TY - JOUR
T1 - Anaerobic digestion of sludge by different pretreatments
T2 - Changes of amino acids and microbial community
AU - Xiao, Keke
AU - Yu, Zecong
AU - Pei, Kangyue
AU - Sun, Mei
AU - Zhu, Yuwei
AU - Liang, Sha
AU - Hou, Huijie
AU - Liu, Bingchuan
AU - Hu, Jingping
AU - Yang, Jiakuan
N1 - Publisher Copyright:
© 2021, Higher Education Press.
PY - 2022/2
Y1 - 2022/2
N2 - 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. [Figure not available: see fulltext.]
AB - 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. [Figure not available: see fulltext.]
KW - Amino acids
KW - Dissolved organic nitrogen
KW - Metagenomic sequencing analysis
KW - Proteins
KW - Sludge pretreatments
KW - Structural equation model
UR - http://www.scopus.com/inward/record.url?scp=85109168499&partnerID=8YFLogxK
U2 - 10.1007/s11783-021-1458-7
DO - 10.1007/s11783-021-1458-7
M3 - 文章
AN - SCOPUS:85109168499
SN - 2095-2201
VL - 16
JO - Frontiers of Environmental Science and Engineering
JF - Frontiers of Environmental Science and Engineering
IS - 2
M1 - 23
ER -