Screening of fibrinolytic enzymes from lactic acid bacterial isolates associated with traditional fermented soybean foods

Fibrinolytic enzyme producing microorganisms with high fibrin specificity were screened, including lactic acid bacteria from fermented soybean foods of North-East India. A total of 5 isolates, including Lactococcus lactis (FS1), Vagococcus lutrae (FS6), Vagococcus fluvialis (FS7), Weissella thailandensis (FS8), and Bacillus methylotrophicus (FS19) were found to hydrolyze fibrin directly on a plasminogen-free fibrin plate. Hydrolysis of fibrin was stronger with crude enzymes than with plasmin, indicating high fibrin specificity. The molecular weights of these enzymes, as determined by SDS-PAGE, ranged from 35 to 116 kDa.     

Antihypertensive activity of milk fermented by Enterococcus faecalis strains isolated from raw milk

A total of 231 microorganisms were isolated from raw cow milk samples and the angiotensin-converting enzyme-inhibitory (ACEI) activity of the resultant fermented milk produced with the isolated microorganisms was assayed. Forty-six of these microorganisms were selected on the basis of high ACEI activity. Four Enterococcus faecalis strains stood out as producers of fermented milk with potent ACEI activity (IC₅₀ (the protein concentration that inhibits 50% of ACE activity): 34–59 μg mL⁻¹). Single doses (5 mL kg⁻¹) of the whey fraction obtained from these fermented milk samples were administered to spontaneously hypertensive rats (SHR) and to normotensive Wistar-Kyoto (WKY) rats in order to investigate their possible antihypertensive activity. Highly significant decreases in the systolic blood pressure (SBP) and in the diastolic blood pressure (DBP) were observed when the fermented milk was administered to SHR. Nevertheless, the fermented milk did not modify the SBP and the DBP of the WKY rats. Raw cow milk is an excellent source of wild lactic acid bacteria able to produce fermented milk with antihypertensive activity and antihypertensive activity of milk fermented by Enterococcus faecalis strains was associated with peptides different from Ile-Pro-Pro and Val-Pro-Pro.     

Suppressive effect of Tetragenococcus halophilus,isolated from fish-nukazuke,on histamine accumulation in salted and fermented fish

Occasionally, quantities higher than 1000 mg/kg of histamine (Hm) accumulate in salted and fermented fish products by the histidine decarboxylase of halophilic lactococci Tetragenococcus sp. In a total of 200 isolates from fish nukazuke (salted and fermented fish with rice bran), 13 strains produced Hm more than 200 μg/ml in 0.5% histidine containing broth, whereas 130 isolates produced absolutely no Hm. Among the strains, 22 strains suppressed the Hm production of the Hm-forming (HmF) strains. Both the HmF and Hm-suppressing (HmS) strains were identified as Tetragenococcus halophilus. To observe the Hm-suppressing effect, a specified quantity of live cells was needed. In the case of 10% NaCl salted sardine, inoculation with 3 log cells/g of a strain HmF-131 resulted in a significant Hm accumulation, 2800 μg/g in 30 days at 20 °C. The increase in Hm was clearly suppressed by 9 log live cells/g of strain HmS-129. These results suggest that HmS-129 can be used as a starter for salted and fermented fish products, enhancing food safety.     

Assessing Rubus honey value: Pollen and phenolic compounds content and antibacterial capacity

Twenty-three honey samples from Galicia (Northwest Spain) were analysed to determine their botanical origin, phenolic compounds and antibacterial activity. In all samples Rubus pollen was predominant, followed by that of Castanea sativa. Other important pollens found belong to Cytisus type, Trifolium repens, Echium, Eucalyptus globulus, Erica umbellata, Erica cinerea, Campanula type and Frangula alnus.Eight phenolic compounds (caffeic, p-coumaric and ellagic acids, pinocembrin, chrysin, galangin, tectochrysin and kaempferol) were determined by solid-phase extraction (SPE) followed by HPLC/DAD analysis. p-Coumaric and ellagic acids were the main constituents of the phenolic fraction (ca. 5.5 mg/kg each, mean value), followed by the pair chrysin plus galangin (ca. 1.2 mg/kg, mean value) and pinocembrin (ca. 1.0 mg/kg, mean value). Antibacterial activity was checked against five Gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Enterococcus faecalis and Bacillus cereus) and four Gram-negative bacteria (Proteus mirabilis, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium). B. cereus and P. mirabilis were the most sensitive microorganisms. This is the first study concerning the phenolic compounds and antibacterial activity of Rubus honey, which proved to be a good source of phenolic compounds and antimicrobial agents with potential health benefits.     

