地木耳提取物对几种常见微生物的抑菌研究

Antimicrobial Activities of Nostoc commun Extracts on Several Common Microorganisms

采用滤纸扩散法研究了地木耳提取物对五种常见微生物的抑菌作用，以及温度、pH值、紫外光等因素对其抑菌活性的影响。结果表明：地木耳提取物对大肠杆菌、啤酒酵母、枯草芽孢杆菌、白色念珠菌和粘质沙雷细菌五种常见微生物具有较好的抑制作用，其最小抑菌质量浓度为1．5-1mg／mL，但与常用防腐剂柠檬酸的抑菌效果相比较差一些；地木耳提取物分别在121℃高温、紫外光照射5～25min以及pH5．5～7．5的条件下，对大肠杆菌和枯草芽胞杆菌仍具有较好的抑菌效果。

The antimierobial activities of Nostoc commun extracts on five common microorganisms and the influences of temperature, pH value and UV on its antibacterial activities were studied by the method of agar diffusion. The results indicated that the Nostoc commun extracts had obvious inhibition effects on Escherichia coli, Staphylococcus aureus, Bacillus sabtilis, Monilia albican and Serratia marcescens with minimum inhibition concentration （MIC） of 1.5- 1.0 mg/mL , but worse than that of citrate＇s inhibition effects. The antibacterial activity of Nostoc commun extracts on Escherichia coli and Bacillus saStilis was stable through heating at 121℃and UV irradiating for 5-25 min, meanwhile under the condition of pH 5.5-7.5.