Strobel H J
Department of Animal Sciences, University of Kentucky, Lexington 40546-0215.
Appl Environ Microbiol. 1992 Jul;58(7):2331-3. doi: 10.1128/aem.58.7.2331-2333.1992.
When Prevotella ruminicola 23 was grown in a defined medium containing a vitamin mixture, significant amounts of propionate were formed. Succinate and acetate were the major fermentation acids produced when vitamins were omitted, and further experiments demonstrated that propionate formation was dependent on vitamin B12. When the organism was grown in continuous culture at dilution rates of less than 0.20 h-1, propionate and acetate were the predominant fermentation products and little succinate was formed when vitamin B12 was present. However, at higher dilution rates, propionate formation declined and succinate accumulated. Since cell protein yields were reduced 15 to 25% in the absence of vitamin B12, the pathway for propionate formation may contain an energy-conserving step.
当瘤胃普雷沃氏菌23在含有维生素混合物的限定培养基中生长时，会形成大量丙酸。当省略维生素时，琥珀酸和乙酸是产生的主要发酵酸，进一步的实验表明丙酸的形成依赖于维生素B12。当该生物体在稀释率低于0.20 h-1的连续培养中生长时，当存在维生素B12时，丙酸和乙酸是主要的发酵产物，几乎不形成琥珀酸。然而，在较高的稀释率下，丙酸的形成减少，琥珀酸积累。由于在没有维生素B12的情况下细胞蛋白质产量降低了15%至25%，丙酸形成途径可能包含一个能量保存步骤。