Preliminary characterization of bacteriocins from Lactococcus lactis,Enterococcus faecium and Enterococcus mundtii strains isolated from turbot (Psetta maxima)

The aim of this work was the characterization of new strains of lactic acid bacteria (LAB) from farmed fish and with potential application as biopreservatives against both Listeria monocytogenes and Staphylococcus aureus. Twenty-five strains of LAB isolated from the muscle of farmed turbot were investigated. Genetic identification of the bacteriocin-producing LAB strains was performed by means of a PCR method using novel BAL1/BAL2 16S ribosomal-RNA-targeted primers. Maximum bacteriocin production by Lactococcus lactis ssp. lactis USC-39, Enterococcus faecium USC-46 and Enterococcus mundtii USC-51 was detected in the stationary phase of growth. Both acidification and the production of hydrogen peroxide by LAB were ruled out as the source of the inhibition. In contrast, the antimicrobial activity of all three LAB strains was inactivated by the addition of proteinase K, thus confirming the proteinaceous nature of the inhibition. The activity against L. monocytogenes was maintained in the 3.5–5.5 or 3.5–6.5 pH range, depending on the LAB strain. Likewise, inhibition of S. aureus strains was observed in the 3.5–4.5 and in the 3.5–5.5 pH ranges, depending on the LAB strain and on the S. aureus strain tested. Bacteriocin activity was stable in all three strains after heating the cell-free extract for 60 min at 100 °C, or even for 15 min at 121 °C, in all the three LAB strains. The acidic and heat-resistant bacteriocins produced by the three LAB strains isolated from turbot, able to inhibit the growth of both L. monocytogenes and S. aureus may find application as biopreservatives in fermented and/or heated food products.     

Comparison of the antioxidant capacity and the antimicrobial activity of black and green tea

Tea is a common beverage. The green tea is preferentially recommended for its strong antioxidant properties and also for its antimicrobial activity. The antioxidant capacities of 30 samples (black and green tea) were determined by the chemiluminescent Trolox equivalent antioxidant capacity (TEAC) determination. The average value of TEAC of the non-fermented (green tea) and semi-fermented tea samples was 1.43 mM and the average value of TEAC of the fermented teas (black tea) samples was 1.43 mM. All samples were stored in freezer (?20 °C) and the TEAC determination was repeated after a year. The average values of TEAC of non-fermented and semi-fermented tea samples were twofold lower in comparison to fermented tea samples and only 20% of average value of TEAC of the fresh tea infusion. The parallel determinations of minimal inhibitory concentration (MIC) on gram-positive and gram-negative bacterial strains (Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli) were done. Also the MIC was possible to determine after a year. The assumed prevailing antioxidant and antimicrobial activities of non-fermented tea infusions were not confirmed as well as the dominant antioxidant and antimicrobial properties of specific type of tea infusion.     

Simultaneous detection and enumeration of viable lactic acid bacteria and bifidobacteria in fermented milk by using propidium monoazide and real-time PCR

This study describes a procedure that allows specific detection and enumeration of viable bacteria in four species of lactic acid bacteria (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus casei subsp. casei and Lactobacillus acidophilus) and of Bifidobacterium lactis, mixed in fermented milk products. The procedure is based on the combined use of propidium monoazide (PMA), able to distinguish between viable and irreversibly damaged cells, with species-specific quantitative real-time PCR (RTi-PCR). Loss of viability of the species in a fermented milk through storage at 4 °C was similarly (P < 0.05) detected by PMA–RTi-PCR and selective plate counts. Furthermore, comparison of results obtained by both methods showed a Pearson linear correlation of 0.995. The enumeration of viable bacteria by PMA–RTi-PCR could be performed in 3 h, whereas enumeration by selective plate counts required three days. The procedure developed is a fast method for the identification, enumeration and discrimination of viability of lactic acid bacteria and bifidobacteria mixed in fermented milk products.     

