Antifungal activity and aflatoxin binding ability of Lactobacillus species isolated from lamb and goatling stomach mucus

摘要

Eight isolates from lamb and goatling stomach mucus belonging to Lactobacillus reuteri, Lb. plantarum, Lb. mucosae, Lb. murinus and a dairy strain Lb. reuteri CCM 3625 were characterized for their antifungal activity. The ability of five selected strains to bind aflatoxin B-1 was determined in vitro by high-performance liquid chromatography. Impact of pH, inactivated Escherichia coli and additives, namely, phenylalanine, tyrosine and alpha-ketoglutarate, on the antifungal activity of the strains was evaluated. Production of phenyllactic acid and 4-hydroxyphenyllactic acid was measured in the cell-free supernatant with optimized composition. All tested strains showed antifungal activity against tested fungi (7.4-43.0 % of growth inhibition). The antifungal activity was enhanced at pH 4.0 in most cases. Supplementation of the medium by phenylalanine, tyrosine and a-ketoglutarate increased the antifungal activity against Aspergillus flavus and Rhizopus oryzae. The best producer of phenyllactic acid was Lb. plantarum KG4 (0.7400 +/- 0.0217 mmol.l(-1)). The tested strains bound 10.8-66.7 % of aflatoxin B-1 present in the sample. A combination of both the antifungal activity and activity to bind aflatoxin B-1 indicates the potential of the strains to eliminate toxins and fungal contamination of food and feed as well as other substances like heavy metals in practice.