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

Abstract

Background: 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. Results: 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). Conclusions: 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.

Biofilm-Forming Ability and Effect of Sanitation Agents on Biofilm-Control of Thermophile Geobacillus sp. D413 and Geobacillus toebii E134

“…In another study, Izano et al (2008) reported that DNase I prevented biofilm formation of S. aureus and S. epidermidis. DNase I began to dissolve biofilms of Bacillus subtilis after 3 h, whereas the biofilms dissolved at the slight degree at the 24 and 48 h (Peng et al 2020). In addition, Peng et al (2020) reported that young biofilms were easily disturbed by DNase I, whereas the latter was not effective against aged biofilms.…”

“…DNase I began to dissolve biofilms of Bacillus subtilis after 3 h, whereas the biofilms dissolved at the slight degree at the 24 and 48 h (Peng et al 2020). In addition, Peng et al (2020) reported that young biofilms were easily disturbed by DNase I, whereas the latter was not effective against aged biofilms. On the contrary, this study determined that aged biofilms of Geobacillus isolates were markedly affected by DNase I.…”

Topography and Expansion Patterns at the Biofilm-Agar Interface in Bacillus subtilis Biofilms

“…The matrix in which bacterial cells are embedded consists of exopolysaccharides and other types of biomolecules such as lipids, proteins and nucleic acids. The interaction between components of the extracellular matrix was shown to play a role in the three-dimensional structuring of biofilms [ 4 , 5 ]. In B. subtilis biofilms, presence of specific biomaterials such as calcite minerals [ 6 ] and amyloid fibers [ 7 ] was shown to provide structural integrity and “robustness”.…”

Novel method to achieve crystallinity of calcite by Bacillus subtilis in coupled and non-coupled calcium-carbon sources

“…Those group, related to main EPS components (exopolysaccharides and proteins) play a key role in BCC formation (Azulay and Chai 2019). P content may be related to extracellular DNA usually present in EPS (Peng et al 2020).…”