Apple,grape or orange juice: Which one offers the best substrate for lactobacilli growth? — A screening study on bacteria viability,superoxide dismutase activity,folates production and hedonic characteristics

Fermentation can contribute to improve functional aspects of foods. The first goal of this study was to determine amongst apple, grape and orange juices, the one with the best bacterial growth performance during fermentation by Lactobacillus strains from commercial and artisanal food origins, at 40 °C for 48 h. The juice with the highest bacterial growth was evaluated for bacteria viability during 4 weeks of cold storage, superoxide dismutase (SOD) activity and folates production analyzed through HPLC/fluorimetry. Acceptability of fermented juice was appraised through hedonic analysis. Lactobacilli counts were the highest in apple and the lowest in orange juices at t = 48 h. In most cases, bacteria counts were higher in fermented (5.5 to 9.5 log CFU/ml) than in supplemented apple juices (4.2 to 5.7 log CFU/ml), at the 4th week of cold storage. SOD activity was significantly increased in all apple juices fermented by commercial Lactobacilli strains. Folates were produced in apple juices fermented by Lactobacillus plantarum and Lactobacillus rhamnosus. Apple juice was the best substrate for Lactobacillus growth and, considering bacterial viability and overall acceptance by the panelists, Lactobacillus acidophilus L10 was the most suitable strain for apple juice fermentation.     

Carbohydrate composition of honey from different floral sources and their influence on growth of selected intestinal bacteria: An in vitro comparison

Five human intestinal Bifidobacterium spp. (B. longum, B. adolescentis, B. breve, B. bifidum, and B. infantis) and intestinal microorganism (Bacteriodes thetaiotaomicron, Clostridium perfringens, Eubacterium aerofaciens, and Enterococcus faecalis) were cultured in De Man Rogosa Sharpe (MRS) medium or thioglycollate medium supplemented (5% w/v) with different unifloral honeys (sourwood, alfalfa, or sage). Inoculated samples were incubated anaerobically at 37 °C for 48 h. Samples were collected at 12 h intervals and examined for specific growth rate. Levels of fermentation end products (lactic and acetic acids) produced by Bifidobacterium spp. were measured by high-pressure liquid chromatography. Growth of intestinal microorganisms co-cultured with Bifidobacterium spp. in the presence of different unifloral honeys were also examined. All three honeys enhanced (p < 0.05) growth and activity of the five intestinal Bifidobacterium spp. Their effect on other organisms of the intestinal microflora was selective. Growth of C. perfringens and E. aerofaciens was inhibited (p < 0.05) in the presence of honey and further inhibited when co-cultured with Bifidobacterium spp. Bifidobacterium spp. was not affected.     

Assessing the digestibility of genetically modified soybean: Physiologically based in vitro digestion and fermentation model

Gastrointestinal digestibility of new proteins inserted in food supply is one of significant parameters for assessing safety of genetically modified (GM) foods on the assumption that digestive stability is undesirable. Digestive stability of GM soybean was evaluated under the physiologically based in vitro digestion model. Electrophoresis was used to follow the in vitro sequential digestions/fermentation procedure and Western blotting was employed to confirm the new protein in GM soybean.CP4EPSPS newly expressed in GM soybean was completely digested in 15 s in the gastric fluid in this model. In the assay of fermentation of new protein, CP4EPSPS was also complete degraded and no fermentation products were found during 24 h of colon fermentation. Results from this study suggested that CP4EPSPS in GM soybean does not have a potential allergenicity due to its complete digestion within a very short time in gastric fluid. No formation of colonic protein fermentation products confirms that new protein is not capable of initiating colon cancer.     

Phenotypic and genotypic identification of lactic acid bacteria isolated from a small-scale facility producing traditional dry sausages

