Isaacson H R, Hinds F C, Bryant M P, Owens F N
J Dairy Sci. 1975 Nov;58(11):1645-59. doi: 10.3168/jds.S0022-0302(75)84763-1.
Mixed bacterial cultures derived from the rumen were grown in a remen fluid medium in a chemostat at three dilution rates (.02, .06, and .12 per h), each at four growth-limiting glucose concentrations (5.8, 9.9, 12.7, and 25.0 mM). Microscopic observations indicated that a relatively complex mixture of bacterial species was maintained and proportions of fermentations products were similar to those of the rumen except for elevated proportions of methane and acetate. Cell concentration increased linearly with increases in glucose concentration. The range of glucose concentrations had little effect on yields of cells or products produced per mole of glucose fermented. With increases in dilution rates, the amount of butyrate and methane produced per mole of glucose fermented decreased and the amount of propionate increased. Yield glucose (grams cells produced per mole of glucose fermented) increased from 42 at a dilution rate of .02 to 84 at a dilution rate of .12. These large increases are discussed in relationship to the energy requirements for maintenance of bacteria. A theoretical maximum yield glucose of 89.3 and a maintenance requirement of .26 mmol glucose per g cells per h were calculated. Moles of adenosine triphosphate produced per mole of glucose fermented and yield of cells produced per mole of adenosine triphosphate are discussed.
从瘤胃中获取的混合细菌培养物，在恒化器中的瘤胃液培养基里，以三种稀释率（每小时0.02、0.06和0.12）进行培养，每种稀释率下设置四种生长限制葡萄糖浓度（5.8、9.9、12.7和25.0 mM）。显微镜观察表明，维持了相对复杂的细菌种类混合物，发酵产物的比例与瘤胃中的相似，但甲烷和乙酸盐的比例有所升高。细胞浓度随葡萄糖浓度的增加呈线性增加。葡萄糖浓度范围对每摩尔发酵葡萄糖产生的细胞或产物产量影响不大。随着稀释率的增加，每摩尔发酵葡萄糖产生的丁酸盐和甲烷量减少，丙酸盐量增加。产率葡萄糖（每摩尔发酵葡萄糖产生的细胞克数）从稀释率为0.02时的42增加到稀释率为0.12时的84。结合细菌维持所需的能量需求对这些大幅增加进行了讨论。计算得出理论最大产率葡萄糖为89.3，维持需求为每克细胞每小时0.26 mmol葡萄糖。讨论了每摩尔发酵葡萄糖产生的三磷酸腺苷摩尔数以及每摩尔三磷酸腺苷产生的细胞产量。
