Appl Environ Microbiol. 1997 Mar;63(3):827-33. doi: 10.1128/aem.63.3.827-833.1997.
The bacterial copolyester poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) was produced with Alcaligenes eutrophus DSM 545 from glucose and sodium propionate in a fed-batch fermentation with both nitrogen limitation and low dissolved-oxygen concentrations. When the dissolved-oxygen content was kept between 1 and 4% of air saturation during the polymer accumulation phase, the yield of 3-hydroxybutyrate (3HB) monomer from glucose was not affected, but the propionate-to-3-hydroxyvalerate (3HV) monomer yield was two to three times (0.48 to 0.73 mol of 3HV mol of propionate consumed(sup-1)) that observed in a control experiment (0.25 mol mol(sup-1)), where the accumulation-phase dissolved-oxygen concentration was 50 to 70% of air saturation. The overall polymer productivity of the fermentation was somewhat decreased by low dissolved-oxygen contents, owing to a slower 3HB production rate. The effect of a low dissolved-oxygen concentration is probably attributable to a reduction of the oxygen-requiring decarbonylation of propionyl-coenzyme A (CoA) to acetyl-CoA.
细菌共聚酯聚(3-羟基丁酸酯-co-3-羟基戊酸酯)是由葡萄糖和丙酸钠在补料分批发酵中,利用氮限制和低溶解氧浓度,由 Alcaligenes eutrophus DSM 545 生产的。当聚合物积累阶段的溶解氧含量保持在空气饱和度的 1%至 4%之间时,葡萄糖中 3-羟基丁酸(3HB)单体的产率不受影响,但丙酸与 3-羟基戊酸(3HV)单体的产率是对照实验(0.25 mol mol(sup-1))中观察到的两倍到三倍(0.48 至 0.73 mol 3HV mol 消耗的丙酸(sup-1)),其中积累阶段的溶解氧浓度为空气饱和度的 50%至 70%。由于 3HB 生产速率较慢,低溶解氧含量会使发酵的整体聚合物生产力略有下降。低溶解氧浓度的影响可能归因于减少了需要氧气的丙酰辅酶 A(CoA)脱羧化为乙酰辅酶 A。