Leuconostoc Mesenteroides Strain Research Articles

A mixture design approach to develop new starter formulation for Lben: Key aroma compounds, physical, chemical and sensory properties of the product

The study investigated the evolution of the physicochemical and sensory properties of Lben fermented milk inoculated with different starter formulations. The aim was to determine the optimal starter culture formula for Lben production using different combinations of four strains, including three strains of Lactococcus lactis subsp. lactis with strain codes A, E and F and one strain of Leuconostoc mesenteroides subsp. mesenteroides with strain code C. While individual strains had previously demonstrated significant technological and organoleptic properties their interaction in mixtures had not been explored. In the study, a response surface methodology (mixture design approach) was applied to evaluate the effects of the interactions between strains on the physicochemical, antioxidant, volatile, and sensory properties of Lben, a fermented milk. In addition, product optimization using ridge analysis was performed to determine the ideal strain mixture formulation based on the sensory properties of Lben. The optimization goal for odor, taste, consistency, and overall preference was set to maximize their values. A high desirability score of 0.832 was achieved with the following percentage distribution: 34.39% for L. lactis E, 42.38% for L. lactis A, 10% for L. lactis F, and 13.23% for Leuc. mesenteroides C.

Production of Dextran by Leuconostoc mesenteroides Isolated from Home Made Fermented Foods

Dextran gum has important medicinal applications. The study was aimed to produce the dextran from Leuconostoc mesenteroides isolated from home made fermented foods. Two strains of Leuconostoc mesenteroides (LM-1 and LM-2) were isolated from chilli pickle and sauerkraut by enrichment culture technique. The isolates were subjected to dextran gum production using standard sucrose medium and modified medium made with sugar cane juice and & liquid jaggery. Dextran gum produced by each isolate with different medium combinations was extracted and purified and subjected to conformity tests. The dextran produced by isolates was found to be viscous and soluble in water. The isolate LM1 showed highest yield of 3.50 g / 100ml with sugarcane juice medium. Sugarcane juice can be used as a source of sucrose which is economically affordable. However, more studies should be carried out to explore the process of dextran gum production

Potential of γ-Aminobutyric Acid-Producing Leuconostoc mesenteroides Strains Isolated from Kimchi as a Starter for High-γ-Aminobutyric Acid Kimchi Fermentation.

γ-Aminobutyric acid (GABA)-producing Leuconostoc mesenteroides K1501 and K1627, isolated from kimchi, exhibited the highest GABA production in 1% monosodium glutamic acid. Both strains showed high survival rates of approximately 87% in artificial gastric juice (pH 3.0) and >80% in 0.1% artificial bile salt fluid. The survival rate was approximately 28% in 0.3% artificial bile salt fluid and 0% in 0.5% artificial bile salts. Both strains showed excellent adhesion to intestinal epithelial cells (>99%). Furthermore, it was observed that growth was not inhibited at 2% salt concentration; however, it was slightly retarded at salt concentrations of 3% and 4%. Moreover, L. mesenteroides K1501 and K1627 inhibited the growth of certain species of Lactobacillus, whose presence in kimchi fermentation is undesirable. Therefore, L. mesenteroides K1501 and K1627 have the potential to be used as starter organisms for functional GABA-rich kimchi.

Probiogenomics of Leuconostoc Mesenteroides Strains F-21 and F-22 Isolated from Human Breast Milk Reveal Beneficial Properties.

Bacteria of the Leuconostoc genus are Gram-positive bacteria that are commonly found in raw milk and persist in fermented dairy products and plant food. Studies have already explored the probiotic potential of L. mesenteroides, but not from a probiogenomic perspective, which aims to explore the molecular features responsible for their phenotypes. In the present work, probiogenomic approaches were applied in strains F-21 and F-22 of L. mesenteroides isolated from human milk to assess their biosafety at the molecular level and to correlate molecular features with their potential probiotic characteristics. The complete genome of strain F-22 is 1.99Mb and presents one plasmid, while the draft genome of strain F-21 is 1.89Mb and presents four plasmids. A high percentage of average nucleotide identity among other genomes of L. mesenteroides (≥ 96%) corroborated the previous taxonomic classification of these isolates. Genomic regions that influence the probiotic properties were identified and annotated. Both strains exhibited wide genome plasticity, cell adhesion ability, proteolytic activity, proinflammatory and immunomodulation capacity through interaction with TLR-NF-κB and TLR-MAPK pathway components, and no antimicrobial resistance, denoting their potential to be candidate probiotics. Further, the strains showed bacteriocin production potential and the presence of acid, thermal, osmotic, and bile salt resistance genes, indicating their ability to survive under gastrointestinal stress. Taken together, our results suggest that L. mesenteroides F-21 and F-22 are promising candidates for probiotics in the food and pharmaceutical industries.

