When Beneficial Biofilm on Materials Is Needed: Electrostatic Attachment of Living Bacterial Cells Induces Biofilm Formation

Abstract

Bacterial attachment is crucial in many biotechnological applications, but many important bacterial strains cannot form biofilms. Biofilms can damage materials, and current strategies to manage biofilms are focused on inhibition and removal of biofilm. Biofilm formation is inevitable when materials are exposed to microbes and instead of biofilm prevention, we propose management of microbial composition by formation of biofilms with beneficial microbes. Since bacteria need to overcome a high repulsive force to attach to the surface and later to grow and multiply on it, electrostatic modification of the surfaces of cells or the material by polyelectrolytes (PE) was used in our approach, enabling efficient attachment of viable bacterial cells. Since highly positively charged PEs are known to be bactericidal, they were acetylated to reduce their toxicity, while preserving their net positive charge and ensuring cell viability. In our study bacterial strains were selected according to their intrinsic capability of biofilm formation, their shape variety and cell wall structure. These strains were tested to compare how the artificially prepared vs. natural biofilms can be used to populate the surface with beneficial bacteria. Using an artificial biofilm constructed of the potentially probiotic isolate Bacillus sp. strain 25.2. M, reduced the attachment and induced complete inhibition of E. coli growth over the biofilm. This study also revealed that the modification of the surfaces of cells or material by polyelectrolytes allows the deposition of bacterial cells, biofilm formation and attachment of biofilm non-forming cells onto surfaces. In this way, artificial biofilms with extended stability can be constructed, leading to selective pressure on further colonization of environmental bacteria.

Bradyrhizobium diazoefficiens USDA 110 displays plasticity in the attachment phenotype when grown in different soybean root exudate compounds

“…In another study, altered EPS mutants of B. japonicum 2143 also had no effect on the nodule formation ability of the host (Karr et al, 2000 ). Along with the role of EPS, other bacterial biofilm formation-inducing factors have been reported, such as electrostatic forces and flagella (Rinaudi and Giordano, 2010 ; Deev et al, 2021 ). Lectin-binding data also showed phenotypic plasticity as each RECC had its own lectin-binding barcode profile.…”

Modification of bacterial cells for in vivo remotely guided systems

“…PEI used in this study showed no toxic effects (see Figure 1E and Rybkin et al, 2019 ; van Tatenhove-Pel et al, 2021 ), but it might be toxic if other therapeutically relevant bacteria are used. However, there have been demonstrated approaches to change or modify toxic PEI (see Deev et al, 2021 ), which indicate that the toxicity must be determined in beforehand the LbL is applied for the selected strains.…”

Comparing the antibacterial efficacy and functionality of different commercial alcohol-based sanitizers

“…Biofilm establishment of a surface is often a consequence of a material being inhabited by microbes for a prolonged period [20]. While frequent application of sanitizer on surfaces can greatly reduce the probability of such occurrence, there is still a chance for microbial attachment and biofilm formation on the surface.…”