Molecular screening of bacteriocin-producing Bacillus spp. isolated from Soumbala, a fermented food condiment from Parkia biglobosa seeds

Abstract

Bacteriocin-producing Bacillus species have an attractive interest as less studied spore-forming probiotics for food production. In this study, 20 strains of Bacillus were isolated from soumbala, a local fermented food condiment from Burkina Faso. They were characterized based on phenotype, antibacterial activity against Listeria monocytogenes NTCT983 and genotypic analysis by PCR, using specific primers for Bacillus sp., B. subtilis group, B. cereus group, bacteriocin genes, subtilin gene (spaS) and subtilosin gene (sboA). All the isolates were presumptively identified as Bacillus spp. with predominance of B. subtilis species (30%). Out of 20 strains, 11 showed anti-Listeria activity, with inhibition zones ranging from 11.12±0.53 mm (strain B21) to 25.25±0.35 mm (strain F25). PCR profiles revealed that 18 strains belonged to the B. subtilis group while O28 and O46 belonged to the B. cereus species. In addition, 13 strains carried bacteriocin genes, 10 possessed gene sboA and only strain O48 carried gene spaS. This finding highlights the predominance of bacteriocin-producing B. subtilis group species in Soumbala production population. These could be further characterized as probiotic starter cultures carrier for controlled production of high-quality soumbala.