Leuconostoc mesenteroides WHH1141 ameliorates ovalbumin-induced food allergy in mice.

Food allergy (FA) is acknowledged as a significant public health and food safety issue, due to its manifestation as an amplified immune reaction to food antigens. Recently, probiotics within Lactobacillus and Bifidobacterium have been highlighted as a promising strategy against allergic disease by modulating the balance of Th1/Th2 responses. However, the allergy-alleviating effects of probiotic Leuconostoc mesenteroides strains are unknown. Therefore, this study investigated the potentials of eleven L. mesenteroides strains on the Th1/Th2 balance in vitro by evaluating the expression patterns of interferon-gamma (IFN-γ) (Th1 cytokine) and interleukin-4 (IL-4) (Th2 cytokine) in mesenteric lymph node-derived lymphocytes from ovalbumin (OVA)-sensitized mice. Among strains, WHH1141 incubation caused the highest IFN-γ/IL-4 ratio. Oral administration of WHH1141 (1×109 CFU/mL) in the OVA-induced FA mouse model for 40 days improved the weight loss and FA pathological symptoms and normalized the serum immunoglobulin E levels. Meanwhile, the OVA-induced elevated gene expressions of cytokines (IL-4, IL-5, and IL-13) and tight-junction proteins (ZO-1 and Occludin) and levels of cytokines (IL-4, IL-5, and IL-13) and histamine in the jejunum were restored by WHH1141. Furthermore, WHH1141 reversed the reduced gut microbial diversity and short-chain fatty acid (SCFA) levels, specifically increased Bacteroidota abundance, and decreased Firmicutes abundance in OVA-induced mice. Overall, these findings suggest that WHH1141 exerts FA-alleviating effects on OVA-induced mice, which is involved with the inhibition of the jejunal Th2 immune responses and the modulation of gut microbiome composition and SCFA productions. PRACTICAL APPLICATION: Leuconostoc mesenteroides WHH1141 with FA-alleviating potentials may be considered a promising approach in the mitigation of FA symptoms.

The Potential of Leuconostoc mesenteroides Strain LK-151 to Inhibit in vivo Salmonella Infection

The purpose of the study was to evaluate the efficacy of the probiotic Leuconostoc mesenteroides strain LK-151 isolated from fermented camel milk against Salmonella infection in BALB/c mice. A total of 50 mice were divided into five groups of n = 10 per group and subjected to different treatments. Infecting mice with Salmonella led to a significant decrease in feed intake and body weight. This occurred simultaneously with the appearance of symptoms on day 3 of the infection with the recording of one death after 6 days. The pathogenic cells were detected at a high rate in the feces, which reached 7.045 Log10 CFU/g on day 7 post-infection. Histological studies revealed significant damage to the ileum and the liver. Whereas, administering mice with the probiotic strain for one week before being infected with S. Typhimurium avoided body weight loss, and feed intake was not affected. The probiotic was able to suppress the growth of the pathogen and offer protection to the ileum. However, localized congestion was noted in the liver of some mice. It was also found that giving the probiotic to the mice during the infection did not improve the tested parameters. It can be concluded that the strain under study has probiotic potential and can protect against Salmonella infection.

Lytic bacteriophages affect the population dynamics of multi-strain microbial communities.

Background: Lytic bacteriophages infect and lyse bacteria and, as a by-product, may affect diversity in microbial communities through selective predation on abundant bacterial strains. We used a complex dairy starter named Ur to investigate population dynamics of Lactococcus lactis, Lactococcus cremoris and Leuconostoc mesenteroides strains in terms of constant-diversity and periodic selection models. Methods: To mimic the starter Ur, we designed blends of 24 strains representing all eight previously identified genetic lineages in the starter culture. The blends were propagated by daily transfers in milk for over 500 generations in the presence or absence of a cocktail of lytic bacteriophages. The relative abundance of genetic lineages of L. lactis, L. cremoris and Lc. mesenteroides strains present in the complex blend, as well as phage presence, were monitored. Results: Control blends without phage predation showed decreased strain diversity, leading to a stable state due to the domination of the fittest strain(s) of a particular lineage according to periodic selection dynamics. However, in phage-challenged blends, predation caused a large shift in the microbial composition by killing the fittest and sensitive strains. Conclusion: It was demonstrated that phage-challenged blends maintained their diversity at the level of genetic lineages, thus providing experimental support for the constant-diversity dynamics model in a complex microbial community.

