An RpoN-dependent PEP-CTERM gene is involved in floc formation of an Aquincola tertiaricarbonis strain

BMC Microbiology

Research

Xuezhi Bi¹  Na Gao²  Jingcheng Dai³  Dongru Qiu³  Shuyang Li³  Ming Xia⁴  Dianzhen Yu⁵  Han Chen⁶ 

[1] Bioprocessing Technology Institute, Agency for Science, Technology and Research, 138668, Singapore, Singapore;Fisheries Research Institute, Anhui Academy of Agricultural Sciences, 230031, Hefei, China;Institute of Hydrobiology, Chinese Academy of Sciences, 430072, Wuhan, Hubei Province, China;School of Life Sciences, Hubei Engineering Research Center for Protection and Utilization of Special Biological Resources in the Hanjiang River Basin, Jianghan University, 430056, Wuhan, China;Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Jianghan University, 430056, Wuhan, China;University of Chinese Academy of Sciences, 100049, Beijing, China;Institute for Nutritional Sciences, SIBS, Chinese Academy of Sciences, 200031, Shanghai, China;University of Chinese Academy of Sciences, 100049, Beijing, China;Institute of Hydrobiology, Chinese Academy of Sciences, 430072, Wuhan, Hubei Province, China;

关键词: Bacterial floc formation;    PEP-CTERM proteins;    Flocculation;    RpoN sigma factor;    Aquincola tertiaricarbonis;   

DOI  :  10.1186/s12866-022-02745-1

 received in 2022-01-18, accepted in 2022-12-21,  发布年份 2022

来源: Springer

【 摘 要 】

BackgroundThe floc is a characteristic of microbial aggregate growth, displaying cloudy suspensions in water. Floc formation has been demonstrated in a series of bacteria and the floc-forming bacteria play a crucial role in activated sludge (AS) process widely used for municipal sewage and industrial wastewater treatment over a century. It has been demonstrated that some exopolysaccharide biosynthesis genes and the sigma factor (sigma54 or rpoN) were required for floc forming in some bacteria. However, the mechanism underlying the floc formation stills need to be elucidated.ResultsIn this study, we demonstrate that a TPR (Tetratricopeptide repeats) protein-encoding gene prsT is required for floc formation of Aquincola tertiaricarbonis RN12 and an upstream PEP-CTERM gene (designated pepA), regulated by RpoN1, is involved in its floc formation but not swarming motility and biofilm formation. Overexpression of PepA could rescue the floc-forming phenotype of the rpoN1 mutant by decreasing the released soluble exopolysaccharides and increasing the bound polymers.ConclusionOur results indicate that the wide-spread PEP-CTERM proteins play an important role in the self-flocculation of bacterial cells and may be a component of extracellular polymeric substances required for floc-formation.

【 授权许可】

CC BY   
© The Author(s) 2022

【 图 表 】

Fig. 4

Fig. 2

Fig. 2

Fig. 7

Fig. 4

Fig. 6

41116_2022_35_Article_IEq564.gif