Antioxidant activity of Lactobacillus plantarum strains isolated from traditional Chinese fermented foods

Eleven Lactobacillus plantarum strains isolated from traditional Chinese fermented foods were investigated for their in vitro scavenging activity against hydroxyl and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals, and their resistance to hydrogen peroxide. L. plantarum C88 at a dose of 10(10) CFU/ml showed the highest hydroxyl radical and DPPH scavenging activities, with inhibition rates of 44.31% and 53.05%, respectively. Resistance of intact cells to hydrogen peroxide was also found in all strains. L. plantarum C88 was the most resistant strain against hydrogen peroxide. When L. plantarum C88 was administered to senescent mice suffering oxidative stress induced by d-galactose, the serum superoxide dismutase activity, the glutathione peroxidase activity and the total antioxidant capacity in liver increased significantly, while the level of malondialdehyde in liver decreased significantly. L. plantarum C88 isolated from traditional Chinese fermented dairy tofu could be considered as a potential antioxidant to be applied in functional foods.     

Characterization and probiotic potential of Lactobacillus plantarum strains isolated from cheeses

Ninety-eight Lactobacillus plantarum strains isolated from Italian and Argentinean cheeses were evaluated for probiotic potential. After a preliminary subtractive screening based on the presence of msa and bsh genes, 27 strains were characterized. In general, the selected strains showed high resistance to lysozyme, good adaptation to simulated gastric juice, and a moderate to low bile tolerance. The capacity to agglutinate yeast cells in a mannose-specific manner, as well as the cell surface hydrophobicity was found to be variable among strains. Very high β-galactosidase activity was shown by a considerable number of the tested strains, whereas variable prebiotic utilization ability was observed. Only tetracycline resistance was observed in two highly resistant strains which harbored the tetM gene, whereas none of the strains showed β-glucuronidase activity or was capable of inhibiting pathogens. Three strains (Lp790, Lp813, and Lp998) were tested by in vivo trials. A considerable heterogeneity was found among a number of L. plantarum strains screened in this study, leading to the design of multiple cultures to cooperatively link strains showing the widest range of useful traits. Among the selected strains, Lp790, Lp813, and Lp998 showed the best probiotic potential and would be promising candidates for inclusion as starter cultures for the manufacture of probiotic fermented foods.     

Bacteriocinogenic Lactobacillus plantarum ST16Pa isolated from papaya (Carica papaya) — From isolation to application: Characterization of a bacteriocin

Strain ST16PA, isolated from papaya was identified as Lactobacillus plantarum based on biochemical tests, PCR with species-specific primers and 16S rDNA sequencing. L. plantarum ST16PA produces a 6.5 kDa bacteriocin, active against different species from genera Enterobacter, Enterococcus, Lactobacillus, Pseudomonas, Streptococcus and Staphylococcus and different serotypes of Listeria spp. The peptide is inactivated by proteolytic enzymes, but not when treated with ??-amylase, catalase, lipase, Triton X-100, SDS, Tween 20, Tween 80, urea, NaCl and EDTA. However, presence of 1% Triton X-114 deactivates the bacteriocin. No change in activity was recorded after 2 h at pH values between 2.0 and 12.0, and after treatment at 100 °C for 120 min or 121 °C for 20 min. The mode of activity against Lactobacillus sakei ATCC 15521, Enterococcus faecalis ATCC 19443 and Listeria innocua 2030C was bactericidal, resulting in cell lysis and enzyme-leakage. No significant differences in cell growth and bacteriocin production were observed when strain ST16Pa was cultured in MRS broth at 26 °C and 30 °C for 24 h (25 600 AU/ml). However, even though strain ST16PA grows well in MRS broth at 15 °C and 37 °C, a reduction of bacteriocin production was observed (400 AU/ml and 1600 AU/ml, respectively). In addition, effect of MRS medium components, different initial pH and additions of glycerol or vitamins to the media on bacteriocin ST16Pa production was studied.Peptide ST16PA adsorbs (400 AU/ml) to producer cells. However, bacteriocin ST16Pa was adsorbed at 50% to cells of L. innocua 2030C and at 75% to L. sakei ATCC 15521 and E. faecalis ATCC 19433 when experiments were conducted at 30 °C and pH 6.5. Adsorption of bacteriocin ST16Pa to target cells at different temperatures, pH and in presence of potassium sorbate, sodium nitrate, sodium chloride, ascorbic acid, Tween 80 and Tween 20 were also studied. To the best of our knowledge, this is the first report on detection of L. plantarum in papaya.     

