ANTI-AFLATOXIGENIC ACTIVITY OF LACTOBACILLUS-CASEI PSEUDOPLANTARUM

Lactobacillus casei pseudoplantarum 371 isolated from a silage inocula nt was found to inhibit aflatoxins B1 and G1 biosynthesis by Aspergill us flavus subsp. parasiticus NRRL 2999, in liquid medium. The inhibito ry activity in the Lactobacillus cell-free supernatant was found to be sensitive to proteolytic. enzymes such as trypsin and alpha-chymotryp sin, but resistant to pepsin. Lab-Lemco tryptone broth (LTB), suppleme nted with 20% of dialyzed protein concentrate of the supernatant, tota lly inhibited the production of aflatoxins B1 and G1. When the protein concentrate was digested with trypsin, the production of aflatoxins B 1 and G1 was restored. The inhibitory activity of the supernatant was inactivated within 10 min at 100 degrees C. A. flavus grown in the Lac tobacillus cell-free supernatant did not produce a mutagenic response in the Salmonella mutagenicity test. However, Lactobacillus casei pseu do-plantarum 371 did not have an effect on aflatoxin production and mo ld growth as measured by ergosterol and plate count, when the organism s were inoculated together on sterile steamed rice.