Biodiversity of predominant Bacillus isolated from afitin, iru and sonru at different fermentation time

Two hundred (200) presumptive isolates of Bacillus collected at different fermentation time from spontaneous fermented samples of afitin, iru and sonru produced in three different regions of Benin were identified at species and strains levels. ITS-PCR-RFLP revealed that 79% of the isolates were really identified as Bacillus, 5% as Staphylococcus and 16% as unidentified bacteria. The 16S rDNA sequencing showed that 74.7% of the Bacillus belonged to the B. subtilis group and 25.3% to the B. cereus group. Additional biochemical tests and API 50 CHB system applied to 50 isolates randomly selected from the B. subtilis group divided the latter into 80% typical B. subtilis and 20% typical B. licheniformis, which showed different PFGE-RFLP band patterns. Strains belonging to the B. cereus group were differentiated by PCR with specific primers BCW1F and BCW1R and specific enzymes EcoRI, Sau3AI and RsaI. All strains of the B. cereus group, except one, were found to be typical B. cereus. This work showed the predominance of B. subtilis in afitin, iru and sonru along the fermentation process. Keywords: Afitin, Iru, Sonru, Fermentation, Bacillus. International Journal of Biological and Chemical Sciences Vol. 1 (3) 2007: pp. 211-22