Plantaricin IIA-1A5 from Lactobacillus plantarum IIA-1A5 displays bactericidal activity against Staphylococcus aureus

Abstract

Plantaricin IIA-1A5 is a bacteriocin produced by Lactobacillus plantarum IIA-1A5 isolated from Indonesian beef. This research aimed to identify the genes involved in plantaricin IIA-1A5 production and examine its mode of action against Staphylococcus aureus. It has been reported that a bacteriocin structural gene, plnW, is present in genome of L. plantarum IIA-1A5. Here, we reported the presence of additional genes responsible for plantaricin precursor (plnA and plnEF) and a gene encoding the quorum sensor of histidine kinase (plnB). It indicates that genes involved in production of plantaricin IIA-1A5 are organized in at least two bacteriocin operons (plnABCD, plnEFI) and a structural plnW gene. Purified plantaricin IIA-1A5 yielded a single band in SDS-PAGE with apparent size of 6.4 kDa. Amino acid composition of purified plantaricin IIA-1A5 was mainly composed of cationic glutamic acid and cysteine that allowed the formation of disulphide bonds, suggesting plantaricin IIA-1A5 belongs to the pediocin-subclass of class II bacteriocins. Plantaricin IIA-1A5 displayed remarkable antibacterial activity against S. aureus, which was initiated by the adsorption of plantaricin IIA-1A5 onto the cell membrane of S. aureus. The adsorption is hypothesised to be facilitated by non-ionic interactions as it is reduced by the presence of organic solvents or detergents. This adsorption promoted leakage of cellular metabolites through the cell membrane of S. aureus, as indicated by the release of genetic and proteinaceous material of S. aureus observed at 260 and 280 nm, respectively. The leakage also promoted the release of divalent (Ca(2+), Mg(2+)) and monovalent (K(+)) cations. The release of these intracellular components might be due to pores formed in the cell membrane of S. aureus by plantaricin IIA-1A5 as shown by scanning electron microscopy. Altogether, the mode of action of plantaricin IIA-1A5 against S. aureus seems to be bactericidal as indicated by lysis of the cell membrane.

Effectiveness of the Red Dragon Fruit (Hylocereus polyrhizus) Peel Extract as the Colorant, Antioxidant, and Antimicrobial on Beef Sausage

“…High inhibition of Gram-negative bacteria, P. aeruginosa ATCC 27853, by red dragon fruit peel extract resulted from antibacterial compounds content such as phenolic compounds. This assumption was supported by Arief et al (2015) which stated that the Gram-positive bacteria were more susceptible to antibacterial activity due to the absence of a lipoprotein wall that capable of preventing antimicrobial compounds.…”

Prevention of Staphylococcus aureus Contamination on Animal Products Using Indonesian Natural Products

“…The Gram-positive bacteria are more susceptible to antibacterial activity due to the absence of a lipoprotein wall that is capable of preventing antimicrobial compounds. Red dragon fruit peel extract due to its antibacterial compounds such as phenolic compounds could inhibit the growth of bacteria [13]. Application of red dragon fruit extract on beef sausages showed that S. aureus was not detected during 20 days of cold storage.…”

“…Plantaricin IIA-1A5 showed good characteristics as an antimicrobial [14]. Plantaricin IIA-1A5 employs bactericidal activity since it disrupts the cell membrane and promotes the release of ions, proteinaceous, and genetic materials [13]. The cell wall of Gram positive has a thicker peptidoglycan layer, which is dominantly composed of lipoteichoic acid (LTA).…”

“…The genes responsible for bacteriocin production in L. plantarum IIA-1A5 are at least organized in two different operons: plnABCD and plnEFI [13]. The genes have been sequenced.…”

“…to inhibit the growth of S. aureus [13], making it a promising preservative substance to replace the use of chemical preservatives. Plantaricin could be digested by trypsin enzyme.…”