A novel bacteriocin produced by Lactobacillus plantarum LpU4 as a valuable candidate for biopreservation in artisanal raw milk cheese

Abstract

Indigenous lactic acid bacteria-producing bacteriocins could enhance the microbiological safety of traditional cheeses. This study aimed to detect bacteriocinogenic strains among 35 Lactobacillus plantarum isolated from artisanal, raw sheep-milk cheeses. The isolates were identified by API 50 CHL and speciesspecific PCR. As displayed by agar well-diffusion assay, the cell-free supernatant of L. plantarum LpU4 showed the highest antimicrobial activity against Enterococcus faecalis JH2-2. The activity was not detected after treatment with proteinase K, pepsine and pronase. An active peptide band was shown by tricine-sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and subsequent bioassay. MALDI-TOF analysis revealed a protein of 4,866.7 Da, having no homology with other known bacteriocins. The novel bacteriocin (named plantaricin LpU4) was heat stable (121°C for 15 min), unaffected by chemicals as Tween 20, SDS, Triton ×100, EDTA, NaCl and exposure to a wide range of pH. The synthetic machinery encoding for the plantaricin was plasmid-located, as deduced by plasmids curing. Activity spectrum included several lactic acid bacteria and Staphylococcus aureus strains having antibiotic resistance phenotype. Plantaricin LpU4 showed a bacteriostatic mode of action and an enhanced activity at acidic pHs. Maximal production (3,200 AU.mL

Antibiofilm potential of Lactobacillus plantarum spp. cell free supernatant (CFS) against multidrug resistant bacterial pathogens

“…Siahmezgi cheese, a traditional cheese which is produced in the north of Iran, and determined its antibiofilm potential against multidrug resistance bacterial pathogens. Occurrence of L. plantarum in cheese microbiota appears to be a common trait of a variety of milk cheeses (4). Isolation of L. plantarum strains from traditional cheese has been reported previously and have been shown to be able to produce a variety of antimicrobial compounds (13).…”

“…These compounds have antibacterial and antibiofilm potentials which are able to inhibit bacterial infectivity. Several studies have reported antibiofilm potential of bacteriocines produced by LAB bacteria (4)(5). Moreover, some studies reported that a number of exopolysacharides isolated from commercial fermented milk were capable of interfering with the adhesion of several enteric pathogens (6)(7).…”

“…Moreover, some studies reported that a number of exopolysacharides isolated from commercial fermented milk were capable of interfering with the adhesion of several enteric pathogens (6)(7). The LAB from traditional cheese may produce bioactive compounds with antibiofilm activity and could be used for prevention of bacterial infections and food spoilage (4). However, the stability of these bioactive compounds under unfavorable conditions needs to be characterized.…”

In vitro characterization of Lactobacillus crispatus IP174178 and its live biotherapeutic product for prevention of vaginal infections

“…Lactobacillus spp. are commonly identified as the biomarker of a healthy vagina which protect the mucosa against the establishment of pathogenic microorganisms [8].This protection is mainly due to the ability to adhere to vaginal cells and the secretion of antimicrobial compounds such as H 2 O 2 , organic acids [9,10], and bacteriocins [11,12]. The vaginal microbiota has been characterized by the dominance of a single species most closely related to the Lactobacillus spp.…”

Efeito da adição de culturas probióticas sobre aspectos microbiológicos e parâmetros fermentativos de Queijo Artesanal das Terras Altas da Mantiqueira

“…Isto se deve principalmente à sua capacidade de produzir compostos que inibem o crescimento de micro-organismos de grande relevância na saúde pública. Esta característica, juntamente com suas possíveis aplicações, são amplamente documentadas e discutidas em diversos estudos presentes na literatura (ŠUŠKOVIĆ et al, 2010;SABO et al, 2014;SIDIRA et al, 2014;BARBOSA et al, 2015;GONZÁLEZ e ZÁRATE, 2015;MILIONI et al, 2015).…”