Binding of mutagens to exopolysaccharide produced by Lactobacillus plantarum mutant strain 301102S

Exopolysaccharide (EPS) was produced by Lactobacillus plantarum 301102 on exposure to the mutagenic action of acridine orange and novobiocin. The biological characteristics of this mutant strain 301102S were the same as those of the parent strain, but fermented milk prepared with the mutant strain showed antimutagenic activity on 3-amino-1,4-dimethyl-5H-pyrido indole. Only EPS-bound cells of strain 301102S showed binding ability to mutagens such as heterocyclic amines, and the mutagens were inactivated by binding to EPS. The binding ability was affected by pH; the greatest percentage binding was noted at pH 8.0. Addition of Mg²⁺ and sodium dodecyl sulfate, but not oxgall, inhibited the binding ability. Therefore, the binding mechanism of the EPS may consist of ion-exchange and hydrophobic bonds, and the EPS would bind mutagens in the intestine.     

Diversity of stress tolerance in Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus paraplantarum: A multivariate screening study

Sixty-three strains of the taxonomically related species Lactobacillus plantarum subsp. plantarum, L. plantarum subsp. argentoratensis, L. paraplantarum and L. pentosus isolated from sourdoughs and other food and non-food sources and 14 strains of other members of the genus Lactobacillus were screened for their tolerance of acid, alkaline, heat, oxidative, osmotic, detergent and starvation stresses in order to evaluate the diversity of stress response. Most strains of the L. plantarum group were highly tolerant of acid, alkaline and osmotic stress and highly sensitive to detergent stress, while a larger diversity was found for other stress. Multivariate analysis allowed grouping the strains in clusters with similar response patterns. Stress response patterns in the L. plantarum group were similar to those of species of the L. casei/L. paracasei group but clearly different from those of other mesophilic Lactobacillus. No relationship was found between grouping obtained on the basis of stress response patterns and by genotypic fingerprinting (rep-PCR), nor with the taxonomic position or isolation source of the strains. Further experiments with selected strains showed that exponential phase cells were generally but not always more sensitive than stationary phase cells. The ability to grow under stressful conditions showed a slightly better correlation with the ecological conditions prevailing in the isolation niches of the strains.This study will be the basis for further investigations to identify and exploit the basis of diversity in the stress response of lactic acid bacteria.     

Characterization of Lactobacillus isolates from fermented olives and their bacteriocin gene profiles

Near one hundred isolates of Lactobacillus paraplantarum, Lactobacillus pentosus and Lactobacillus plantarum from table olives were studied. Strains were genotyped by rep-PCR. Although the technique failed to differentiate some isolates at the species level, it proved a robust and easy procedure that could be useful for distinguishing between related strains of L. paraplantarum, L. pentosus and L. plantarum from a large pool of unrelated strains of these species. A PCR-based screening revealed the presence of the plantaricin encoding genes plnA, plnB, plnC, plnD, plnE/F, plnF, plnI, plnJ, plnK, plnG and plnN in most isolates of the three species. Sequences of bacteriocin genes present in L. paraplantarum and L. pentosus were homologous to L. plantarum genes. Through a discriminating analysis of the bacteriocin gene profiles, it was possible to establish a relationship between the origin of isolation and the LAB isolates, regardless of species.     

The effect of Lactobacillus buchneri and Lactobacillus plantarum on the fermentation, aerobic stability, and ruminal degradability of low dry matter corn and sorghum silages

The effect of Lactobacillus buchneri, alone or in combination with Lactobacillus plantarum, on the fermentation, aerobic stability, and ruminal degradability of low dry matter corn and sorghum silages was studied under laboratory conditions. The inoculants were applied at 1 x 10(6) cfu/g. Silages with no additives served as control. After treatment, the chopped forages were ensiled in 1.5-L anaerobic jars. Three jars per treatment were sampled on d 2, 4, 8, 15, and 90. After 90 d of storage, the silages were subjected to an aerobic stability test lasting 5 d, in which CO2 production, as well as chemical and microbiological parameters, was measured to determine the extent of aerobic deterioration. At the end of the ensiling period (d 90), the L. buchneri- and L. buchneri + L. plantarum-inoculated silages had significantly higher levels of acetic acid than the control and L. plantarum-inoculated silages. Therefore, yeast activity was impaired in the L. buchneri- and L. buchneri + L. plantarum-inoculated silages. As a result, L. buchneri, alone or in combination with L. plantarum, improved aerobic stability of the low dry matter corn and sorghum silages. The combination of L. buchneri and L. plantarum reduced ammonia N concentrations and fermentation losses in the silages compared with L. buchneri alone. However, L. buchneri, L. plantarum, and a combination of L. buchneri + L. plantarum did not effect in situ rumen dry matter, organic matters, or neutral detergent fiber degradability of the silages. The L. buchneri was very effective in protecting the low dry matter corn and sorghum silages exposed to air under laboratory conditions. The use of L. buchneri, alone or in combination with L. plantarum, as a silage inoculant can improve the aerobic stability of low dry matter corn and sorghum silages by inhibition of yeast activity.     

