Bacillus toyonensisbiovar Thuringiensis: an overlooked entomopathogen?

Abstract

Horizontal gene transfer (HGT) significantly influences prokaryotic genome evolution.Bacillus cereusandBacillus thuringiensisare nearly identical genetically, except forB. thuringiensisproducing parasporal crystals. The genes for these crystals, along with other insecticidal proteins (e.g.,vip3), are located on megaplasmids and can be horizontally transferred. Recently, Sauka et al. (2022) reported aBacillus toyonensisstrain that produces parasporal crystals with dual insecticidal activity. This strain was classified asBacillus toyonensisbiovar Thuringiensis (NCBI: txid2923195) following Carroll et al.’s (2020) nomenclature. MisclassifiedB. toyonensisstrains, previously identified asB. thuringiensis(e.g., strain MC28), encodecryandcytgenes toxic to lepidopterous and dipterous insects. Advances in genome sequencing and bioinformatics tools now reduce misidentifications, enabling accurate reclassification in databases like GenBank.