Glycosyltransferases Expression Changes in Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293 Grown on Different Carbon Sources.

Leuconostoc mesenteroides strains are common contributors in fermented foods producing a wide variety of polysaccharides from sucrose through glycosyltransferases (GTFs). These polymers have been proposed as protective barriers against acidity, dehydration, heat, and oxidative stress. Despite its presence in many traditional fermented products and their association with food functional properties, regulation of GTFs expression in Ln. mesenteroides is still poorly understood. The strain Ln. mesenteroides ATCC 8293 contains three glucansucrases genes not found in operons, and three fructansucrases genes arranged in two operons, levLX and levC-scrB, a Glycoside-hydrolase. We described the first differential gene expression analysis of this strain when cultivated in different carbon sources. We observed that while GTFs are expressed in the presence of most sugars, they are down-regulated in xylose. We ruled out the regulatory effect of CcpA over GTFs and did not find regulatory elements with a direct effect on glucansucrases in the condition assayed. Our findings suggest that only operon levLX is repressed in xylose by LexA and that both fructansucrases operons can be regulated by the VicK/VicR system and PerR. It is essential to further explore the effect of environmental conditions in Ln. mesenteroides bacteria to better understand GTFs regulation and polymer function.

16S rRNA gene sequencing and MALDI TOF mass spectroscopy identification of Leuconostoc mesenteroides isolated from Algerian raw camel milk

BackgroundEighty-three strains of Leuconostoc mesenteroides were isolated from Algerian raw camel milk. Based on morphological, biochemical, and physiological characters tests, strains were identified as Ln. mesenteroides subsp. mesenteroides. Seven strains had a remarkable antagonistic and probiotic characterization. The present study aims at identifying these strains by means of 16 s rRNA gene sequencing and Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), extending phenotypic and genotypic studies done previously. ResultsThe phyloproteomic dendrograms of the studied strains based on MALDI-TOF MS provided the same identification with more intraspecific information from the 16S rRNA gene sequencing based on phylogenetic analysis. The latter were in agreement with the previous biochemical/physiological identification, the seven isolated strains were Ln. mesenteroides subsp. mesenteroides. ConclusionsRemarkably, MALDI-TOF MS fingerprinting was found to be effective enough as 16S rRNA gene sequencing identification, allowing faster and more reliable analysis than biochemical/physiological methods.

In Silico Analysis of the Dextransucrase Obtained From Leuconostoc mesenteroides Strain IBUN 91.2.98.

The DSR-IBUN dextransucrase produced by Leuconostoc mesenteroides strain IBUN 91.2.98 has a short production time (4.5 hours), an enzymatic activity of 24.8 U/mL, and a specific activity of purified enzyme 2 times higher (331.6 U/mg) than that reported for similar enzymes. The aim of this study was to generate a structural model that, from an in silico approach, allows a better understanding, from the structural point of view, of the activity obtained by the enzyme of interest, which is key to continue with its study and industry application. For this, we translated the nucleotide sequence of the dsr_IBUN gene. With the primary structure of DSR-IBUN, the in silico prediction of physicochemical parameters, the possible subcellular localization, the presence of signal peptide, and the location of domains and functional and structural motifs of the protein were established. Subsequently, its secondary and tertiary structure were predicted and a homology model of the dextransucrase under study was constructed using Swiss-Model, performing careful template selection. The values obtained for the model, Global Model Quality Estimation (0.63), Quality Mean (-1.49), and root-mean-square deviation (0.09), allow us to affirm that the model for the enzyme dextransucrase DSR-IBUN is of adequate quality and can be used as a source of information for this protein.

