Department of Molecular Biology, Autonomous University of Madrid, 28049, Madrid, Spain.
Department of Civil and Environmental Engineering, Laboratory of Environmental Sanitation, Federal University of Pernambuco, Recife, PE, 50740-530, Brazil.
Bioprocess Biosyst Eng. 2024 Jul;47(7):991-1002. doi: 10.1007/s00449-024-03003-6. Epub 2024 Jun 1.
A reactor with silicone tubes as support medium was used for glycerol fermentation. The experimental set-up consisted of three phases. In P1, the applied glycerol loading rate (gly-LR) was in the range of 6-10 g.L.d at an influent pH of 7.9 ± 0.4. In P2, gly-LR was kept constant (18.0 ± 1.8 g.L.d) with different doses of NaHCO. Finally in P3, two different gly-LR (9 and 18 g.L.d) were evaluated, dosing 1 g-NaHCO per g-COD of glycerol. Glycerol consumption was close 90%. The main end-product was 1,3-propanediol (1,3-PDO) (0.40 mol.mol-gly), but ethanol was also generated, particularly at pH above 8 and low gly-LR (0.20 mol.mol-gly). After 1-year operation with glycerol as the only carbon source, a drastic shift in the bacterial community was observed. The 1,3-PDO producers Lacrimispora and Clostridium became dominant, although non-glycerol-degrading fermentative genera, e.g., Actinomyces and Eubacterium, thrived at the expense of cellular breakdown products.
采用硅胶管作为支撑介质的反应堆进行甘油发酵。实验装置分为三个阶段。在 P1 中，采用的甘油进料速率（gly-LR）在 6-10 g.L.d 范围内，入口 pH 值为 7.9 ± 0.4。在 P2 中，gly-LR 保持恒定（18.0 ± 1.8 g.L.d），同时使用不同剂量的 NaHCO3。最后在 P3 中，评估了两种不同的 gly-LR（9 和 18 g.L.d），每克甘油 COD 加 1 克 NaHCO3。甘油消耗接近 90%。主要产物是 1,3-丙二醇（1,3-PDO）（0.40 mol.mol-gly），但也生成了乙醇，特别是在 pH 值高于 8 和 gly-LR 较低（0.20 mol.mol-gly）的情况下。在仅以甘油为碳源运行 1 年后，观察到细菌群落发生了剧烈变化。1,3-PDO 生产者 Lacrimispora 和 Clostridium 占据优势，尽管非甘油降解发酵性属，如 Actinomyces 和 Eubacterium，也以细胞分解产物为代价大量繁殖。