Production of salami from beef, horse, mutton, Blesbok (Damaliscus dorcas phillipsi) and Springbok (Antidorcas marsupialis) with bacteriocinogenic strains of Lactobacillus plantarum and Lactobacillus curvatus

Lactobacillus plantarum 423, producer of bacteriocin 423, Lactobacillus curvatus DF38, producer of curvacin DF38, and a bacteriocin-negative mutant of L. plantarum 423 (423m) were evaluated as starter cultures in the production of salami from beef, horse, mutton, Blesbok (Damaliscus dorcas phillipsi) and Springbok (Antidorcas marsupialis). Growth of L. plantarum 423 and L. curvatus DF38 was best supported in Blesbok salami, as revealed by the highest growth rate during sweating, cold smoking and maturation, and final cell numbers after 70 days (1 × 10⁸ and 5 × 10⁷ cfu/g, respectively). Growth of Listeria innocua was the best suppressed in Blesbok salami fermented with L. plantarum 423 and L. curvatus DF38. Growth of L. innocua in horse salami was best suppressed when fermented with L. curvatus DF38. The final pH of salami fermented with L. plantarum 423 and L. plantarum 423m was slightly lower (4.4) compared to the pH of salami produced with L. curvatus DF38 (pH 4.7). No significant differences (P > 0.05) were recorded by a trained sensory taste panel amongst the three starter cultures regarding colour and venison like aroma. Horse, Blesbok and Springbok salami were rated significantly higher (P ? 0.05) in salami flavour than mutton salami, which was rated the lowest for this attribute. Blesbok salami was rated the highest for sour meat aroma, while beef salami was rated the lowest. Springbok salami was rated the highest in terms of oily mouth feel. Beef salami had the most compact structure and horse salami the softest structure of all meat types fermented. In general, salami produced with L. plantarum 423 yielded the best sour meat aroma, colour, texture, venison like flavour, sour meat flavour and oily mouthfeel and is considered superior to the L. plantarum mutant (strain 423m) and L. curvatus DF38.     

Technological and safety properties of Lactobacillus plantarum strains isolated from a Tunisian traditional salted meat

A total of 17 strains of Lactobacillus plantarum, isolated from a Tunisian traditional salted meat and identified by biochemical and molecular methods, were characterized according to their technological properties including acidifying, antimicrobial and enzymatic activities as well as antibiotic resistance in order to select the most suitable for use as starter cultures for the production of fermented sausages. All the strains studied showed good acidifying activity and were able to reduce the pH to less than 4.3 in 72, 48 and 24h at 15, 25 and 37°C respectively. The majority of strains displayed antimicrobial activities against Salmonella arizonae, Staphylococcus aureus, Pseudomonas aeuroginosa and Escherichia coli, however characterization of the antimicrobial substances showed that none of the strains could produce bacteriocins. All the L. plantarum strains were able to hydrolyze casein, whereas none of them was found to possess lipolytic activity. The majority of strains of L. plantarum were resistant to tetracycline, erythromycin, rifampicin, ampicillin and penicillin G.     

Coculture with specific bacteria enhances survival of Lactobacillus plantarum NC8, an autoinducer-regulated bacteriocin producer,in olive fermentations

Bacteriocin production in Lactobacillus plantarum NC8 is activated by coculture with specific bacteriocin production-inducing bacterial strains. The system is further regulated by a three-component regulatory system involving a specific autoinducer peptide (PLNC8IF). We have used L. plantarum NC8 as a starter culture in Spanish-style green olive fermentations and examined the influence of coculturing in its survival. We found that L. plantarum NC8 greatly enhanced its growth and survival in the olive fermentations when coinoculated with two specific bacteriocin-production inducing strains, i.e. Enterococcus faecium 6T1a-20 and Pediococcus pentosaceus FBB63, when compared to singly-inoculated fermentations. In addition, a constitutive bacteriocin-producer NC8-derivative strain was used as a control in the olive fermentations and showed also better viability than the parental NC8 strain. Our results suggest the involvement of bacteriocin production in the viability enhancement found in both cases. We postulate that the presence of specific bacteria is recognized by L. plantarum NC8 as an environmental stimulus to switch a specific adaptive response on, most probably involving bacteriocin production. The design of novel bacteriocin-producing starter cultures for food fermentations should consider their constitutive versus regulated character.     

