摘要
测定解淀粉芽孢杆菌AF1发酵液的抗菌谱,对发酵液抗MRSA的活性稳定性及抗MRSA机制进行初步探究,为寻找新的抗MRSA化合物提供实验基础。以耐药金葡菌SA46为病原指示菌,不同p H、温度和蛋白酶处理后,考察AF1发酵液剩余抗菌活性。用显微镜和透射电镜观察经发酵液处理后的SA46形态变化,并用凝胶电泳分析SA46的蛋白质和DNA渗漏情况,初步探讨其抗菌机制。结果显示,AF1发酵液具有广谱抗菌活性:不仅对临床耐药金葡菌、一般临床大肠杆菌和金葡菌有很强抑菌作用,同时对大部分试验的植物病原菌也有较好抑菌作用。发酵液在p H 2.0-9.0,4-80℃,120 min后抗菌活性均保持95%以上;并且对蛋白酶K、胃蛋白酶和胰蛋白酶稳定。SA46经发酵液(MIC)处理后,显微镜和透射电镜观察发现其细胞壁受到不同程度破坏;在DNA和蛋白质电泳图上,试验组SA46的DNA和蛋白质条带很清晰,即SA46蛋白质和DNA出现渗漏,而对照组均没有条带出现,初步推断AF1对MRSA的抗菌机理是破坏病原菌的细胞壁来抑制细胞生长的。菌株AF1可作为抗MRSA药物研发的潜在新来源。
This study aims to measure the antimicrobial spectrum of fermentation broth of Bacillus amyloliquefaciens AF1 and to explorethe activity stability and mechanism of anti-MRSA,for providing an experimental basis in seeking new anti-MRSA compounds. The drugresistant S. aureus SA46 was used as indicating pathogen,the rest antimicrobial activities of AF1 fermentation broth were detected after it wasdealed with different p H,temperatures and proteases. The antmicrobial mechanism was studied preliminarily by observing the morphologicchange of SA46 tread with AF1 fermentation broth under both optical microscope and transmission electron microscope,and by detecting theprotein and DNA leakage of treated SA46 with AF1 fermentation broth with SDS-PAGE and agarose gel electrophoresis. The results showedthat AF1 fermentation broth had a broad antimicrobial spectrum. It presented a strong inhibitory ability to all tested clinical drug-resistantStaphylococcus aureus,common clinical Escherichia coli and S. aureus;also it inhibited the most of the tested phytopathogen. The antimicrobialactivity of AF1 fermentation broth remained more than 95% in p H 2.0-9.0 for 120 min from 4 to 80℃,and it was stable when adding protease K,pepsin and trypsin into the broth respectively. The cell walls of SA46 treated by AF1 fermentation broth（MIC）were destroyed at varied levelwhile observed under both optical microscope and transmission electron microscope. Furthermore,the leakage of protein and DNA of treatedSA46 with AF1 fermentation broth were checked by SDS-PAGE and agarose gel electrophoresis. The electrophoretic bands of experimentalgroups were clear,while there was no bands in control groups on both DNA and protein electrophorograms. Thus,a preliminary deductionwas that the cell walls of MRSA were damaged by AF1 fermentation broth. In conclusion,B. amyloliquefaciens AF1 might be developed as apotential new source for the novel anti-MRSA medicines.
作者
杨艳红
余瑛
胡永强
余溪
李青青
YANG Yan-hong YU Ying HU Yong-qiang YU Xi LI Qing-qing(School of Pharmacy ＆ Bioengineering, Chongqing University of Technology, Chongqing 40005)
出处
《生物技术通报》
CAS
CSCD
北大核心
2017年第9期223-230,共8页
Biotechnology Bulletin
基金
重庆市自然科学基金项目(cstc2014jcyj A0211)
关键词
解淀粉芽孢杆菌
抗菌谱
抗MRSA
细胞壁
Bacillus amyloliquefaciens
antimicrobial spectrum
anti-MRSA
cell wall
