Antibacterial characteristics of glycinin basic polypeptide against Staphylococcus aureus.

This paper aims to study the antibacterial action of glycinin basic polypeptide (GBP) on Staphylococcus aureus (S. aureus). Herein, the minimum inhibitory concentration (MIC) of GBP against S. aureus was 0.2 mg/mL. Atomic force microscopy (AFM) imaging showed that GBP seriously damaged the morphology of the S. aureus cells. GBP (0.8 mg/mL) enhanced the relative release of β-galactosidase to 25.48% when compared to the control. The activity of the respiratory-chain dehydrogenase of S. aureus decreased with increasing GBP concentration. GBP could cause a leakage of intracellular substances. Additionally, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that S. aureus bacterial proteins decreased in response to the time period of treating the bacterial cells with GBP. These results indicate that GBP could remarkably inhibit S. aureus and is, therefore, a potential food preservative.