植物乳杆菌B_(28)产细菌素的发酵条件研究

从来自保加利亚传统燕麦饮料中分离得到的植物乳杆菌B28出发,以腊样芽胞杆菌Baeillus cereus为指示菌,研究了植物乳杆菌B28生长特性以及产生细菌素的最佳时期;不同氮源、碳源和磷酸盐对细菌素抑菌活性性影响以及不同浓度硫酸铵溶液对细菌素的盐析效果。结果表明,植物乳杆菌B28在37℃条件下培养,14~16 h,生长进入稳定期;产生细菌素最佳发酵时间为24 h;70%的硫酸酸铵是适植物乳杆菌细菌素的盐析质量分数为。与对照培养基对比,植物乳杆菌B28的生长情况是酵母提取物>大豆蛋白>胰蛋白胨、蛋白胨、肉膏;乳糖>D-果糖、蔗糖、D-麦芽糖>D-木糖;磷酸盐对植物乳杆菌B28的生长影响不大。并得到了产生细菌素的最佳培养基配方。     

Induction of bacteriocin production by coculture is widespread among plantaricin-producing Lactobacillus plantarum strains with different regulatory operons

We describe the bacteriocin-production phenotype in a group of eight singular bacteriocinogenic Lactobacillus plantarum strains with three distinct genotypes regarding the plantaricin locus. Genotyping of these strains revealed the existence of two different plantaricin-production regulatory operons, plNC8-plNC8HK-plnD or plnABCD, involving three-component systems controlled each of them by a specific autoinducer peptide (AIP), i.e. PLNC8IF or PlnA. While all of the strains produced antimicrobial activity when growing on solid medium, most of them halted this production when cultured in broth, thus reflecting the functionality of regulatory mechanisms. Antimicrobial activity in broth cultures was re-established or enhanced when the specific AIP was added to the culture or by coculturing with specific bacterial strains. The latter trait appeared to be widespread in bacteriocinogenic L. plantarum strains independently of the regulatory system used to regulate bacteriocin production or the specific bacteriocins produced. The induction spectrum through coculture, i.e. the pattern of bacterial strains able to induce bacteriocin production, was characteristic of each individual L. plantarum strain. Also, the ability of some bacteria to induce bacteriocin production in L. plantarum by coculture appeared to be strain specific. The fact that induction of bacteriocin production by coculturing appeared to be a common feature in L. plantarum can be exploited accordingly to enhance the viability of this species in food and feed fermentations, as well as to contribute to probiotic functionality when colonising the gastrointestinal tract.     

植物乳杆菌(Lactobacillus plantarum)CW5的筛选及细菌素抑菌活性的研究

为了提高抑菌活性,对植物乳杆菌(Lactobacillus plantarum)CW5产细菌素的发酵条件进行了优化,分别研究了培养时间、温度、接种量、培养基起始pH、培养基碳源、氮源等因素对细菌素产生的影响,通过单因素水平实验和正交实验,确定产细菌素的最佳培养基组合和最佳发酵条件为:葡萄糖3%,胰蛋白胨1.5%,蛋白胨1.5%,酵母膏1%,硫酸镁0.058%,吐温80 0.2%,30℃培养24 h,培养基起始pH为6.5,接种量2%。CW5在优化前效价为367.82 IU/mL,优化后效价为1619.85 IU/mL,提高了340.39%。     

