Anaerobic digestion of sludge by different pretreatments:Changes of amino acids and microbial community  

作　　者：Keke Xiao Zecong Yu Kangyue Pei Mei Sun Yuwei Zhu Sha Liang Huijie Hou Bingchuan Liu Jingping Hu Jiakuan Yang 

机构地区：[1]School of Environmental Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China [2]Hubei Provincial Engineering Laboratory of Solid Waste Treatment,Disposal and Recycle Technology,Wuhan 430074,China [3]State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan 430074,China

出　　处：《Frontiers of Environmental Science & Engineering》2022年第2期109-123,共15页环境科学与工程前沿（英文）

基　　金：The research was supported by the National Natural Science Foundation of China(Grant Nos.51708239 and U1901216);Natural Science Foundation of Hubei Province(No.2020CFA042);Applied Basic Research Program of Wuhan(No.2020020601012277);Additionally,we would also like to thank the Analytical and Testing Center of Huazhong University of Science and Technology for providing experimental measurements.

摘　　要：Many studies have investigated the effects of different pretreatments on the performance of anaerobic digestion of sludge.However,the detailed changes of dissolved organic nitrogen,particularly the release behavior of proteins and the byproducts of protein hydrolysis-amino acids,are rarely known during anaerobic digestion of sludge by different pretreatments.Here we quantified the changes of three types of proteins and 17 types of amino acids in sludge samples solubilized by ultrasonic,thermal,and acid/alkaline pretreatments and their transformation during anaerobic digestion of sludge.Tryptophan protein,aromatic protein I,aromatic protein II,and cysteine were identified as the key dissolved organic nitrogen responsible for methane production during anaerobic digestion of sludge,regardless of the different pretreatment methods.Different from the depletion of other amino acids,cysteine was resistant to degradation after an incubation period of 30 days in all sludge samples.Meanwhile,the“cysteine and methionine metabolism(K00270)”was absent in all sludge samples by identifying 6755 Kyoto Encyclopedia of Genes and Genomes assignments of genes hits.Cysteine contributed to the generation of methane and the degradation of acetic,propionic,and n-butyric acids through decreasing oxidation-reduction potential and enhancing biomass activity.This study provided an alternative strategy to enhance anaerobic digestion of sludge through in situ production of cysteine.

关 键 词：Sludge pretreatments Dissolved organic nitrogen Proteins Amino acids Structural equation model Metagenomic sequencing analysis 

分 类 号：X70[环境科学与工程—环境工程]