Biofilm Formation and Regulation in Bacillus subtilis Systems

Bacillus subtilis establishes multicellular communities known as biofilms through a finely tuned developmental programme that integrates environmental cues, cell–cell signalling and metabolic status. Initiation of biofilm formation involves a switch from motility to matrix production, orchestrated by the Spo0A phosphorelay and opposed by the repressor SinR. Cells differentiate into distinct subpopulations, including matrix‐producing cells that secrete extracellular polymeric substances (EPS) and amyloid fibres, motile cells, and spores. Two‐component systems and quorum sensing peptides further modulate matrix assembly, while factors such as iron availability and oxidative stress feed into regulatory circuits. The resulting extracellular matrix, comprising polysaccharides, protein fibres and surface‐active lipopeptides, provides structural cohesion, protection from environmental insults and capacity for surface colonisation. Recent advances reveal the importance of spatiotemporal metabolite exchange during community expansion, the role of surfactin not only in motility inhibition but also in competitive interactions, and the function of specialised pigments in mitigating oxidative damage. Insights into the interplay between gene regulation, metabolism and interspecies interactions underscore the global significance of Bacillus subtilis biofilms in agriculture, bioremediation and industrial processes.

Research from Nature Portfolio

Simultaneous live‐cell microscopy and spatiotemporal transcriptomic profiling during B. subtilis swarm development uncovered how gene expression patterns correlate with collective behaviours and phenotypic subpopulations. Early generations deposit metabolites that fuel the migration of later cells, revealing a cross‐feeding mechanism essential for coordinated surface expansion. This approach highlights the dynamic interplay between metabolic exchange and community architecture in biofilms.

In a co‐culture evolution study with the fungus Aspergillus niger, adaptation of B. subtilis selected mutations in the DegS–DegU two‐component system that boost surfactin production and accelerate surface spreading. Enhanced surfactin secretion not only inhibits fungal hyphal growth by inducing cell wall stress but also promotes competitive colonisation, illustrating how interkingdom interactions shape biofilm regulatory networks.

Biofilm Formation and Regulation in Bacillus subtilis Systems publication trend

The graph below shows the total number of articles in biofilm formation and regulation in bacillus subtilis systems across all publications each year (not limited to Nature Index journals).

Technical terms

Biofilm: A surface‐attached microbial community encased in a self‐produced extracellular matrix.

Extracellular matrix: A composite scaffold of polysaccharides, proteins and lipids that embeds cells within a biofilm.

Exopolysaccharide (EPS): High‐molecular‐weight sugar polymers secreted by cells to form part of the biofilm matrix.

Surfactin: A cyclic lipopeptide that reduces surface tension, modulates motility and influences biofilm architecture.

Two‐component system: A signal transduction mechanism comprising a sensor kinase and response regulator that adjusts gene expression to environmental stimuli.

Pulcherrimin: An iron‐binding pigment produced as pulcherriminic acid, formed extracellularly into a red complex that protects biofilm cells from oxidative damage.

Spatiotemporal transcriptomics: A technique to measure gene expression patterns with both spatial and temporal resolution within microbial communities.

References

1. Simultaneous spatiotemporal transcriptomics and microscopy of Bacillus subtilis swarm development reveal cooperation across generations. Nature Microbiology (2023).
2. Enhanced surface colonisation and competition during bacterial adaptation to a fungus. Nature Communications (2024).
3. Pulcherrimin protects Bacillus subtilis against oxidative stress during biofilm development. npj Biofilms and Microbiomes (2023).
4. Metabolic Remodeling during Biofilm Development of Bacillus subtilis. mBio (2019).