄糖的摄取与酵母提取物添加和增强氧化代谢的能力与甲硫氨酸添加证实。
Acetic acid formation in Escherichia coli fermentation has been studied in continuous cultures. Experimental results suggest that the limited capacity of the oxidative metabolism (perhaps the limited capacity of TCA cycle) may be responsible for acetic acid formation. At low growth rates, both anabolic and catabolic requirements may be satisfied by the oxidative metabolism. However, at high growth rates these two demands may exceed the capacity of the oxidative metabolism alone. It is proposed that under these circumstances, E. coli reorganizes the oxidative metabolism to first meet the anabolic requisition and then supply the necessary amount of energy using both the remaining capacity of the oxidative metabolism and acetic acid formation metabolism. Escherichia coli selects acetic acid synthesis as the aerobic energy source because it generates the second largest amount of ATP and NADH2. According to our proposition, acetic acid formation could be reduced by decreasing the anabolic requirement, i.e., reducing glucose uptake, or by increasing the capacity of the oxidative metabolism. These two approaches were experimentally confirmed by observing reduced acetic acid formation by reducing the glucose uptake with a yeast extract addition and enhancing the capacity of oxidative metabolism with a methionine addition.