Incidence of Aspergillus flavus in roasted and raw groundnuts from supermarkets and other vendors in Pietermaritzburg,South Africa and its management using biological control agents

This study was carried out to investigate the incidence of the aflatoxin-producing fungus, Aspergillus flavus in commercially available roasted and raw groundnuts sold by various vendors. Secondly, the study evaluated the antagonistic activity of Bacillus isolates against A. flavus in vitro and in vivo. All the 42 groundnut samples collected from the various vendors were contaminated with A. flavus. There was no significant difference (p > 0.05) in the incidence of A. flavus contamination in roasted and raw groundnut samples. The results of the in vitro bioassay indicated that the Bacillus isolates inhibited the growth of A. flavus ranging from 61 to 76%. In the in vivo study using groundnut kernels, increase in incubation time and concentration of the Bacillus isolates enhanced control of A. flavus. We showed that Bacillus isolates from the phyllosphere of ryegrass has potential as biocontrol agent for the control of A. flavus in groundnuts.