本试验旨在研究添加外源信号分子N-己酰基-高丝氨酸内酯(C6-HSL)对食品废水低温(15℃)厌氧消化的影响。每天添加0.4μmolC6-HSL可使平均化学需氧量去除率从45.98%提高到94.92%,间歇添加(每五天添加2μmolC6-HSL)使其从45.98%增加到72.44%。这两种模式的C6-HSL添加使蛋白酶和乙酸激酶活性分别提高了47.99%/8.04%和123.26%/127.91%,辅酶F420浓度分别增加15.79%和63.16%,分别。C6-HSL影响了松散结合的细胞外聚合物合成的调节,增加了污泥中蛋白质和多糖的含量。添加C6-HSL后,厚壁菌和拟杆菌的相对丰度增加。连续加入C6-HSL后,相关功能基因的相对丰度,如amy,apgM,aceE,和accC增加,表明产甲烷菌获得了足够的底物。糖酵解相关功能基因的丰度,如glk,pfk,PGI,tpia,间隙,pgk,gpmA,eno,加入C6-HSL后pyk增加,保证厌氧污泥在低温下对有机物的高效转化和吸收。本研究为C6-HSL低温强化食品废水厌氧消化的机理提供了新的综合见解。
This experiment aimed to study the effects of adding the exogenous signaling molecule N-hexanoyl-homoserine lactone (C6-HSL) on the anaerobic digestion of food wastewater at low temperature (15 °C). Daily addition of 0.4 μmol C6-HSL increased the average chemical oxygen demand removal from 45.98% to 94.92%, while intermittent addition (adding 2 μmol C6-HSL every five days) increased it from 45.98% to 72.44%. These two modes of C6-HSL addition increased protease and acetate kinase activity by 47.99%/8.04% and 123.26%/127.91% respectively, and increased coenzyme F420 concentrations by 15.79% and 63.16%, respectively. The regulation of loosely bound extracellular polymeric substances synthesis was influenced by C6-HSL, which increased protein and polysaccharide content in sludge. The relative abundance of Firmicutes and Bacteroidetes increased following addition of C6-HSL. After continuous addition of C6-HSL, the relative abundance of related functional genes such as amy, apgM, aceE, and accC increased, indicating that methanogens obtained sufficient substrate. The abundance of glycolysis-related functional genes such as glk, pfk, pgi, tpiA, gap, pgk, gpmA, eno, and pyk increased after the addition of C6-HSL, ensuring the efficient transformation and absorption of organic matter by anaerobic sludge at low temperatures. This study provides new comprehensive insights into the mechanism behind the enhancement of food wastewater anaerobic digestion by C6-HSL at low temperature.