NON-RIBOSOMAL PEPTIDE ANTIBIOTICS PRODUCTION IN BACILLUS SUBTILISIS GOVERNED BY THE GENETIC DISTANCES BETWEEN BIOFILMS AND THEIR POTENTIAL COMPETITORS

Ecosystems flourish with microbial life; in such environments, bacteria establish complex communities called as biofilms. Bacteria within biofilms produce various antibiotics that play a crucial role in antagonizing a competitor invasion and thus allowing the host to protect its ecological niche.

We asked whether B. subtilis biofilms compete against other rhizosphere dwelling bacilli by measuring the genetic distances between themselves and the potential competitors. Therefore, we tested whether the level of antibiotic production in B. subtilis is influenced by genetic distance of its competitor. To dissect the underlying principles of antibiotic production, we focused on NRP group of antibiotics namely bacillaene, bacilysin, plipastatin and surfactin. Our preliminary results suggested that B. subtilis can sense the genetic distance of its competitor and can alter the level of antibiotic production. We showed that antagonism is weak among highly similar genotypes, and seems to increase with genotypes that are more dissimilar. We now ask how does B. subtilis sense and distinguish its competitors from potential co-operators. This ability of B. subtilis to distinguish between close and distant relatives allows B. subtilis to form successful multispecies biofilms composed of compatible community members.