Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Department of Water Engineering and Science, College of Civil Engineering, Hunan University, Changsha, Hunan 410082, PR China.
Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Department of Water Engineering and Science, College of Civil Engineering, Hunan University, Changsha, Hunan 410082, PR China.
Bioresour Technol. 2021 Jun;329:124893. doi: 10.1016/j.biortech.2021.124893. Epub 2021 Feb 26.
The objective of this study was to understand how lactate-to-butyrate ratio and substrates concentrations affect the caproate production and product structure. The results showed that a higher butyrate-to-lactate ratio is beneficial to caproate production at low initial lactate concentration. Low pH (5.0) and low substrate concentration (20 mM and 40 mM) effectively decreased propionate production via restrained acrylate pathway, resulting in higher electron efficiency of caproate. With the optimum mole ratio of lactate to butyrate (1:4) and 80 mM initial butyrate concentration, the electron efficiency of caproate reached the maximum (43.10%). Moreover, high butyrate concentration suppressed the production of odd-carbon-number carboxylates while promoting the production of caproate. Compared with the batch operation, the caproate production in semi-continuous operation was enhanced by 3.45 times to 30.91 ± 1.07 mM as the acrylate pathway was successfully inhibited in semi-continuous experiments due to low pH and low lactate concentration.
本研究旨在探讨乳酰/丁酰比值和底物浓度如何影响己酸的产生和产物结构。结果表明，在低初始乳酸浓度下，较高的丁酰/乳酰比值有利于己酸的产生。低 pH 值（5.0）和低底物浓度（20mM 和 40mM）通过抑制丙烯酰途径有效降低丙酸产量，从而提高己酸的电子效率。在最佳的乳酸/丁酸盐摩尔比（1:4）和 80mM 初始丁酸盐浓度下，己酸的电子效率达到最大值（43.10%）。此外，高丁酸盐浓度抑制了奇数碳羧酸的产生，同时促进了己酸的产生。与分批操作相比，由于半连续实验中低 pH 值和低乳酸浓度成功抑制了丙烯酰途径，半连续操作中己酸的产量提高了 3.45 倍，达到 30.91±1.07mM。
