A novel bacteriocin from Lactobacillus salivarius against Staphylococcus aureus: Isolation, purification, identification, antibacterial and antibiofilm activity

Abstract

Bacteriocins are known to inhibit various foodborne bacteria and their biofilms; however, few bacteriocins with activity against food-derived Staphylococcus aureus have been reported. Here, a novel bacteriocin (XJS01) from the Lactobacillus salivarius strain CGMCC2070 was obtained, purified, and extensively characterized. Molecular mass and amino acid composition of XJS01 were 666.31 Da and F–S-G-L-A-G-D, respectively. XJS01 inhibited the S. aureus strain 2612:1606BL1486 (S. aureus_26), which was originally isolated from chicken meat. Also, XJS01 showed good resistance to heat treatment, and was only susceptible to pepsin treatment. The minimum inhibitory concentration of XJS01 against S. aureus_26 was 9.85 μg/mL, which is lower than previously reported levels for most described bacteriocins. Furthermore, exposure to XJS01 also decreased viability and significantly inhibited (p < 0.05) planktonic S. aureus_26 cells. Biofilm formation of S. aureus_26 was also significantly inhibited (p < 0.05). The results of electron microscopy showed that XJS01 impaired membrane permeability in S. aureus_26, caused leakage of cytoplasmic content, and led to cell deformation. In summary, this study identifies the bacteriocin XJS01 as a potentially candidate for the control of S. aureus in foods in either planktonic or biofilm states.