An exopolysaccharide from Leuconostoc mesenteroides showing interesting bioactivities versus foodborne microbial targets

An exopolysaccharide (EPS_B3) produced by a Leuconostoc mesenteroides strain isolated from a semi-hard Italian cheese was chemically and biologically characterized. HPLC-SEC, NMR, FT-IR and monosaccharide composition experiments were performed. Antimicrobial, antibiofilm, bifidogenic, antioxidant, and DNA-protective activity of EPS_B3 were also studied. Results revealed that EPS_B3 was a mixture of two high-molecular-weight dextran with low branching degree. Moreover, EPS_B3 displayed significant antibacterial activity against eight foodborne pathogens and inhibited biofilm formation by Listeria monocytogenes. EPS_B3 also evidenced bifidogenic activity, stimulating the growth of three probiotic bifidobacteria, and improving the tolerance of Bifidobacterium animalis subsp. lactis to oxygen stress. It also protected plasmid DNA from hydrogen peroxide damage. Only limited antioxidant capacity was observed.In conclusion, data suggest that EPS_B3 might be exploited in the context of functional foods especially for its marked antimicrobial activity as well as for the ability to improve the viability of bifidobacteria in probiotic foods. However, further studies should be carried out to assess the ability of EPS_B3 to reach intact the target site (i.e., gastrointestinal tract) to consider the possibility of use it as a new functional ingredient in foods.

Selection of Lactic Acid Bacteria Isolated from Cocoa and Cassava Fermentation as Potential Probiotic for Pathogenic Microorganisms Control in Poultry Farming

Aims: The overuse of antibiotics in animal farming sector is leading to an increase drug resistant bacteria rate. This situation makes it difficult to treat pathologies in both humans and animals. The aim of this study was to assess some probiotic profiles of lactic acid bacteria strains isolated from cocoa fermentation and traditional cassava ferment for possible use as potentially probiotic strains for the monitoring of pathogenic microorganisms in poultry farming.
 Methodology: Thus, a total of 267 lactic acid bacteria strains were tested for analysis of the antibacterial activity against the growth capacity of Salmonella and E. coli isolates. Probiotic properties of Lactic acid bacteria were consisted of acidification capacity, resistance to acid shock and to salt bile containing in culture medium and capacity to produce proteolytic and lipolytic enzymes.
 Results: Among them, 25 strains have induced the high bacterial growth inhibition against these pathogenic bacteria with inhibition zone diameters ranged from 9 to 27 mm. Among these strains, 20 isolates showed high resistance to acid shock at pH ≥ 4 and six strains were able to grow at pH 3.5 with survival rate range from 30 % to 89 %. Moreover, six of these strains, including four isolates of Lactobacillus plantarum (T1GB8, T11AB17, LAB26, LAB 127), one strain of Leuconostoc mesenteroides (T0AB9) and one isolate of Enterococcus facium (LAB18), have shown capacity to growth with 1 % of bile salts in the medium. Even better, these strains exhibited capacity to produce proteolytic and lipolytic enzymes with halo around the well diameters reached 29 mm for some strains.
 Conclusion: This study shows the possibility of use probiotics lactic acids bacteria as antibiotics alternative in poultry sector to reduce some avian pathologies affecting the poultry sector in Côte d'Ivoire.

Processing properties of yogurt as affected by the EPS produced by Leuconostoc mesenteroides XR1

SummaryThe aim of this study was to examine the fermentation characteristics of a novel Leuconostoc mesenteroides strain (XR1) and to investigate the effect of XR1 exopolysaccharides (EPS) on the microstructure, texture and rheological properties of yoghurt. The novel Leuconostoc mesenteroides strain (XR1) was isolated from wild kefir grains obtained from Xinjiang Province. The results showed that XR1 had good EPS production capacity and favourable fermentation performance. The addition of XR1 EPS to fermented milk effectively improved the water‐holding capacity (WHC) of the fermented milk and changed its microstructure. In subsequent fermentation studies, the XR1 strain was found to be a compatible strain, and the steric barrier formed between XR1 EPS and the fermented milk proteins enhanced its viscoelastic properties. Rheology studies indicated that fermented milk supplemented with EPS possessed a higher modulus (G’, G’’ ) and complex viscosity. Thus, these results indicate that XR1 EPS are useful as a natural organic additive that can replace chemical additives in dairy products.

Short Communication: Dextran production using Leuconostoc mesenteroides strains isolated from Borassus flabellifer sap

Abstract. Ma'unatin A, Harijono, Zubaidah E, Rifa'i M. 2022. Short Communication: Dextran production using Leuconostoc mesenteroides strains isolated from Borassus flabellifer sap. Biodiversitas 23: 1154-1158. Exopolysaccharide (EPS) is a carbohydrate polymer secreted by several bacteria in their growth period, including Lactic Acid Bacteria (LAB). Dextran is a type of EPS produced by Leuconostoc mesenteroides and is used widely in the food and pharmaceutical fields. Therefore, this study aimed to evaluate the potency of two strains of L. mesenteroides isolated from Borassus flabellifer L. (lontar) sap, namely L. mesenteroides N5 and N7 for dextran production using the MRS broth medium supplemented with sucrose at varying concentrations of 5, 10, and 15% (w/v). The results showed that L. mesenteroides N5 produced dextran of 14.53 g/L in medium with 15% sucrose, while L. mesenteroides N7 yielded 13.16 g/L at 10% sucrose. The characteristics of selected dextran showed that it contains 89.93% total carbohydrate, 2.33% protein and has a surface structure with tight pore for dextran N5 while the dextran N7 contains 87.84% total carbohydrates, 2.22% protein and has looser porous surface structure.

