Isolation of Antifungal Lactic Acid Bacteria (LAB) from “Kunu” against Toxigenic Aspergillus flavus

The antifungal activity of isolated lactic acid bacteria (LAB) from a locally fermented cereal, "Kunu", was tested against toxigenic Aspergillus flavus. The liquid refreshment, "Kunu", was prepared under hygienic condition using millet, sorghum, and the combination of the two grains. The antifungal potential of isolated LAB against toxigenic A. flavus was carried out using both in vitro and in vivo antifungal assays. The LAB count from prepared "Kunu" ranged from 2.80 ×104 CFU/mL to 4.10×104 CFU/mL and Lactobacillus plantarum, Lactobacillus delbrueckii, Lactobacillus fermentum, Pediococcus acidilactici, and Leuconostoc mesenteroides were the isolated bacteria. Inhibitory zones exhibited by LAB against toxigenic A. flavus ranged from 5.0 mm to 20.0 mm. The albino mice infected with toxigenic A. flavus showed sluggishness, decrease in body weight, distortion of hair, and presence of blood in their stool, while those treated with LAB after infection were recovered and active like those in control groups. Except for the white blood cell that was increased in the infected mice as 6.73 mm3, the packed cell volume, hemoglobin, and red blood cell in infected animals were significantly reduced (P<0.05) to 29.28%, 10.06%, and 4.28%, respectively, when compared to the treated mice with LAB and control groups. The antifungal activity of LAB against toxigenic A. flavus can be attributed to the antimicrobial metabolites. These metabolites can be extracted and used as biopreservatives in food products to substitute the use of chemical preservatives that is not appealing to consumers due to several side effects.