Liu Fengqin, Zhang Yu, Shen Wenyan, Wu Zhenguo, Yang Jiale, Zhang Yifan, Li Jiuling, Chen Yun, Zhang Yupeng, Yuan Zhiliang
College of Life Sciences, Henan Agricultural University, No.63 Agricultural Road, Zhengzhou, 450002, China.
College of Resources and Environmental Sciences, Henan Agricultural University, No.63 Agricultural Road, Zhengzhou, 450002, China.
Chemosphere. 2024 Aug;362:142640. doi: 10.1016/j.chemosphere.2024.142640. Epub 2024 Jun 18.
Exogenous quorum sensing (QS) molecular can regulate the activity and granulation process of anaerobic sludge in anaerobic digestion process, but would be impractical as a standalone operation. Here we demonstrated that application of 1 mg L boric acid assisted in an upflow anaerobic sludge blanket (UASB) reactor recovery from volatile fatty acids (VFAs) accumulation. After VFAs accumulation, the chemical oxygen demand (COD) removal suddenly reduced from 78.98% to 55.86%. The relative abundance of acetoclastic methanogens decreased from 55.79% to 68.28%-23.14%∼25.41%, and lead to the acetate accumulate as high as 1317.03 mg L. Granular sludge disintegrated and the average size of sludge decreased to 586.38 ± 42.45 μm. Application of 1 mg L boric acid activated the interspecies QS signal (AI-2) and then induced the secretion of intraspecies QS signal (N-acyl-homoserine lactones, AHLs). AHLs were then stimulated the growth of syntrophic acetate oxidizing bacteria and hydrogenotrophic methanogen. Moreover, the concentration of acetate decreased to 224.50 mg‧L, and the COD removal increased to 75.10% after application of 1 mg L boric acid. The activated AI-2 may induce multiple quorum-sensing circuits enhance the level of AI-2 and AHLs in parallel, and in turn assisted in anaerobic digestion recovery from VFAs accumulation.
外源性群体感应（QS）分子可在厌氧消化过程中调节厌氧污泥的活性和颗粒化过程，但作为一种独立操作并不实用。在此，我们证明了在升流式厌氧污泥床（UASB）反应器中添加1mg/L硼酸有助于从挥发性脂肪酸（VFA）积累中恢复。VFA积累后，化学需氧量（COD）去除率突然从78.98%降至55.86%。乙酸裂解产甲烷菌的相对丰度从55.79%降至68.28%-23.14%∼25.41%，导致乙酸积累高达1317.03mg/L。颗粒污泥解体，污泥平均粒径降至586.38±42.45μm。添加1mg/L硼酸激活了种间QS信号（AI-2），进而诱导了种内QS信号（N-酰基高丝氨酸内酯，AHLs）的分泌。AHLs随后刺激了互营乙酸氧化菌和氢营养型产甲烷菌的生长。此外，添加1mg/L硼酸后，乙酸浓度降至224.50mg‧L，COD去除率提高到75.10%。被激活的AI-2可能诱导多个群体感应回路同时提高AI-2和AHLs的水平，进而有助于从VFA积累中恢复厌氧消化。
