Iannotti E L, Kafkewitz D, Wolin M J, Bryant M P
J Bacteriol. 1973 Jun;114(3):1231-40. doi: 10.1128/jb.114.3.1231-1240.1973.
The influence of a H(2)-utilizing organism, Vibrio succinogenes, on the fermentation of limiting amounts of glucose by a carbohydrate-fermenting, H(2)-producing organism, Ruminococcus albus, was studied in continuous cultures. Growth of V. succinogenes depended on the production of H(2) from glucose by R. albus. V. succinogenes used the H(2) produced by R. albus to obtain energy for growth by reducing fumarate in the medium. Fumarate was not metabolized by R. albus alone. The only products detected in continuous cultures of R. albus alone were acetate, ethanol, and H(2). CO(2) was not measured. The only products detected in the mixed cultures were acetate and succinate. No free H(2) was produced. No formate or any other volatile fatty acid, no succinate or other dicarboxylic acids, lactate, alcohols other than ethanol, pyruvate, or other keto-acids, acetoin, or diacetyl were detected in cultures of R. albus alone or in mixed cultures. The moles of product per 100 mol of glucose fermented were approximately 69 for ethanol, 74 for acetate, 237 for H(2) for R. albus alone and 147 for acetate and 384 for succinate for the mixed culture. Each mole of succinate is equivalent to the production of 1 mol of H(2) by R. albus. Thus, in the mixed cultures, ethanol production by R. albus is eliminated with a corresponding increase in acetate and H(2) formation. The mixed-culture pattern is consistent with the hypothesis that nicotinamide adenine dinucleotide (reduced form), formed during glycolysis by R. albus, is reoxidized during ethanol formation when R. albus is grown alone and is reoxidized by conversion to nicotinamide adenine dinucleotide and H(2) when R. albus is grown with V. succinogenes. The ecological significance of this interspecies transfer of H(2) gas and the theoretical basis for its causing changes in fermentation patterns of R. albus are discussed.
在连续培养中,研究了利用氢气的产琥珀酸弧菌对碳水化合物发酵产氢的白瘤胃球菌发酵限量葡萄糖的影响。产琥珀酸弧菌的生长依赖于白瘤胃球菌从葡萄糖产生氢气。产琥珀酸弧菌利用白瘤胃球菌产生的氢气,通过还原培养基中的富马酸来获取生长所需的能量。富马酸不能被白瘤胃球菌单独代谢。在单独培养白瘤胃球菌的连续培养物中检测到的唯一产物是乙酸盐、乙醇和氢气。未测量二氧化碳。在混合培养物中检测到的唯一产物是乙酸盐和琥珀酸盐。未产生游离氢气。在单独培养白瘤胃球菌或混合培养的培养物中,均未检测到甲酸盐或任何其他挥发性脂肪酸、琥珀酸盐或其他二羧酸、乳酸、除乙醇外的醇类、丙酮酸或其他酮酸、乙偶姻或双乙酰。单独培养白瘤胃球菌时,每发酵100摩尔葡萄糖产生的产物摩尔数约为乙醇69、乙酸盐74、氢气237;混合培养时,乙酸盐为147,琥珀酸盐为384。每摩尔琥珀酸盐相当于白瘤胃球菌产生1摩尔氢气。因此,在混合培养中,白瘤胃球菌的乙醇产生被消除,同时乙酸盐和氢气的形成相应增加。混合培养模式与以下假设一致:白瘤胃球菌在糖酵解过程中形成的烟酰胺腺嘌呤二核苷酸(还原型),在白瘤胃球菌单独生长时乙醇形成过程中被重新氧化,而在白瘤胃球菌与产琥珀酸弧菌共同生长时通过转化为烟酰胺腺嘌呤二核苷酸和氢气被重新氧化。讨论了这种种间氢气转移的生态意义及其导致白瘤胃球菌发酵模式变化的理论基础。