Maiorella B, Blanch H W, Wilke C R
Lawrence Berkeley Laboratory, and Department of Chemical Engineering, University of California, Berkeley, California 94720, USA.
Biotechnol Bioeng. 1983 Jan;25(1):103-21. doi: 10.1002/bit.260250109.
Inhibition by secondary fermentation products may limit the ultimate productivity of new glucose to ethanol fermentation processes. New processes are under development whereby ethanol is selectively removed from the fermenting broth to eliminate ethanol inhibition effects. These processes can concentrate minor secondary products to the point where they become toxic to the yeast. Vacuum fermentation selectively concentrates nonvolatile products in the fermentation broth. Membrane fermentation systems may concentrate large molecules which are sterically blocked from membrane transport. Extractive fermentation systems, employing nonpolar solvents, may concentrate small organic acids. By-product production rates and inhibition levels in continuous fermentation with Saccharomyces cerevisiae have been determined for acetaldehyde, glycerol, formic, lactic, and acetic acids, 1-propanol, 2-methyl-1-butanol, and 2,3-butanediol to assess the potential effects of these by-products on new fermentation processes. Mechanisms are proposed for the various inhibition effects observed.
二次发酵产物的抑制作用可能会限制新型葡萄糖制乙醇发酵工艺的最终生产率。目前正在开发新的工艺，通过该工艺可从发酵液中选择性地去除乙醇，以消除乙醇的抑制作用。这些工艺会将少量的副产物浓缩到对酵母产生毒性的程度。真空发酵可选择性地将非挥发性产物浓缩在发酵液中。膜发酵系统可能会浓缩那些因空间位阻而无法通过膜运输的大分子。采用非极性溶剂的萃取发酵系统可能会浓缩小分子有机酸。已测定了酿酒酵母连续发酵过程中乙醛、甘油、甲酸、乳酸、乙酸、1-丙醇、2-甲基-1-丁醇和2,3-丁二醇的副产物生成速率和抑制水平，以评估这些副产物对新型发酵工艺的潜在影响。针对观察到的各种抑制作用提出了作用机制。
