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영어

Bacilli are widely used as functional probiotics, feed and food additives. In this work, Bacillus sp. LS 1-2, was isolated from Korean transitional soybean paste foods and had similar 16S rRNA of Bacillus sp. of about 98%. LS 1-2 was cultured in citrus-processing-waste containing 5% solid as a culture medium and produced an antimicrobial agent against both of the gram-positives and negatives at adequate culture conditions (pH, Temperature, Culture period and etc). An antimicrobial agent produced by LS 1-2 was purified by alcohol precipitation, C-18 cartridge, YM-10, silica gel open column, prep TLC and prep HPLC. Antimicrobial activity was detected in the fermentation supernatant of LS 1-2. The active substance had more activity through the each purification step. Molecular weight of the antimicrobial agent was lower 10,000Da and it was a hydrophilic compound. The active substance was not sensitive to lipase, proteinase K, amylase, catalase but was affected by pronase E. So this antimicrobial agent was expected as a bacteriocin-like-substance. In order to evaluate its commercial value, the minimum inhibitory concentration of purified antimicrobial agent from Bacillus sp. LS 1-2 was compared with commercialized antimicrobial agents (Colistin, Chlortetracycline, Ampicillin) against Staphylococcus aureus and Escherichia coli O-157.