Preparation of SP/Lysozyme Composite Gel and the Inhibition of Staphylococcus aureus

Soy glycinin (SG) and sugar beet pectin (SBP) were cross-linked using laccase to form a complex SG/SBP (SP) and then combined with lysozyme under the heating condition to form SP/lysozyme composite gels. The properties of SP/lysozyme composite gel and its inhibition on Staphylococcus aureus were investigated. Results revealed that the zeta potential changed from -32 to 8.2 mV upon adding lysozyme, its morphology was larger, and the particle size and turbidity increased. The Fourier transform infrared spectroscopy and X-ray diffraction results indicated that the interactions between SP and lysozyme were electrostatic interaction and hydrogen bonding. The mechanical properties showed that the SP/lysozyme composite gel could recover its original shape after 90% strain compression when SP/lysozyme was 10:4 and 10:5, and the storage modulus (G ') was higher at 10:5 about 105 Pa. Scanning electron microscopy results showed that the granular size increased, and the antibacterial property on S. aureus was enhanced.

Automated summary

In this study, soy glycinin and sugar beet pectin were cross-linked using laccase to form a complex, which was then combined with lysozyme to form composite gels. The addition of lysozyme resulted in changes in the properties of the gel, including morphology, particle size, and turbidity. The interactions between the complex and lysozyme were primarily electrostatic and hydrogen bonding. The composite gels exhibited good mechanical properties and enhanced antibacterial activity against Staphylococcus aureus.