Under anaerobic conditions and in the absence of alternative electron acceptors Escherichia coli converts sugars to a mixture of products by fermentation. The major soluble products are acetate, ethanol, acetate and formate with smaller amounts of succinate. In addition the gaseous products hydrogen and carbon dioxide are produced in substantial amounts. The pathway generating fermentation products is branched and the flow down each branch is varied in response both to the pH of the culture medium and the nature of the fermentation substrate. In particular, the ratio of the various fermentation products is manipulated in order to balance the number of reducing equivalents generated during glycolytic breakdown of the substrate. The enzymes and corresponding genes involved in these fermentation pathways are described. The regulatory responses of these genes and enzymes are known but the details of the underlying regulatory mechanisms are still obscure.

中文翻译：

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大肠杆菌的发酵途径。

在厌氧条件下，在没有其他电子受体的情况下，大肠杆菌通过发酵将糖转化为产物混合物。主要的可溶性产物是乙酸盐，乙醇，乙酸盐和甲酸盐以及少量的琥珀酸盐。另外，大量产生气态产物氢和二氧化碳。产生发酵产物的途径是分支的，并且响应于培养基的pH和发酵底物的性质两者而改变沿每个分支的流动。特别地，各种发酵产物的比例被控制以便平衡在底物​​的糖酵解分解期间产生的还原当量的数量。描述了参与这些发酵途径的酶和相应的基因。