Chemical Synthesis and Evaluation of Exopolysaccharide Fragments Produced by Leuconostoc mesenteroides Strain NTM048.

Exopolysaccharides (EPSs) occur widely in natural products made by bacteria, fungi and algae. Some EPSs have intriguing biological properties such as anticancer and immunomodulatory activities. Our group has recently found that EPSs generated from Leuconostoc mesenteroides ssp. mesenteroides strain NTM048 (NTM048 EPS) enhanced a production of mucosal immunoglobulin A (IgA) of mouse. Herein, we described the synthesis and evaluation of the tetrasaccharide fragments of NTM048 EPS to obtain information about the molecular mechanism responsible for the IgA-inducing activity.

Influence of Culture Media Formulated with Agroindustrial Wastes on the Antimicrobial Activity of Lactic Acid Bacteria.

The discarding of wastes into the environment is a significant problem for many communities. Still, food waste can be used for lactic acid bacteria (LAB) growth. Here, we evaluated three growth media equivalent to de Mann Rogosa Sharpe (MRS), using apple bagasse, yeast waste, fish flour, forage oats, and cheese whey. Cell-free supernatants of eight LAB strains were tested for antimicrobial activity against nine indicator microorganisms. The supernatants were also evaluated for protein content, reducing sugars, pH, and lactic acid concentration. Cell-free supernatants from fish flour broth (FFB) LAB growth were the most effective. The strain Leuconostoc mesenteroides PIM5 presented the best activity in all media. L. mesenteroides CAL14 completely inhibited L. monocytogenes and strongly inhibited Bacillus cereus (91.1%). The strain L. mesenteroides PIM5 consumed more proteins (77.42%) and reducing sugars (56.08%) in FFB than in MRS broth (51.78% and 30.58%, respectively). Culture media formulated with agroindustrial wastes positively improved the antimicrobial activity of selected LAB, probably due to the production of antimicrobial peptides or bacteriocins.

Isolation and identification of psychrotrophic lactic acid bacteria in godo, the traditional fermented soy food in Japan.

Godo is a traditional fermented soy food made in Aomori prefecture, Japan. It is mainly made of soybeans, rice koji, and salt. Since godo ripens during the long and severe winter in northeast Japan, it is assumed that lactic acid bacteria inhabiting godo have cold tolerance. We aimed to investigate the presence or absence of psychrotrophic lactic acid bacteria in godo. The viable counts of estimated lactic acid bacteria ranged from 106 to 108 cfu/g. In addition, aerobic and anaerobic microorganisms were detected in four godo products though the microbial population differed from sample to sample. Twenty-two bacterial strains were able to be isolated from godo, and all of the isolated strains were Gram-positive and catalase-negative. Some of the isolates grew well at 10°C. The carbohydrate fermentation profile of the selected three strains was determined by API50 CHL analysis. These strains were identified as Leuconostoc mesenteroides, and Latilactobacillus sakei by 16S rRNA gene sequence analysis. Leuconostoc mesenteroides strains HIT231 and HIT252, and Latilactobacillus sakei strain HIT273 could grow at 5°C in MRS broth, but their optimum growth temperature was 20°C-30°C. These results suggest that psychrotrophic lactic acid bacteria presumed to be derived from rice koji are present in godo, which is one of the factors in the low temperature ripening of godo in winter.

Chufa Drink: Potential in Developing a New Plant-Based Fermented Dessert.

