Exploration of the metabolic flexibility of glycogen accumulating organisms through metatranscriptome analysis and metabolic characterization  

作　　者：Bin Zhao Yanping Yang Chen Zhao Chunchun Zhang Zhaohui Zhang Liang Wang Shang Wang Jingfeng Wang 

机构地区：[1]School of Environmental Science Engineering,Tiangong University,Tianjin 300387,China [2]Department of Hygienic Toxicology and Environmental Hygiene,Tianjin Institute of Environmental and Operational Medicine,Tianjin 300201,China

出　　处：《Journal of Environmental Sciences》2023年第4期234-248,共15页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.51678565);the Special Fund of China (No.AWS18J004);the Tianjin Natural Science Foundation (Nos.19JCYBJC_(2)3800, 19JCZDJC_(3)9800);the National Key R&D Program of China (No.2018YFD0800104)。

摘　　要：Glycogen accumulating organisms(GAOs) are closely related to the deterioration of enhanced biological phosphorus removal systems. However, the metabolic mechanisms that drive GAOs remain unclear. Here, the two-thirds supernatant of a reactor were decanted following the anaerobic period to enrich GAOs. Long-term monitoring demonstrated that the system was stable and exhibited typical characteristics of GAOs metabolism. Acetate was completely consumed after 60 min of the anaerobic phase. The level of glycogen decreased from 0.20 to 0.14 g/gSS during the anaerobic phase, whereas the level of glycogen significantly increased to 0.21g/gSS at the end of the aerobic period. Moreover, there was almost no phosphate release and absorption in the complete periods, thus confirming the successful construction of a GAOs enrichment system. Microbial community analysis demonstrated that Ca. Contendobacter was among the core functional genera and showed the highest activity among all of the communities. Furthermore, our study is the first to identify the involvement of the ethyl-malonyl-CoA pathway in the synthesis of polyhydroxyvalerate via croR, ccr, ecm, mcd, mch and mcl genes. The Embden-Meyerhof-Parnas(EMP) pathway was preferentially used via glgP. Furthermore, the glyoxylate cycle was the main source of ATP under anaerobic conditions, whereas the tricarboxylic acid cycle provided ATP under aerobic conditions. aceA and mdh appeared to be major modulators of the glyoxylate pathway for controlling energy flow. Collectively, our findings not only revealed the crucial metabolic mechanisms in a GAOs enrichment system but also provided insights into the potential application of Ca. Contendobacter for wastewater treatment.

关 键 词：Glycogen accumulating organisms Intracellular storage Metatranscriptome Bacterial community Glyoxylate pathway 

分 类 号：X172[环境科学与工程—环境科学] X703