Strain-level diversity of secondary metabolism in the biocontrol species Aneurinibacillus migulanus.

Aneurinibacillus migulanus strains Nagano and NCTC 7096 show potential in biocontrol against fungal and fungus-like plant pathogens, including a wide range of Ascomycota, Basidiomycota, and Oomycetes. Differences in terms of the range of pathogens that each strain inhibits, however, suggested that production of a single antibiotic cyclic peptide, gramicidin S (GS), by the two strains, is not the sole mechanism of inhibition. The availability of four sequenced genomes of Aneurinibacillus prompted us to apply genome mining techniques to identify the bioactive potential of A. migulanus and to provide insights into the secondary metabolite arsenal of the genus Aneurinibacillus. Up to eleven secondary metabolite biosynthetic gene clusters were present in the three Aneurinibacillus species. Biosynthetic gene clusters specifying bacteriocins, microcins, non-ribosomal peptides, polyketides, terpenes, phosphonates, lasso peptides and linaridins were identified. Chitinolytic potential and iron metabolism regulation were also investigated. With increasing numbers of biocontrol bacterial genomes being sequenced and mined, the use of approaches similar to those described in this paper will lead to an increase in the numbers of environmentally friendly natural products available to use against plant diseases.