Plant-based foods with desirable texture and nutritional value have attracted considerable interest from consumers. In order to meet the growing demand for more sustainable and health-focused products, new sources for plant-based products are needed. In this study, we aimed to develop an innovative plant-based dessert based on the underutilized crop chufa tubers (Cyperus esculentus). The chufa extract was fermented with plant-adapted lactic acid bacteria and formulated with the purpose of imitating the Danish summer dessert “cold butter-milk soup”. The effect of various bacterial fermentations and formulations on steady and oscillatory rheology, stability, dry matter, pH, and sugar profile of the product were studied and compared to a commercial cold buttermilk soup sample. A strain of Leuconostoc mesenteroides was found to create the most similar taste to a commercial sample. By adding lemon juice, sucrose, xanthan gum, and vanilla to the fermented chufa drink, the drink was found to mimic the pH, texture, acid profile, and stability of a commercial dairy-based sample, while containing a lower concentration of carbohydrates.

Some potential beneficial properties of Lacticaseibacillus paracasei subsp. paracasei and Leuconostoc mesenteroides strains originating from raw milk and kefir grains

In this study, some potential beneficial properties and probiotic characteristics of Lacticaseibacillus paracasei subsp. paracasei and Leuconostoc mesenteroides strains were investigated in 48 isolates, which were isolated from raw cow's and sheep's milk and kefir grains. The study aimed to determine the antimicrobial properties, antibiotic resistance profiles, antioxidant properties, proteolytic activities, bile salt resistance levels, and bile salt deconjugation activities of L. paracasei and Leu. mesenteroides strains. L. paracasei strains showed a higher antimicrobial activity profile than Leu. mesenteroides strains. L. paracasei strains were not sensitive to novobiocin (5 µg) and bacitracin (10 µg), while Leu. mesenteroides ZT8 showed resistance only to polymyxin B (300 µg). L. paracasei strains showed higher antioxidant activity compared to Leu. mesenteroides strains. L. paracasei SMM1 strain showed strong growth in the presence of 0.25% bile salt, whereas Leu. mesenteroides ZT8 and Leu. mesenteroides ZX3 showed poor growth. Neither L. paracasei nor Leu. mesenteroides strains were able to develop at 0.5%–1% bile salt concentration. Bile salt deconjugation ability was lower in Leu. mesenteroides strains, and Leu. mesenteroides ZT8 produced deconjugation from taurodeoxycholic acid. It was remarkable that Leu. mesenteroides strains showed higher proteolytic activity. Leu. mesenteroides ZT8 strain showed the highest hydrophobicity. Evaluating the obtained results, it was seen that the characteristics of Leu. mesenteroides and L. paracasei strains differed according to the source and strain from which they were isolated. It was determined that both types were suitable for industrial use. Novelty impact statement Isolation and identification of Lacticaseibacillus paracasei subsp. paracasei and Leuconostoc mesenteroides strains derived from raw milks and kefir grains. Biochemical properties of dairy orgin L. paracasei and Leu. mesenteroides strains. Probiotic potential of L. paracasei and Leu. mesenteroides strains isolated from dairy environment.

ISOLATION OF LACTIC ACID BACTERIA FROM TRADITIONAL MOROCCAN PRODUCTS AND EVALUATION OF THEIR ANTIFUNGAL ACTIVITY ON GROWTH AND OCHRATOXIN A PRODUCTION BY ASPERGILLUS CARBONARIUS AND A. NIGER

Different agricultural products, including grapes, are susceptible to contamination and damage by several microorganisms, one being fungi and their mycotoxins such as ochratoxin A. These alterations are a source of food waste and lead to significant economic losses. Thus, new alternatives have been sought in parallel with existing methods. In this work, after isolation, identification by 16S rDNA sequencing and differentiation by Pulsed-Field Gel Electrophoresis (PFGE) of four lactic acid bacteria from different traditional Moroccan food products, antifungal activity was studied against Aspergillus carbonarius and A. niger isolated from Moroccan grapes. Their effect on ochratoxin A production was also assessed. A strain of Lactoccocus lactis ssp. lactis (F) and three strains of Leuconostoc mesenteroides ssp. mesenteroides (I, C, and D) selected from 16 isolated strains were tested. Their antifungal activities against Aspergillus spp. were quite significant, with growth inhibition rates ranging from 28.69% to 53.31%. Likewise, ochratoxin A production by Aspergillus strains was significantly reduced. Indeed, in the presence of the Lactoccocus lactis ssp. lactis (F) strain, this reduction was about 63.90% and 65.12% for A. niger and A. carbonarius, respectively; however, an 89.38% reduction for A. niger and 19.35 % A. carbonarius was achieved for the Leuconostoc mesenteroides ssp. mesenteroides (I) strain. These results revealed strain-dependent antifungal activity. Our study indicates that the use of these lactic acid bacteria can be applied as a biocontrol of fungal growth and mycotoxins production.