Purification, Characterization, and Mode of Action of Pentocin JL-1, a Novel Bacteriocin Isolated from Lactobacillus pentosus, against Drug-Resistant Staphylococcus aureus

Abstract

Staphylococcus aureus and its drug-resistant strains, which threaten public health and food safety, are in need of effective control by biopreservatives. A novel bacteriocin, pentocin JL-1, produced by Lactobacillus pentosus that was isolated from the intestinal tract of Chiloscyllium punctatum, was purified by a four-step chromatographic process. Mass spectrometry based on MALDI-TOF indicated that pentocin JL-1 has a molecular mass of 2987.23 Da. Only six of the twenty-five amino acids could be identified by Edman degradation. This bacteriocin is thermostable and tolerates a pH range of 5–7. Also, it is sensitive to proteinase K, trypsin, pepsin, and alkaline protease. This bacteriocin has a broad inhibitory spectrum against both Gram-positive and Gram-negative strains and in particular is effective against multidrug-resistant S. aureus. Additionally, we showed that the cell membrane is the target of pentocin JL-1 against methicillin-resistant S. aureus (MRSA), causing a loss of proton motive force. Furthermore, pentocin JL-1 has a drastic impact on the structure and integrity of MRSA cells. These results suggest that pentocin JL-1 has potential as a biopreservative in the food industry.

The characterization of bacteriocins produced by Lactobacillus plantarum strains isolated from traditional fermented foods in Indonesia and the detection of its plantaricin-encoding genes

“…After incubation for 2 h at pH values from pH 2.0 to 8.0 stable activity but its activity slightly reduced at pH 10.00 and showed activity at pH 12.0 This result showed that the BLS was resistant to acid conditions (Table 4). That agreement with other research on characterized L. plantarum that inhibition zone pH treatment stable at range pH 2.0 to 8.0 (Jiang et al 2017).…”

Towards understanding the antagonistic activity of phytic acid against common foodborne bacterial pathogens using a general linear model

“…The bacteriostatic or bactericidal mode of action of IP6 was tested using a method described previously by Jiang et al [45]with some modifications. L. monocytogenes ATCC 19117, S. aureus ATCC 6538 and S. Typhimurium ATCC 14028 were cultivated in 100 mL of PALCAM, Chapman broth and xylose lysine xeoxycholate (XLD) broth, respectively.…”

“…Values with a different letter (A-E) of a same diameter inhibition zone are significantly different (P<0.05) To investigate the effects of varying IP6 dose on L. monocytogenes, S. aureus and S. Typhimurium, the bacterial growth was followed over 24 h and evaluated in comparison with the control culture (without addition of IP6), following the protocol developed by Jiang et al [45]. IP6 was added to L. monocytogenes ATCC 19117, S. aureus ATCC 6538 and S. Typhimurium ATCC 14028cells after 3 h of incubation, when growth reached the beginning of the exponential phase (cell density of about 10 6 CFU/ml).…”

Crystal structure and site-directed mutagenesis of circular bacteriocin plantacyclin B21AG reveals cationic and aromatic residues important for antimicrobial activity

“…Glycines are often found in flexible loop regions as they do not contain a side chain, increasing the conformational flexibility (demonstrated by NMR solution structures of other circular bacteriocins) 13,28,43 . The hydrophobic core residues are Ile 1 , Ile 4 , Ala 5 , Val 10 , Leu 12 , Ala 20 , Leu 24 , Leu 30 , Val 33 , Ala 34 , Ile 37 , Leu 38 , Val 40 , Leu 42 , Ala 46 , Ala 50 and Ala 58 . All of these residues have <20% solvent exposure calculated based on GETAREA 44 .…”

“…Replacing aspartic acid at position 17 with the glutamic acid strongly enhanced the antimicrobial activity of the pediocin-like bacteriocin sakacin P. This result suggests that the anionic residues interact in a structurally specific and restricted manner with a cationic region on the target cell or on the peptide itself 49 . Given that bacteriocins generally kill through disruption of proton motive force 50 or through the Grotthuss mechanism of gramicidin 51 , placement of negative charges near the pore may facilitate pore selectivity and cation flow out of the target cell by reducing the electrostatic energy profile and increasing selectivity for divalent cations such as Ca 2+ 52 . These findings suggest that anionic residues are as important as cationic residues in terms of target specificity of the bacteriocins.…”