Fungicidal effect of bacteriocins harvested from Bacillus spp.

Aims: This study investigated the ability of bacteriocins isolated from Bacillus spp. (Bacillus species) to inhibit four different yeast isolates obtained from common food products (nono, yoghurt, ogi and cheese) commonly consumed by Nigerians with minimal heat treatment. Methodology and results: Forty-five Bacillus spp. was isolated and identified from common food products using cultural, morphological, physiological and biochemical characteristics. These isolates were tested for antimicrobial activity against Salmonella enteritidis (3), Micrococcus luteus (1) and Staphylococcus aureus (2). Eight bacteriocin producing strains were identified from an over- night broth culture centrifugated at 3500 revolutions for five minutes. Fungicidal effects of these bacteriocins were tested against four yeast strains using the Agar Well Diffusion method. The bacteriocins produced wide zones of inhibition ranging from 5.9±0.000 to 24.00±0.000 mm against the 4 yeast strains tested. There was a significant difference (at p 0.05) between the yeast organisms and the bacteriocins from the Bacillus spp. Conclusion, significance and impact of study: The study reveals the antifungal property of bacteriocins from Bacillus spp. and serves therefore as a base for further studies in its use in the control of diseases and extension of shelf-life of products prone to fungi contamination.