【目的】筛选产广谱、高效抑菌活性物质的海洋放线菌,为新型抗生素的开发奠定基础。【方法】采用琼脂块法初筛,打孔扩散法复筛,以金黄色葡萄球菌、大肠埃希氏菌、枯草芽孢杆菌和单核细胞增生李斯特菌为指示菌从海泥样品中筛选目标菌株;...【目的】筛选产广谱、高效抑菌活性物质的海洋放线菌,为新型抗生素的开发奠定基础。【方法】采用琼脂块法初筛,打孔扩散法复筛,以金黄色葡萄球菌、大肠埃希氏菌、枯草芽孢杆菌和单核细胞增生李斯特菌为指示菌从海泥样品中筛选目标菌株;利用20种指示菌株考查Y10、Y11、Y15、Y16和Y21的抑菌谱;通过形态观察和16S r RNA基因序列分析确定菌株分类地位;以单核细胞增生李斯特菌的OD600值为指标探讨Y15抑菌活性物质对该菌的作用方式;以抑菌活性为指标研究Y15抑菌活性物质的理化性质。【结果】共分离12株具抑菌活性的海洋放线菌,其中Y15抑菌谱最广,对20种指示菌株中的18种具有抑菌活性,并且在4种培养基中均能产生抑菌活性物质。16S r RNA基因序列分析表明Y15属于小单孢菌属,并与Micromonospora endolithica亲缘关系最近。Y15抑菌活性物质在144 h达到最高值为480 AU/m L,在168-216 h保持平衡为320 AU/m L。Y15抑菌活性物质对单核细胞李斯特菌作用方式为杀菌。Y15抑菌活性物质在-20-60°C抑菌活性保持稳定,在80-120°C活性逐渐下降,但在120°C处理30 min仍保留37.5%的活性;在p H 7.0-10.0抑菌活性稳定,在p H 2.0-6.0和p H 11.0-12.0抑菌活性均有所损失;Y15抑菌活性物质对紫外和4种酶(蛋白酶K、胰蛋白酶、木瓜蛋白酶和α-淀粉酶)处理均保持稳定,表明活性物质为非蛋白和非多肽类的抑菌物质。【结论】Y15产生的活性物质具有良好的抑菌谱和抑菌活性,且较为稳定,具有较高的应用价值。展开更多
[Objective] The screening method and the pathogenic function of pathogenic bacteria X46（Micromonospora）of crabgrass was studied.[Method] Improved Gaoshi No.I medium was adopted to isolate a strain of pathogenic bact...[Objective] The screening method and the pathogenic function of pathogenic bacteria X46（Micromonospora）of crabgrass was studied.[Method] Improved Gaoshi No.I medium was adopted to isolate a strain of pathogenic bacteria X46 of crabgrass from the rhizosphere soil of crabgrass and barnyardgrass,the optimal toxin production condition was determined,and the preliminary assessment of its security was conducted.[Result] Pathogenic bacteria X46（Micromonospora）of crabgrass was identified to be Micromonospora.When the liquid volume of 300 ml flask was 30 ml,initial pH was 6.0-6.5,inoculation amount was 10%,fermentation was conducted at 180 r/min,28 ℃ for 120 h,the production amount of toxin in improved Gaoshi No.I medium was the largest,these were the optimum culture condition.The bacteria had significant promotion effect on the growth of maize,tomato and soybean,which had slight inhibition effect on wheat growth and significant inhibition effect on cucumber growth.[Conclusion] X46 is a potential strain that can be developed as the biological herbicide in North China.展开更多
弹性蛋白酶抑制剂Fw 99468是小单孢菌F IM 99468发酵产生的次级代谢产物。在37℃,0.05M T ris-HC l(pH 7.6)缓冲液中,它对弹性蛋白酶具有抑制作用。在抑制剂浓度较小(0mM^0.013mM)的情况下,抑制剂与酶的结合呈直线关系,随着抑制剂浓度...弹性蛋白酶抑制剂Fw 99468是小单孢菌F IM 99468发酵产生的次级代谢产物。在37℃,0.05M T ris-HC l(pH 7.6)缓冲液中,它对弹性蛋白酶具有抑制作用。在抑制剂浓度较小(0mM^0.013mM)的情况下,抑制剂与酶的结合呈直线关系,随着抑制剂浓度的提高,抑制活力曲线则出现漂移。根据D ixon图和L inew eaver-Burk图的研究,该抑制剂对弹性蛋白酶呈竞争性抑制,抑制常数Ki=3.5×10-5M。展开更多
文摘【目的】筛选产广谱、高效抑菌活性物质的海洋放线菌,为新型抗生素的开发奠定基础。【方法】采用琼脂块法初筛,打孔扩散法复筛,以金黄色葡萄球菌、大肠埃希氏菌、枯草芽孢杆菌和单核细胞增生李斯特菌为指示菌从海泥样品中筛选目标菌株;利用20种指示菌株考查Y10、Y11、Y15、Y16和Y21的抑菌谱;通过形态观察和16S r RNA基因序列分析确定菌株分类地位;以单核细胞增生李斯特菌的OD600值为指标探讨Y15抑菌活性物质对该菌的作用方式;以抑菌活性为指标研究Y15抑菌活性物质的理化性质。【结果】共分离12株具抑菌活性的海洋放线菌,其中Y15抑菌谱最广,对20种指示菌株中的18种具有抑菌活性,并且在4种培养基中均能产生抑菌活性物质。16S r RNA基因序列分析表明Y15属于小单孢菌属,并与Micromonospora endolithica亲缘关系最近。Y15抑菌活性物质在144 h达到最高值为480 AU/m L,在168-216 h保持平衡为320 AU/m L。Y15抑菌活性物质对单核细胞李斯特菌作用方式为杀菌。Y15抑菌活性物质在-20-60°C抑菌活性保持稳定,在80-120°C活性逐渐下降,但在120°C处理30 min仍保留37.5%的活性;在p H 7.0-10.0抑菌活性稳定,在p H 2.0-6.0和p H 11.0-12.0抑菌活性均有所损失;Y15抑菌活性物质对紫外和4种酶(蛋白酶K、胰蛋白酶、木瓜蛋白酶和α-淀粉酶)处理均保持稳定,表明活性物质为非蛋白和非多肽类的抑菌物质。【结论】Y15产生的活性物质具有良好的抑菌谱和抑菌活性,且较为稳定,具有较高的应用价值。
基金Supported by Funded Project in Department of Education,Hebei Province:Research on Microorganism Herbicide of Crabgrass Pathogenic bacteria(No.Z2007443)~~
文摘[Objective] The screening method and the pathogenic function of pathogenic bacteria X46（Micromonospora）of crabgrass was studied.[Method] Improved Gaoshi No.I medium was adopted to isolate a strain of pathogenic bacteria X46 of crabgrass from the rhizosphere soil of crabgrass and barnyardgrass,the optimal toxin production condition was determined,and the preliminary assessment of its security was conducted.[Result] Pathogenic bacteria X46（Micromonospora）of crabgrass was identified to be Micromonospora.When the liquid volume of 300 ml flask was 30 ml,initial pH was 6.0-6.5,inoculation amount was 10%,fermentation was conducted at 180 r/min,28 ℃ for 120 h,the production amount of toxin in improved Gaoshi No.I medium was the largest,these were the optimum culture condition.The bacteria had significant promotion effect on the growth of maize,tomato and soybean,which had slight inhibition effect on wheat growth and significant inhibition effect on cucumber growth.[Conclusion] X46 is a potential strain that can be developed as the biological herbicide in North China.