Survival of Lactobacillus plantarum in model solutions and fruit juices

The aim of the work was to study the survival of Lactobacillus plantarum NCIMB 8826 in model solutions and develop a mathematical model describing its dependence on pH, citric acid and ascorbic acid. A Central Composite Design (CCD) was developed studying each of the three factors at five levels within the following ranges, i.e., pH (3.0-4.2), citric acid (6-40 g/L), and ascorbic acid (100-1000 mg/L). In total, 17 experimental runs were carried out. The initial cell concentration in the model solutions was approximately 1 × 10⁸ CFU/mL; the solutions were stored at 4 °C for 6 weeks. Analysis of variance (ANOVA) of the stepwise regression demonstrated that a second order polynomial model fits well the data. The results demonstrated that high pH and citric acid concentration enhanced cell survival; one the other hand, ascorbic acid did not have an effect. Cell survival during storage was also investigated in various types of juices, including orange, grapefruit, blackcurrant, pineapple, pomegranate, cranberry and lemon juice. The model predicted well the cell survival in orange, blackcurrant and pineapple, however it failed to predict cell survival in grapefruit and pomegranate, indicating the influence of additional factors, besides pH and citric acid, on cell survival. Very good cell survival (less than 0.4 log decrease) was observed after 6 weeks of storage in orange, blackcurrant and pineapple juice, all of which had a pH of about 3.8. Cell survival in cranberry and pomegranate decreased very quickly, whereas in the case of lemon juice, the cell concentration decreased approximately 1.1 logs after 6 weeks of storage, albeit the fact that lemon juice had the lowest pH (pH ~ 2.5) among all the juices tested. Taking into account the results from the compositional analysis of the juices and the model, it was deduced that in certain juices, other compounds seemed to protect the cells during storage; these were likely to be proteins and dietary fibre In contrast, in certain juices, such as pomegranate, cell survival was much lower than expected; this could be due to the presence of antimicrobial compounds, such as phenolic compounds.     

Enhancing the antilisterial effect of Lactobacillus curvatus CWBI-B28 in pork meat and cocultures by limiting bacteriocin degradation

This work focused on Listeria monocytogenes growth inhibition and growth rebound in raw and cooked pork meat inoculated with Lactobacillus curvatus strains. During storage of raw meat homogenates in the presence of the bacteriocin-producing strain Lactobacillus curvatus CWBI-B28wt, the Listeria monocytogenes cfu count was initially reduced to an undetectable level, but a growth rebound occurred after two weeks, coinciding with loss of 70% of the bacteriocin activity present at the end of week 2. The Listeria growth rebound was suppressed when proteolysis of bacteriocin was countered by the absence of proteases (bacteriocin addition to cooked meat) or the presence of 1% soy flour (added to provide competing substrates). Further experiments confirmed that bacteriocin is sensitive to the action of proteolytic enzymes isolated from both Lactobacillus curvatus CWBI-B28wt and the meat matrix. Bacteriocin proteolysis thus emerges as a cause of Listeria growth rebound.     

Biochemical,antimicrobial and molecular characterization of a noncytotoxic bacteriocin produced by Lactobacillus plantarum ST71KS

Lactobacillus (Lb.) plantarum ST71KS was isolated from homemade goat feta cheese and identified using biochemical and molecular biology techniques. As shown by Tricine-SDS-PAGE, this lactic acid bacterium produces a bacteriocin (ST71KS) with an estimated molecular weight of 5.0 kDa. Bacteriocin ST71KS was not affected by the presence of α-amylase, catalase and remained stable in a wide range of pH and after treatment with Triton X-100, Triton X-114, Tween 20, Tween 80, NaCl, SDS, urea and EDTA. This bacteriocin also remained active after being heated at 100 °C for 2 h and even after 20 min at 121 °C; however, it was inactivated by proteolitic enzymes. Production of bacteriocin ST71KS reached 6400 AU/mL during stationary growth phase of Lb. plantarum cultivated in MRS at 30 °C and 37 °C. Bacteriocin ST71KS displayed a bactericidal effect against Listeria monocytogenes strains 603 and 607 and did not adsorb to the producer cells. Lb. plantarum ST71KS harbors two bacteriocin genes with homology to plantaricin S and pediocin PA-1. These characteristics indicate that bacteriocin ST71KS is a class IIa bacteriocin. The peptide presented no toxic effect when tested in vitro with kidney Vero cells, indicating safe technological application to control L. monocytogenes in foods.     

Optimisation of bacteriocin production of Lactococcus lactis subsp. lactis MA23, a strain isolated from Boza

Lactococcus lactis subsp. lactis MA23 produces a bacteriocin (6400 AU/mL) that inhibits the growth of many Gram‐positive bacteria but is not active against Gram‐negative bacteria. This bacteriocin inhibits growth of lactococcal strains that are producing nisin, lacticin or lactococcin suggesting it to be different from these bacteriocins. The nutritional requirements and optimal growth conditions for MA23 bacteriocin production were studied with fed‐batch fermentations. The optimal pH, carbon source and nitrogen source for bacteriocin production were pH 6.5, sucrose (0.5%) and yeast extract (1%), respectively.     

