中国东海及东太平洋海山区来源抗菌活性海洋微生物的筛选研究

Screening of marine microorganisms with anti-microbial activity from East China Sea and Pacific Ocean

目的研究中国东海及东太平洋区域来源微生物的抗菌活性,意在筛选具有良好抗菌活性的海洋微生物,并初步研究活性菌株代谢产物的结构,为探求新型抗生素提供基础。方法以金黄色葡萄球菌、大肠杆菌和白色念珠菌为指示菌株,采用牛津杯法进行抗菌活性微生物初筛和复筛。通过HPLC-DAD法结合TLC法对活性突出的4株真菌及1株细菌进行活性提取物指纹图谱分析。对广谱抗菌活性菌株WBX-38进行菌种鉴定及活性代谢产物分离纯化,利用核磁共振和质谱等手段对活性化合物进行结构鉴定。采用微量稀释法测定活性化合物的最小抑菌浓度(MIC)。结果与结论从中国东海及东太平洋来源样品中共筛选90株海洋来源菌株,获得抗菌活性菌株16株,4株为海洋细菌,12株为海洋真菌。通过HPLC-DAD法结合TLC法分析,发现5株活性菌株均具有独特的色谱行为。海洋真菌WBX-38通过菌种鉴定,确认为海洋来源曲霉(Aspergillus sp.)。从其发酵液提取物中分离获得1个活性化合物5-hydroxymethylfuran-3-carboxylic acid,该化合物对3种指示菌均具有一定生长抑制活性。

Objective To screen the marine-derived strains with potent antimicrobial activity from East China Sea and the eastern Pacific Ocean,and preliminarily confirm the structures of the bioactive metabolites which aims at laying the foundation for new antibiotics discovery.Methods Staphylococcus aureus,Escherichia coli and Candida albicans were used as indicator bacteria and the antimicrobial activity was screened twice by Oxford cup method.Fingerprint analysis of five active extracts was carried out by HPLC-DAD combined with TLC.The broad-spectrum antimicrobial strain WBX-38 was identified and the active metabolites were isolated and purified.The structures of the active compounds were characterized by means of nuclear magnetic resonance and mass spectroscopy.The minimum inhibitory concentration（MIC）of the active compound was determined by the microdilution method.Results and Conclusion A total of 90 strains were isolated from the East China Sea and the eastern Pacific Ocean,16 strains were screened and identified as active strains.Among them,4 strains were marine bacteria,and12 strains were marine fungi.It was found that five strains had unique chromatographic behavior by HPLC-DAD combined with TLC analysis.And marine-derived fungus WBX-38 was identified as marine-derived Aspergillussp..The fermentation broth was separated and isolated to obtain an active compound 5-hydroxymethylfuran-3-carboxylic acid which had a certain growth inhibitory activity against three kinds of indicator bacteria.