Aims: A survey on lactic acid bacteria isolated from a small-scale facility producing traditional dry sausage. A first report on LAB in raw material, products and processing equipment.Methods and Results: A total of 88 isolates were identified phenotypically and genotypically. Phenotypic characterization at the species level indicated that 36 (40.9%) were Lactobacillus sakei, 27 (30.68%) were Enterococcus faecium, 14 (15.90%) were “Enterococcus seriolicida”, 10 (11.36%) were Enterococcus faecalis and 1 (1.13%) was Leuconostoc mesenteroides subsp. mesenteroides/dextranicum 2. In general, genotypic identification correlated well with phenotypic classification since it indicated 36 Lb. sakei, 22 Ec. faecium, 16 Lactococcus garvieae (senior synonym of Ec. seriolicida), 11 Vagococcus carniphilus and 1 Ln. mesenteroides subsp. mesenteroides. Two isolates were assigned as Enterococcus spp.Conclusions: While Ec. faecium, Vc. carniphilus and Lc. garvieae were the predominant species isolated from processing equipment and raw material, Lb. sakei species became the predominant species during fermentation of the product.Significance and Impact of the Study: This study constitutes the first step in the designing process of LAB starter cultures endogenous to the small-scale facility in order to protect the typical organoleptic characteristics of its traditional dry sausage. Otherwise, the presence of undesirable micro-organisms in the processing equipment emphasizes the necessity of improving the general hygienic conditions of sausage production in this facility.     

Effect of high pressure thermal sterilization on the formation of food processing contaminants

The use of high pressure thermal sterilization (HPTS) as an emerging technology for the sterilization of foods could be a big turning point in the food industry. HPTS can result in a better overall food quality, lower thermal load applied to the product and less unwanted food processing contaminants (FPCs) as e.g. furan and monochloropropanediol/-esters.Hence, within the EU FP7 founded Prometheus-project HPTS treatments were performed for selected food systems. Therefore, two spore strains were tested, the Geobacillus stearothermophilus and the Bacillus amyloliquefaciens, in the temperature range from 90 to 121 °C at 600 MPa. The treatments were carried out in different fish system and ACES-buffer. The treatment at 90 and 105 °C showed that the G. stearothermophilus is more pressure sensitive than the B. amyloliquefaciens. The formation of FPCs was monitored during the sterilization process and compared to the amounts found in retorted samples of the same food systems. Depending on the food system the amounts of furan could be reduced between 71 and 97% for the tested temperature pressure combination even at sterilization conditions of F₀-value 7 min.Industrial relevanceThe high pressure thermal sterilization (HPTS) process is an emerging technology to produce high quality low acid food products, which are shelf-stable at ambient temperature. In addition the consumer today demands foods which are minimally processed and are healthy and safe. However, an industrial scale process has not yet been implemented.The work in this paper shows different temperature combinations (90 to 121 °C) at 600 MPa and their influence on the endospore inactivation and also on the formation of unwanted food process contaminants (FPCs), such as furan and monochloropropanediol/-esters, in comparison to retorting. The use of HPTS could lead to shorter process times and a means by which a better quality of the foods could be achieved.     

Pressure–ohmic–thermal sterilization: A feasible approach for the inactivation of Bacillus amyloliquefaciens and Geobacillus stearothermophilus spores

The efficacy of a pressure–ohmic–thermal sterilization (POTS) for Bacillus amyloliquefaciens and Geobacillus stearothermophilus spore inactivation was investigated. Spores (2.5 × 10⁸ cfu/ml) were inoculated in 0.1% NaCl solution (pH 5.0 and 7.0), green pea puree (pH 6.1), carrot puree (pH 5.0) or tomato juice (pH 4.1). Samples were ohmically (50 V/cm) treated at 600 MPa and 105 °C for various holding times using a laboratory-scale high-pressure processor. B. amyloliquefaciens and G. stearothermophilus spores suspended in 0.1% NaCl solution (pH 7.0) were inactivated by 4.6 and 5.6 log, respectively, for a 30-min holding time. B. amyloliquefaciens and G. stearothermophilus spores in tomato juice were reduced by 3.1 and 4.8 log, respectively, for a 10-min holding time. Spore germination was highest in the G. stearothermophilus suspended in 0.1% NaCl solution (pH 7.0). POTS treatment appears to be a potent method for inactivating pressure–thermal resistant bacterial spores.Industrial RelevanceFood industry is interested in developing superior quality low-acid shelf-stable foods. This study evaluated the pressure–ohmic–thermal sterilization (POTS) for the inactivation of Bacillus amyloliquefaciens and Bacillus stearothermophilus endospores. The impact of food matrices and acidity on the spore resistance was also investigated. Knowledge gained from the study will help the food processors for understanding the importance of various POTS treatment parameters for sterilization of low-acid foods.     