Mixed species biofilms of Listeria monocytogenes and Lactobacillus plantarum show enhanced resistance to benzalkonium chloride and peracetic acid

We investigated the formation of single and mixed species biofilms of Listeria monocytogenes strains EGD-e and LR-991, with Lactobacillus plantarum WCFS1 as secondary species, and their resistance to the disinfectants benzalkonium chloride and peracetic acid. Modulation of growth, biofilm formation, and biofilm composition was achieved by addition of manganese sulfate and/or glucose to the BHI medium. Composition analyses of the mixed species biofilms using plate counts and fluorescence microscopy with dual fluorophores showed that mixed species biofilms were formed in BHI (total count, 8-9 log₁₀ cfu/well) and that they contained 1-2 log₁₀ cfu/well more L. monocytogenes than L. plantarum cells. Addition of manganese sulfate resulted in equal numbers of both species (total count, 8 log₁₀ cfu/well) in the mixed species biofilm, while manganese sulfate in combination with glucose, resulted in 1-2 log₁₀ more L. plantarum than L. monocytogenes cells (total count, 9 log₁₀ cfu/well). Corresponding single species biofilms of L. monocytogenes and L. plantarum contained up to 9 log₁₀ cfu/well. Subsequent disinfection treatments showed mixed species biofilms to be more resistant to treatments with the selected disinfectants. In BHI with additional manganese sulfate, both L. monocytogenes strains and L. plantarum grown in the mixed species biofilm showed less than 2 log₁₀ cfu/well inactivation after exposure for 15 min to 100 μg/ml benzalkonium chloride, while single species biofilms of both L. monocytogenes strains showed 4.5 log₁₀ cfu/well inactivation and single species biofilms of L. plantarum showed 3.3 log₁₀ cfu/well inactivation. Our results indicate that L. monocytogenes and L. plantarum mixed species biofilms can be more resistant to disinfection treatments than single species biofilms.     

泡菜中植物乳杆菌的筛选及益生活性研究

从民间自制泡菜中筛选乳酸菌。根据菌落形态,革兰氏染色和溶钙透明圈,分离得到17株乳酸菌菌株,用16S r DNA测序鉴定分离菌株,并测试了其耐酸和耐胆盐能力。结果表明,筛选菌株中WHLP-01、WHLP-02、WHLP-03和WHPE-02四株菌株可以在p H=2.0的环境下生存2 h;WHLP-01与WHLP-02两株菌株可以在0.3%胆盐浓度下存活;其中菌株WHLP-01属植物乳杆菌,其对常见的8株致病菌均有明显的抑制效果和降胆固醇能力,可以作为微生态制剂的候选菌株深入研究。      

Expression of Lactobacillus pentosus B96 bacteriocin genes under saline stress

This research studied the influence of sodium chloride on bacteriocin activity of table olives’ strain Lactobacillus pentosus B96. The strain was cultured in MRS under different NaCl concentrations (0, 4, 6 and 8%, in w/v). In MRS, maximum bacteriocin activity was achieved 9 h later. A medium containing 4 or 6% NaCl (w/v) increased the total bioactivity of the strain and an 8% NaCl reduced it. Real-time PCR was used to monitor the genetic expression of the bacteriocin genes plnA, plnB, plnC, plnE/F, plnJ, plnK, plnN and plantaricin S. Cultured in MRS, plantaricin S reached its maximum expression during the lag phase while plnE/F expresses during the exponential phase. The presence of sodium chloride in the medium moved the maximum expression of plantaricin S to the stationary phase, independently of the concentration. 4% (w/v) of NaCl didn’t affect the expression pattern of plnE/F while promotes the expression of plnN during both the lag and the exponential phases. More sodium chloride, 6% (w/v) maintained the expression of plnN in the pag phase but not in the exponential and moved plnE/F expression to the stationary phase. Plantaricin S, plnE/F and plnN over-expressed during the stationary phase in the higher sodium chloride concentration assayed, 8% (w/v). The relative expression level of plsA was 1000-fold higher than that of the plnE/F and plnN genes and even the ldhD constitutive gene used. Under our conditions, expression of plnA, plnB, plnC, plnJ and plnK genes was not observed.