AUTHOR=Müller Susanne , DeLeon Orlando , Atkinson Samantha N. , Saravia Fatima , Kellogg Stephanie , Shank Elizabeth A. , Kirby John R. 

TITLE=Thiocillin contributes to the ecological fitness of Bacillus cereus ATCC 14579 during interspecies interactions with Myxococcus xanthus

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1295262

DOI=10.3389/fmicb.2023.1295262

ISSN=1664-302X

ABSTRACT=<p>The soil-dwelling delta-proteobacterium <italic>Myxococcus xanthus</italic> is a model organism to study predation and competition. <italic>M. xanthus</italic> preys on a broad range of bacteria mediated by lytic enzymes, exopolysaccharides, Type-IV pilus-based motility, and specialized metabolites. Competition between <italic>M. xanthus</italic> and prey bacterial strains with various specialized metabolite profiles indicates a range of fitness, suggesting that specialized metabolites contribute to prey survival. To expand our understanding of how specialized metabolites affect predator–prey dynamics, we assessed interspecies interactions between <italic>M. xanthus</italic> and two strains of <italic>Bacillus cereus</italic>. While strain ATCC 14579 resisted predation, strain T was found to be highly sensitive to <italic>M. xanthus</italic> predation. The interaction between <italic>B. cereus</italic> ATCC 14579 and <italic>M. xanthus</italic> appears to be competitive, resulting in population loss for both predator and prey. Genome analysis revealed that ATCC 14579 belongs to a clade that possesses the biosynthetic gene cluster for production of thiocillins, whereas <italic>B. cereus</italic> strain T lacks those genes. Further, purified thiocillin protects <italic>B. cereus</italic> strains unable to produce this specialized metabolite, strengthening the finding that thiocillin protects against predation and contributes to the ecological fitness of <italic>B. cereus</italic> ATCC 14579. Lastly, strains that produce thiocillin appear to confer some level of protection to their own antibiotic by encoding an additional copy of the L11 ribosomal protein, a known target for thiopeptides. This work highlights the importance of specialized metabolites affecting predator–prey dynamics in soil microenvironments.</p>