The exopolysaccharide–eDNA interaction modulates 3D architecture of Bacillus subtilis biofilm

BMC Microbiology

article

Peng, Na¹  Cai, Peng¹  Mortimer, Monika²  Wu, Yichao¹  Gao, Chunhui¹  Huang, Qiaoyun¹ 

[1] State Key Laboratory of Agricultural Microbiology, College of Resources of Environment, Huazhong Agricultural University;Bren School of Environmental Science and Management and Earth Research Institute, University of California

关键词: Extracellular DNA (eDNA);    Exopolysaccharide (EPS);    Bacillus subtilis;    Biofilm formation;   

DOI  :  10.1186/s12866-020-01789-5

学科分类：放射科、核医学、医学影像

来源: BioMed Central

【 摘 要 】

Bacterial biofilms are surface-adherent microbial communities in which individual cells are surrounded by a self-produced extracellular matrix of polysaccharides, extracellular DNA (eDNA) and proteins. Interactions among matrix components within biofilms are responsible for creating an adaptable structure during biofilm development. However, it is unclear how the interactions among matrix components contribute to the construction of the three-dimensional (3D) biofilm architecture. DNase I treatment significantly inhibited Bacillus subtilis biofilm formation in the early phases of biofilm development. Confocal laser scanning microscopy (CLSM) and image analysis revealed that eDNA was cooperative with exopolysaccharide (EPS) in the early stages of B. subtilis biofilm development, while EPS played a major structural role in the later stages. In addition, deletion of the EPS production gene epsG in B. subtilis SBE1 resulted in loss of the interaction between EPS and eDNA and reduced the biofilm biomass in pellicles at the air-liquid interface. The physical interaction between these two essential biofilm matrix components was confirmed by isothermal titration calorimetry (ITC). Biofilm 3D structures become interconnected through surrounding eDNA and EPS. eDNA interacts with EPS in the early phases of biofilm development, while EPS mainly participates in the maturation of biofilms. The findings of this study provide a better understanding of the role of the interaction between eDNA and EPS in shaping the biofilm 3D matrix structure and biofilm formation.

【 授权许可】

CC BY|CC0