School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255000, China.
School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255000, China.
J Environ Manage. 2024 Apr;356:120632. doi: 10.1016/j.jenvman.2024.120632. Epub 2024 Mar 26.
To provide a sufficient supply of electron donors for the synthesis of caproic acid, yeast fermentation was employed to increase ethanol production in the anaerobic fermentation of Chinese cabbage waste (CCW). The results showed that the caproic acid yield of CCW with ethanol pre-fermentation was 7750.3 mg COD/L, accounting for 50.2% of the total volatile fatty acids (TVFAs), which was 32.5% higher than that of the CCW without yeast inoculation. The synchronous fermentation of yeast and seed sludge significantly promoted the growth of butyric acid consuming bacterium Bacteroides, resulting in low yields of butyric acid and caproic acid. With yeast inoculation, substrate competition for the efficient ethanol conversion in the early stage of acidogenic fermentation inhibited the hydrolysis and acidfication. Without yeast inoculation, the rapid accumulation of TVFAs severely inhibited the growth of Bacteroidetes. In the reactor with ethanol pre-fermentation, the key microorganism for caproic acid production, Clostridium_sensu_stricto_12, was selectively enriched.
为了提供足够的电子供体用于己酸的合成，采用酵母发酵来提高厌氧发酵白菜废物（CCW）中的乙醇产量。结果表明，经乙醇预发酵的 CCW 的己酸产率为 7750.3mg COD/L，占总挥发性脂肪酸（TVFAs）的 50.2%，比未接种酵母的 CCW 高 32.5%。酵母和种泥的同步发酵显著促进了丁酸消耗菌丁酸梭菌的生长，导致丁酸和己酸的产量较低。接种酵母后，产酸发酵早期对高效乙醇转化的基质竞争抑制了水解和酸化。不接种酵母时，TVFAs 的快速积累严重抑制了拟杆菌门的生长。在进行乙醇预发酵的反应器中，己酸产生的关键微生物梭菌属 12 型被选择性富集。
