Studies on antibacterial activities of Cordyceps militaries

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%.