海洋枯草芽孢杆菌Bs-1产生多种抗真菌活性物质

Antifungal Metabolites from a Marine-derived Bacillus subtilis Bs-1: Production and Partial Characterization

从香港清水湾海域中分离到一株能产生抗酵母样真菌和革兰氏阳性菌抗生素的枯草芽孢杆菌菌株Bs_1。对Bs_1产生抗生素条件的研究表明 ,Bs_1在多种培养基中生长迅速 ,但只在PDB (马铃薯葡萄糖液体 )中产生抗真菌活性物质 ;活性物质粗提液具有良好的耐热性和酸碱度 ,12 1℃加热 15min及在pH 2和pH 10处理 2 4h仍有相当高的活性 ;对Bs_1产抗生素的营养条件和影响的理化因子进行了分析 ;最后用吸附、萃取、离子交换层析和RP_HPLC等技术对此菌的抗菌代谢产物进行纯化 ,结果发现Bs_1在PDB培养基中发酵时至少产生 3种亲水性的抗真菌活性化合物 ,三者在C18反相层析柱上的保留时间差别不大 ,对HPLC纯化后的其中一种化合物结构的初步分析表明 ,该化合物含有共轭双键但无任何氨基酸残基 ,与目前已知的枯草芽孢杆菌产生的抗生素都不相同 ,很可能是一种新的非肽类抗真菌化合物。

The antifungal substances secreted from a marine-derived Bacillus subtilis Bs-1 was studied in the present short report. Bs-1 was isolated from sea water samples of Clear Water Bay of Hong Kong and the PDB culture broth extract of Bs-1 can strongly inhibit the growth of y east-like fungi and G+ bacteria. The study of antibiotic-producing condition o f Bs-1 demonstrated that the growth of Bs-1 in PDB is very rapid and the antibio tic production was detected at the time point of 6 h. Surprisingly, Bs-1 did n ot produce any antifungal metabolites in artificial sea water medium, LB, YPD an d BPY. The activity of the crude extract was very stable after had been heated t o 121 ℃ for 15 min, and pH values from 2 to 10 for 24 h. A procedure was perfor med to purify the antifungal metabolites using orderly adsorption, DEAE-Sephadex A-25 ion-exchange chromatography and HPLC. The result showed that Bs-1 can at l east produce three kinds of antifungal component in PDB. The structure of purifi ed component Ⅱ was preliminary characterized. The results demonstrated that thi s component contained 2 conjugated bonds but did not contain any amino acid re sidue, and was resistance to detergent and digestion of proteinase K, which is d ifferent from the known metabolites from other strains of B. subtilis, sugge sting that it probably is a novel antibiotic.