Enrichment of caproate bacteria and its application in caproic acid production from food waste
ZHANG Yan-yan1, BAI Jia-zhe2, ZUO Jian-e1,2
1. State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; 2. Tsinghua Shenzhen International Graduate School, Shenzhen 518055, China
Abstract:This study investigated three different electron donor combinations to attain maximum enrichment of caproic acid bacteria and the ability of these enriched bacteria to further digest food waste without the addition of external electron donors. Three batch experiments were performed using ethanol, lactate, and ethanol plus lactate as electron donors. The results showed that the highest concentration of caproic acid ((2303.06±499.56) mg COD/L) was reached when ethanol and lactate were both used as electron donors which was justified by the significant increase in the microbial population of caproate bacterial genera such as Clostridium_sensu_stricto_12 (16.04%±0.16%), Caproiciproducens (28.78%±0.15%) and Oscillibacter (2.32%±0.03%). When this enriched culture was inoculated to food waste, the maximum concentration of caproate reached (8657.36±996.21) mg COD/L, and the caproic acid yield and specificity were (230.05±26.47) mg COD/g VS and 27.74%±3.19% respectively. This study proved that caproic acid bacteria are significantly enriched in the presence of the electron donor combination of ethanol and lactate, and that the enriched inoculum can promote caproic acid production from food waste. These results provide theoretical support for the recovery of resources from food waste.
张艳艳, 白佳喆, 左剑恶. 己酸菌富集及其利用餐厨垃圾产己酸的研究[J]. 中国环境科学, 2022, 42(6): 2724-2733.
ZHANG Yan-yan, BAI Jia-zhe, ZUO Jian-e. Enrichment of caproate bacteria and its application in caproic acid production from food waste. CHINA ENVIRONMENTAL SCIENCECE, 2022, 42(6): 2724-2733.
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