利用平板对峙法,从实验室保藏的20株蛹虫草菌株中筛选出抗菌效果较强的CF2菌株;采用蒸馏水和95%乙醇作为提取剂,提取液作用于指示菌,发现水溶性提取物抑菌效果明显优于脂溶性提取物;经Sevage法脱蛋白后抑菌效果消失,初步分析该活性物质为蛋白质。在90℃水浴10 min后抑菌物质才失去活性,表明该抑菌物质对温度不敏感。对芽孢杆菌和酵母菌的抑制率分别为97.1%、30.9%,对黑曲霉菌落生长抑制率为18.4%。
By using plate confrontation, the strain CF2 was screened out with a stronger antibacterial activity from 20 strains of Cordyceps militaris. The results showed that water extraction had better inhibitory activity than the extraction which extracted by 95% ethanol. The inhibitory effect disappeared after deproteining by the method of Sevage, and maybe the substance is protein. Not until the supernatant culture heated for 10 min at 90℃ does the inhibitory activity disappear, thus the extraction was not sensitive to temperature. The inhibition rate on Bacillus aestuarii and Saccharomycus cerevisiae were 97.1%, 30.9%, respectively, while the colony inhibition rate on Aspergillus niger was 18.4%.