类细菌素高产菌CF10的筛选诱变及发酵条件的研究

Studies on Screening, Mutation and Fermentative Conditions of High Productivity Strain CF10 for Bacteriocinoid Substance

采用纸片法初筛和杯碟法复筛自黄水中分离出一株抗生物质产生菌CF10,经鉴定为布氏乳杆菌(Lactobacillusbuchneri)。在排除酸性末端产物及过氧化氢的干扰后,CF10菌株发酵液对金黄色葡萄球菌(Staphylococcusaureus)和枯草芽孢杆菌(Bacillussubtilis)等革兰氏阳性菌、大肠杆菌(Escherichiacoli)和绿脓杆菌(Pseudomonaspyocyanea)等革兰氏阴性菌、K酵母(SaccharomycescerevisiaeK)和某些真菌有强烈的抑制作用。经紫外线照射(UV)和硫酸二乙酯(DES)多轮复合诱变,CF10发酵液相对效价较未诱变前提高了258%且具有良好的传代稳定性。通过对该菌株产类细菌素发酵条件的研究发现,以2%麦芽糖为碳源、1%大豆蛋白胨加0.5%酵母粉为氮源,培养温度37℃,初始pH6.0～6.5,培养时间48h,接种量1%,厌氧条件下,有微量K+、Mg2+和Mn2+等金属离子存在,CF10所产类细菌素的抑菌活性最高。

CF10, a strain producing inhibitory activity substance, screened out by scrip method and cylinder-dish method from the by product yellow-liquor, was identified as Lactobacillus buchneri. The supernatant of CF10 culture exhibited strong inhibitory activity against the gram-positive bacteria, including Staphylococcus aureus and Bacillus subtilis, and resisted interfering effects of organic acids and hydrogen peroxide. A strong inhibitory activity was also observed against the gram-negative bacteria, such as Escherichia coli and Pseudomonas pyocyanea, Saccharomyces cerevisiae K and some epiphyte. CF10 was complexly mutated by ultraviolet radiation（UV） and diethyl sulphate（DES）. The relative protency of supernatant thus increased 258% with stable inheritance. The culture medium composed of maltose as carbon source and peptone and yeast extract as nitrogen source would enhance, the maximum inhibitory activity of the mutant bacteriocinoid under the optimal conditions： cttlture temperature 37℃, initial pH6.0～6.5 for 48h, 1% inoculation, in anaerobic condition, and presence of K^＋, Mg^2＋ and Mn^2＋.