The effect of container type on the growth of yeast and lactic acid bacteria during production of Sethemi,South African spontaneously fermented milk

Sethemi, a South African traditional fermented milk, was prepared in the laboratory by spontaneously fermenting raw milk in four different types of containers; namely, a clay pot, gourd, nickel jar and plastic bowl. The development of bacteria and yeasts in the different containers was followed by taking samples at 24 h intervals for 7 days. The predominating microorganisms in all cases were the aerobic mesophilic bacteria, lactobacilli–leuconostocs (LAB on MRS) and lactococci (LAB on M17). No significant (p > 0.05) differences were found in the number of microorganisms between the different containers. However, there were significant (p < 0.05) differences with respect to the types of dominant yeast species, and the diversity of yeast species. The least time to attain maximum LAB counts was recorded for the nickel container. In milk fermented in the clay pot and gourd the most dominant yeast species were Debaryomyces hansenii and Saccharomyces cerevisiae, respectively, while Cryptococcus curvatus predominated in both the nickel and plastic containers. The highest yeast diversity was obtained from milk samples fermented in the clay pot represented by 15 species. Of the 23 species isolated from all the containers and raw milk, only D. hansenii, Cryptococcus humicola and Kluyveromyces marxianus were isolated from both raw and naturally fermented milks of all containers. The use of different types of containers therefore influenced the diversity of yeasts in the fermented milk and may influence the characteristics of the fermented milk product. The clay pot offered the greatest yeast diversity suggesting that it could be the best suited for preparing traditional fermented milk.     

Probiotic properties of folate producing Streptococcus thermophilus strains

This study aimed at assessing the probiotic potential of two high folate producing Streptococcus thermophilus strains (RD102 and RD104) isolated from Indian fermented milk products by both in vitro and in vivo tests. These strains were able to survive at pH 2.5 and 2% bile with a good bile salt hydrolase activity, cell surface hydrophobicity and sensitivity to most of the clinically important antibiotics. On evaluation for gastrointestinal transit tolerance these showed a viable count of 5 log cfu mL^?1 and 7 log cfu mL^?1, respectively in simulated gastrointestinal juice of pH 2.0 and 2% bile. During the in vivo feeding trial in mice the strains showed a viable count of about 7 log cfu g^?1 faeces and 6 log cfu g^?1 of large intestine, respectively. These strains were hence observed to possess favorable strain specific probiotic properties and have the potential to be a source of novel probiotics.     

Effects of high pressure treatment on glycolytic enzymes of Lactococcus lactis subsp. lactis,Streptococcus thermophilus and Lactobacillus acidophilus

High pressure processing (HPP) reduces the glycolytic activity of lactic acid bacteria (LAB) and provides a means to control further production of acidic metabolites in fermented dairy products during storage. However, there is limited information on the effects of HPP on specific enzymes of dairy starter bacteria responsible for the metabolism of lactose. The aim of this study was to determine pressure-induced inactivation of glycolytic enzymes in Lactococcus lactis subsp. lactis C10, Streptococcus thermophilus TS1 and Lactobacillus acidophilus 2400. Cultures were grown for 16 h in M17 or MRS broth containing 5% (w/v) lactose at pH 6.5 (maintained by addition of 10 M NaOH). The cells were harvested by centrifugation, washed and resuspended in 100 mM phosphate buffer (pH 6.5) and pressure-treated at 300 and 600 MPa (≤ 22 °C, 5 min). The ability of pressure-treated resting cells of Lactococcus, incubated with 5% (w/v) lactose at 30 °C, to ferment lactose was evaluated by determining titratable acidity (TA) during incubation. The activities of phospho-β-galactosidase (P-β-gal), β-galactosidase (β-gal) and lactate dehydrogenase (LDH) were determined in cell-free extracts of untreated and pressure-treated cells. Resting cells of Lactococcus treated at 600 MPa had a substantially lower rate of acidification than the controls and those treated at 300 MPa. Both P-β-gal and β-gal were significantly inactivated (p < 0.01) in the starter cultures treated at 300 or 600 MPa. The LDH in Lactococcus and Lactobacillus was highly resistant to pressure treatment at 300 MPa. In contrast, the LDH in Streptococcus was almost completely inactivated at ≥ 300 MPa.Industrial relevanceContinuing production of acidic metabolites in fermented dairy products during storage can be a technological challenge that adversely affects product quality. The current study demonstrates that high pressure processing (HPP) offers the potential of controlling this problem by inactivation of glycolytic enzymes in various mesophilic and thermophilic starter cultures. The findings of this research will assist in establishing optimised operating parameters for HPP treatment of cultured products to extend shelf-life, by reducing acid production during storage.     

