Natural variations in the biofilm-associated protein BslA from the genus Bacillus

Abstract

BslA is a protein secreted by Bacillus subtilis which forms a hydrophobic film that coats the biofilm surface and renders it water-repellent. We have characterised three orthologues of BslA from Bacillus amyloliquefaciens, Bacillus licheniformis and Bacillus pumilus as well as a paralogue from B. subtilis called YweA. We find that the three orthologous proteins can substitute for BslA in B. subtilis and confer a degree of protection, whereas YweA cannot. The degree to which the proteins functionally substitute for native BslA correlates with their in vitro biophysical properties. Our results demonstrate the use of naturally-evolved variants to provide a framework for teasing out the molecular basis of interfacial self-assembly.

Biofilm Matrixome: Extracellular Components in Structured Microbial Communities

“…which presents as a highly hydrophobic community that resists wetting by water, solvents, and biocides by forming a hydrophobic film that coats the biofilm surface and renders it water-repellent. This remarkable property is conferred by the secreted BslA and orthologous proteins that can self-assemble into an organized lattice at the water-air interface [49,50].…”

Methylene blue active substances in plaque of Bacillus subtilis subsp. subtilis and enrichment by supplemental calcium in culture media

“…Where MBAS activity as SDS equivalents are normalized to molar mass, with SDS having 1 SDS unit per mol, the HPLC-refined protein fraction was determined to comprise 1Á36-2Á35 SDS equivalents per mol. As noted previously, protein BslA is a hydrophobin-like protein exudate of B. subtilis that is recognized to confer surfactant bioactivity (Kobayashi and Megumi 2012;Hobley et al 2017;Morris et al 2017).…”

“…Specifically, surface active lipopeptides such as surfactin, iturin and plipostatin-fengycin, which are each comprised of a cyclic peptide and a fatty acid tail, are known to provide emulsifying bioactivity (Neu 1996;Gundina et al 2015). Additionally, biofilm surface layer protein A, or BslA, is a hydrophobin-like protein exudate of B. subtilis that provides surfactant bioactivity and contributes to biofilm surface hydrophobicity (Kobayashi and Megumi 2012;Hobley et al 2017;Morris et al 2017).…”

Bacillus subtilis, the model Gram‐positive bacterium: 20 years of annotation refinement

“…Biofilms form highly hydrophobic communities that resist wetting but also solvents and biocides. Hydrophobicity is essentially caused by secreted protein BslA with a small contribution of BslB(YweA), its paralogue (Morris et al ., 2017), via production of a leaf/petal‐like hydrophobic behaviour (Werb et al ., 2017). In the biofilm, synthesis of BslA is tightly regulated and the resultant protein is secreted into the extracellular environment where it forms a barrier allowing the B. subtilis cells to shelter under a ‘protein raincoat’ (Arnaouteli et al ., 2016).…”