Identification of Bacillus species from ‘iru’, a fermented African locust bean product

Thirty-seven Bacillus isolates were obtained from fermenting locust bean (‘iru’) from three different locations in Nigeria. The isolates were characterized on the basis of biochemical and physiological tests. Thirty-two of the isolates were identified as B. subtilis, two as B. pumilus and three as B. licheniformis. The Bacillus species were sub-divided into strains. Five different strains of B. subtilis and two of B. pumilus were identified. Biochemical tests showed that the strains differ in starch hydrolysis nitrate reduction and methyl red reaction and in their ability to produce acetylmethylcarbinol. They also vary in their patterns of sugar fermentation. This study shows that various strains or dossibly subspecies of B. subtilis are the major Bacillus species involved in the fermentation of the African locust bean (Parkia biglobosa).