Bacillus subtilis Strain ka15: a potent starter isolated from kawal, a fermented condiment

Kawal is a fermented condiment obtained from the natural alkaline fermentation of Senna obtusifolia leaves. The Bacillus strain was isolated from a kawal sample purchased at the Abeche market in Tchad. For genomic DNA extraction, the strain was grown on LB agar. A single colony was selected and grown in LB broth until it reached an optical density of 0.8 at 600 nm (OD600), before being subjected to genomic DNA extraction using the Wizard Genomic DNA Purification kit (Promega). Genomic DNA concentration was determined using an Invitrogen Qubit 4 fluorometer, and sequencing libraries were generated using the Nextera XT DNA library preparation kit (Illumina), according to the manufacturer's instructions. Sequencing was performed using Illumina's NovaSeq platform. The strain is capable of inhibiting the growth of kawal pathogens, including bacteria and molds. It also has probiotic potential and could serve as a starter for controlled kawal fermentation.