Evaluation of enzymic potential for biotransformation of isoflavone phytoestrogen in soymilk by Bifidobacterium animalis,Lactobacillus acidophilus and Lactobacillus casei

Three strains of Lactobacillus acidophilus, two of Lactobacillus casei and one of Bifidobacterium were screened for β-glucosidase activity using ρ-nitrophenyl-β-d-glucopyranoside as a substrate and their potential for the breakdown of isoflavone glucosides to the biologically active aglycones in soymilk. Isoflavones quantification with HPLC and β-glucosidase activity were performed after 0, 12, 24, 36, and 48 h of incubation in soymilk at 37 °C. All six micro-organisms produced β-glucosidase, which hydrolysed the predominant isoflavone β-glucosides. There was a significant increase and decrease (P < 0.05) in the concentration of isoflavone aglycones and glucosides, respectively, in fermented soymilk. Based on the concentration of isoflavones during peak β-glucosidase activity, the hydrolytic potential was calculated. L. acidophilus 4461 had the highest aglycone concentration of 76.9% after 24 h of incubation, up from 8% in unfermented soymilk (at 0 h). It also had the best isoflavone hydrolytic index of 2.01, signifying its importance in altering the biological activity of soymilk.     

Influence of daily consumption of synbiotic soy-based product supplemented with okara soybean by-product on risk factors for cardiovascular diseases

This study aimed to investigate the effect of a synbiotic fermented soy product supplemented with okara (a by-product from soybean) on cardiovascular disease risk markers in healthy men. In a randomized, double-blinded, placebo controlled trial, thirty-six normocholesterolemic men were assigned to two groups. Subjects consumed daily 100 g of soy-based product fermented with Lactobacillus acidophilus La-5, Bifidobacterium animalis subsp. lactis Bb-12, and Streptococcus thermophilus (starter culture) (synbiotic group — S) (n = 18) or 100 g of unfermented soy-based product (placebo group — P) (n = 18) for 8 weeks. Fasting blood samples and anthropometric measurements were collected at the baseline (T₀), the end of week 4 (T₄), and the end of week 8 (T₈). Serum lipids, C-reactive protein, fibrinogen, and electronegative LDL were also analysed on T₀, T₄, and T₈. During the period of daily soy-based product consumption (from T₀ to T₈) the LDL-C mean decreased significantly (p < 0.05) in group S, resulting in a significant (p < 0.05) improvement of the LDL-C/HDL-C ratio. Comparing mean differences (T₈–T₀) between the two groups, the trend of LDL-C and LDL-C/HDL-C ratio reductions was higher in group S (14.1 mg/dL and 0.38 mg/dL, respectively) than group P (4.9 mg/dL and 0.17 mg/dL, respectively) (p > 0.05). Our results suggest limited lipid-lowering effects of synbiotic soy-based product supplemented with okara on cardiovascular risk markers in normocholesterolemic men.     

Antibacterial potential of Enterococcus faecium strains isolated from ewes’ milk and cheese

The study was conducted to evaluate the antibacterial activity of three bacteriocin-producing Enterococcus faecium strains (TW15, TW20 and TW22) isolated from ewes’ milk and cheese sampled in the Patagonian region of Argentina. The strains were tested against spoilage and pathogens microorganisms showing antimicrobial activity towards 4 strains of Listeria monocytogenes, one strain of Listeria innocua and 2 strains of Staphylococcus aureus. E. faecium TW15, E. faecium TW20 and E. faecium TW22 were sensitive to vancomycin. Furthermore, investigation of virulence factors revealed the absence of the genes encoding them. The bacteriocin-like substances (BLISs) produced by the 3 strains were thermostable, pH resistant and can be expressed even in the presence of NaCl (3.0 g/100 g). Moreover, they prove to have a bactericidal mode of action. Results from physicochemical and biochemical characteristics of BLIS produced by these E. faecium strains make them potential candidates to aid in preservation of foods.