Purification and Partial Characterization of Bacteriocin Lac-B23, a Novel Bacteriocin Production by Lactobacillus plantarum J23, Isolated From Chinese Traditional Fermented Milk

Abstract

The exploration and evaluation of bacteriocin-producing lactic acid bacteria (LAB) have been one of the powerful means to food preservation. A total of 300 strains were isolated from Chinese traditional fermented milk products. A bacteriocin-producing LAB, named Lactobacillus plantarum J23, was screened and identified. Bacteriocin Lac-B23 from L. plantarum J23 was purified by 80% ammonium sulfate precipitation, cation-exchange chromatography, and reverse-phase high-performance liquid chromatography. Molecular weight of bacteriocin Lac-B23 was determined to be approximately 6.73 kDa by tricine sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, and it was confirmed as a novel bacteriocin by liquid chromatography-mass spectrometry. Moreover, bacteriocin Lac-B23 showed thermal stability when heated at below 100°C for 30 min, pH stability between pH 2.0 and 12.0, and sensitivity to trypsin, proteinase K, and proteinase E. The antimicrobial activity of bacteriocin could be enhanced by addition of Fe2+, Mn2+, and ethyl alcohol, and inhibited by Cu2+, K+, Ca2+, Zn2+, Mg2+, and sodium chloride. The results suggested bacteriocin Lac-B23 to have potential application prospects in the food industry.

A new class of antimicrobial molecules derived from kefir, effective against Pseudomonas aeruginosa and methicillin resistant Staphylococcus aureus (MRSA) strains

“…In contrast, the molecular fraction of kefir serum with mass between 1 and 10 kDa demonstrated only bacteriostatic effect. This result is in accord with studies that demonstrated that the majority of bacteriocins produced by bacterial strains isolated from kefir and traditional fermented milk, have mass between 1 and 10 kDa 7,16,33,34 .…”

Partial purification and characterization of a broad‐spectrum bacteriocin produced by a Lactobacillus plantarum zrx03 isolated from infant's feces

“…To evaluate thermal stability, 5 ml aliquots of bacteriocin were subjected to different heat treatments for 80, 90, 100, and 121°C, respectively, for 30 min with treated at room temperature as a control (Zhang et al, 2018). The effect of pH on the antimicrobial activity of the bacteriocin was tested by dissolving the bacteriocin sample of 5 ml of 1 M NaOH or 1 M HCl-adjusted PBS solution at a pH range of 2.0-9.0 (in increments of one pH unit), untreated by acid or alkali as controls (Goyal et al, 2018).…”

“…Goyal et al (2018) obtained the bacteriocin-producing L. lactis 63 from Indian dairy products, which was found to have a broad antimicrobial spectrum. Zhang et al (2018) isolated Lactobacillus plantarum J23 from Chinese traditional fermented milk, the fermentation supernatant of which had a zone of inhibition diameter of more than 5 mm for Listeria monocytogenes. This experiment aims to isolate and identify a lactic acid bacteria with excellent antibacterial activity from the feces of infant and explore the crude extraction method and basic characteristics of a purified bacteriocin produced by L. plantarum zrx03 isolated from infant's feces to facilitate the research and development of L. plantarum bacteriocin-related products.…”

Insights Into The Broad Antibacterial Spectrum Of Bacteriocin Isolated From Probiotic Lactobacillus Fermentum LMEM22 Strain

“…The bacteriocin of L. fermentum sl36 strain isolated from goat milk, which inhibited the growth of food-borne bacteria (Enterococcus faecalis, Listeria monocytogenes, Listeria innocua, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli),, lost the antibacterial activity, against gram-positive strains, after treatment with trypsin (Mitjans et al,, 2018). The antimicrobial bacteriocin Lac-B23, of ≈6.73 kDa from L. plantarum J23 strain, demonstrated complete loss of anti-Listeria monocytogenes activity on being treated with proteinase K, trypsin, and proteinase E, indicating the complete disruption of bacteriocin Lac-B23, by proteolytic enzymes, due to its proteinaceous nature (Zhang et al,, 2018).As has been reported by Todorov et al (2013), the Lactobacillus sakei strains ST22Ch, ST153Ch and ST154Ch (from fermented meat products), containing bacteriocin of 3 kDa, 10 kDa and 3 kDa, respectively (in tricine/SDS-PAGE), which inhibited the growth of gram-positive (Enterococcus spp., Staphylococcus spp., Listeria spp. and Streptococcus spp.)…”