Abstract
Bacteria isolated from mixed culture originated from rat feces having aflatoxin B1-degrading potency were examined in vitro for degrading aflatoxin B1 after three day incubation. They were composed of four strains of Clostridium sp., three strains of Bacteroides sp. and three strains of Catenabacterium sp. for anaerobes and a strain of Pseudomonas aeruginosa, a strain of Proteus mirabilis, three strains of Streptococcus sp. and a strain of Escherichia coli for aerobes. P. mirabilis Y 2 degraded 50.9% of initial concentration of aflatoxin B1 in 72 hr, three strains of Catenabacterium sp., P. aeruginosa Y 1, Streptococcus sp. Y 5 degraded 25.0_??_35.5 % and the anaerobes other than Catenabacterium sp., Streptococcus sp. Y 4, Streptococcus sp. Y 6 and E. coli Y 8, 12.4-22.0%. Combinations of P. mirabilis Y 2 plus each strain of the Streptococcus sp. degraded 85.6_??_100% of aflatoxin B1 and a combination of all strains of the aerobes degraded 78.8% but all other combinations degraded less than 54.0%. P. aeruginosa Y 1 alone and the combination of P. aeruginosa Y 1 plus P. mirabilis Y 2, that of P. aeruginosa Y 1 plus Streptococcus sp. Y 4 and that of all six strains formed from aflatoxin B1 a very small amount of a new substance with bright-blue fluorescence and Rf value of 0.39 compared with 0.42 for aflatoxin B1 and 0.34 for B2 on thin-layer chromatography plate. Formation of the new fluorescent substance seemed to be concerned with P. aeruginosa Y 1.
