본 연구에서는 숙성된 된장으로부터 분리된 유산균에 의한 aflatoxin B1의 결합 정도를 배양조건에 따라 측정하였고, 물리화학적 처리조건이 aflatoxin B₁에 대한 유산균 세포의 결합력에 미치는 영향을 살펴보았다. Enterococcus faecium DJ22, Lactobacillus fermentum DJ35, Lactobacillus rhamnosus DJ42 및 Lactobacillus pentosus DJ47는 19.3??52.1% 정도의 aflatoxin B1 결합 효과를 나타내어 균종에 따라 결합력에 차이가 있었다. 하지만 E. faecalis DJ14, Lactobacillus panis DJ29 및 Pediococcus halophilus DJ50 균주는 aflatoxin B₁에 대한 결합력을 나타내지 않았다. Aflatoxin B₁에 대한 유산균의 결합력과 결합속도는 독소의 농도, 반응시간 및 온도와 초기 세포수 등의 배양 조건에 따라 유의한 차이가 있었다. Aflatoxin B₁의 결합력은 세척 횟수에 따라 현저하게 감소하였고, 감소율은 살아있는 세포와 가열 처리한 세포에서 비슷하게 나타났다. 가열, 산성 pH, α-amylase, protease, lysozyme 혹은 sodium metaperiodate의 처리에 의해 결합력이 유의하게 감소된 것으로 보아 주로 세포벽에 존재하는 당이나 단백질에 aflatoxin B₁이 결합되며, urea의 처리에 의해 결합력에 낮아지는 것은 이들 사이에는 소수성 결합이 작용하는 것으로 추정되었다.
The purpose of this study was to investigate the aflatoxin B1 binding of lactic acid bacteria (LAB) isolated from Korean traditional soybean paste and to evaluate the effect of incubation conditions and physico-chemical factors on the binding ability of LAB to this mutagen. The amount of aflatoxin B1 bound by Enterococcus faecium DJ22, Lactobacillus fermentum DJ35, Lactobacillus rhamnosus DJ42, and Lactobacillus pentosus DJ47 was strain specific with the percent bound ranging from 19.3% to 52.1%. However, Enterococcus faecalis DJ14, Lactobacillus panis DJ29, and Pediococcus halophilus DJ50 strains did not exhibit any of the binding ability to aflatoxin B1. For most strains, the binding ability was significantly affected by the environmental conditions such as the aflatoxin B1 level, incubation time and temperature, and the initial cell count of LAB. The stability of the aflatoxin B1-bacteria complexes was significantly more unstable after washing. In addition, the binding stability between viable and nonviable cells was not statistically significant. Treatment with heating, acidic pH, α-amylase, protease, lysozyme, or sodium metaperiodate caused a significant (P<0.05) decrease in aflatoxin B1 binding for the tested strains, suggesting that carbohydrates or proteins in the cell walls may be involved in aflatoxin B1 binding ability. Since the aflatoxin B1 binding of LAB was significantly reduced (P<0.05) by the pretreatment of the urea, the binding force observed in this study may have resulted from hydrophobic interaction.