Back to Search Start Over

Negative Interplay between Biofilm Formation and Competence in the Environmental Strains of Bacillus subtilis

Authors :
Qianxuan She
Evan Hunter
Yuxuan Qin
Samantha Nicolau
Eliza A. Zalis
Hongkai Wang
Yun Chen
Yunrong Chai
Source :
mSystems, Vol 5, Iss 5 (2020)
Publication Year :
2020
Publisher :
American Society for Microbiology, 2020.

Abstract

ABSTRACT Environmental strains of the soil bacterium Bacillus subtilis have valuable applications in agriculture, industry, and biotechnology; however, environmental strains are genetically less accessible. This reduced accessibility is in sharp contrast to laboratory strains, which are well known for their natural competence, and a limitation in their applications. In this study, we observed that robust biofilm formation by environmental strains of B. subtilis greatly reduced the frequency of competent cells in the biofilm. By using model strain 3610, we revealed a cross-pathway regulation that allows biofilm matrix producers and competence-developing cells to undergo mutually exclusive cell differentiation. We further demonstrated that the competence activator ComK represses the key biofilm regulatory gene sinI by directly binding to the sinI promoter, thus blocking competent cells from simultaneously becoming matrix producers. In parallel, the biofilm activator SlrR represses competence through three distinct mechanisms involving both genetic regulation and cell morphological changes. Finally, we discuss the potential implications of limiting competence in a bacterial biofilm. IMPORTANCE The soil bacterium Bacillus subtilis can form robust biofilms, which are important for its survival in the environment. B. subtilis also exhibits natural competence. By investigating competence development in B. subtilis in situ during biofilm formation, we reveal that robust biofilm formation often greatly reduces the frequency of competent cells within the biofilm. We then characterize a cross-pathway regulation that allows cells in these two developmental events to undergo mutually exclusive cell differentiation during biofilm formation. Finally, we discuss potential biological implications of limiting competence in a bacterial biofilm.

Details

Language :
English
ISSN :
23795077
Volume :
5
Issue :
5
Database :
Directory of Open Access Journals
Journal :
mSystems
Publication Type :
Academic Journal
Accession number :
edsdoj.3ab0ca95c48483c943ca03bb485989b
Document Type :
article
Full Text :
https://doi.org/10.1128/mSystems.00539-20