title: Bacillaene and sporulation protect Bacillus subtilis from predation by Myxococcus xanthus.
abstract: Myxococcus xanthus and Bacillus subtilis are common soil-dwelling bacteria that produce a wide range of secondary metabolites and sporulate under nutrient-limiting conditions. Both organisms affect the composition and dynamics of microbial communities in the soil. However, M. xanthus is known to be a predator, while B. subtilis is not. A screen of various prey led to the finding that M. xanthus is capable of consuming laboratory strains of B. subtilis, while the ancestral strain, NCIB3610, was resistant to predation. Based in part on recent characterization of several strains of B. subtilis, we were able to determine that the pks gene cluster, which is required for production of bacillaene, is the major factor allowing B. subtilis NCIB3610 cells to resist predation by M. xanthus. Furthermore, purified bacillaene was added exogenously to domesticated strains, resulting in resistance to predation. Lastly, we found that M. xanthus is incapable of consuming B. subtilis spores even from laboratory strains, indicating the evolutionary fitness of sporulation as a survival strategy. Together, the results suggest that bacillaene inhibits M. xanthus predation, allowing sufficient time for development of B. subtilis spores.
authors.affiliation: Department of Microbiology, University of Iowa, Iowa City, Iowa, USA.
authors.forename: Susanne
authors.initials: S
authors.lastname: Müller
authors.affiliation: Department of Microbiology, University of Iowa, Iowa City, Iowa, USA.
authors.forename: Sarah N
authors.initials: SN
authors.lastname: Strack
authors.affiliation: Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
authors.forename: B Christopher
authors.initials: BC
authors.lastname: Hoefler
authors.affiliation: Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Straight
authors.affiliation: Department of Biology, Indiana University, Bloomington, Indiana, USA.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Kearns
authors.affiliation: Department of Microbiology, University of Iowa, Iowa City, Iowa, USA john-kirby@uiowa.edu.
authors.forename: John R
authors.initials: JR
authors.lastname: Kirby
mesh_terms: D000890:Anti-Infective Agents / Q000378:metabolism*; D001412:Bacillus subtilis / Q000254:growth & development* / Q000378:metabolism*; D050296:Microbial Viability; D016941:Myxococcus xanthus / Q000378:metabolism*; D011090:Polyenes / Q000378:metabolism*; D013171:Spores, Bacterial / Q000254:growth & development*
chemical_list: D000890:Anti-Infective Agents; D011090:Polyenes; C096634:bacillaene