摘要

In this study, the antibacterial activity of protease hydrolysates from Silybum marianum protein isolates (SMPIs) was investigated. Neutral protease, papain, pepsin and alkaline protease were used as experimental enzymes, while Escherichia coli, Staphylococcus aureus, Sarcina lutea and Bacillus subtilis were the bacterial indicators. The results showed that neutral protease, papain and pepsin hydrolysates exerted inhibitory effects on the four types of bacteria tested. However, alkaline protease hydrolysates of SMPI showed stimulatory effects on replication of the four bacteria tested. The antibacterial mechanism of SMPI hydrolysates was studied using scanning electron microscopy, and the results showed effective inhibition of E. coli (Gram-negative, G(-)) and S. aureus (Gram-positive, G(+)). It is speculated that the underlying mechanism of SMPI hydrolysates may involve injury to E. coli and S. aureus cell membranes. Currently, no similar studies have been conducted on the antibacterial activity of SMPI.