Fruiting body formation by Bacillus subtilis

Area of Science:

• Microbiology
• Cellular Differentiation
• Biofilm Formation

Background:

• Spore formation in Bacillus subtilis is a model for cellular differentiation, typically studied at the single-cell level.
• Previous research has not fully explored the spatial organization of sporulation within complex microbial communities.

Purpose of the Study:

• To investigate the spatial organization of Bacillus subtilis spore formation within biofilms.
• To identify genetic and phenotypic factors contributing to this spatial organization.
• To compare sporulation in natural isolates versus laboratory strains.

Main Methods:

• Analysis of Bacillus subtilis in structured, surface-associated communities (biofilms).
• Observation of cellular differentiation into chains and aerial structures (fruiting bodies).
• Genetic analysis of regulatory and production genes involved in fruiting body formation.

Main Results:

• Spore formation exhibits unexpected spatial organization within biofilms, forming aerial structures (fruiting bodies).
• Fruiting body formation is dependent on specific regulatory genes and genes for exopolysaccharide and surfactin production.
• Natural isolates demonstrated robust aerial structure formation, unlike laboratory strains, indicating a loss of multicellular traits in domesticated strains.

Conclusions:

• Bacillus subtilis spore formation in biofilms is a multicellular process with distinct spatial organization.
• Multicellular behaviors, including aerial structure formation, may have been lost in laboratory strains during domestication.
• Other microbial differentiation processes may also exhibit multicellular spatial organization when studied in natural isolates.