Potential Of Lactic Acid Bacteria Research Articles

Unlocking the Potential of Lactococcus lactis subsp. lactis BIONCL17752 strain on Fumonisin B1 production by Fusarium verticillioides

Mycotoxins are the potent toxic chemical agent's linked to food safety, pose a serious risk to human and animal health globally. The management of toxigenic fungi is a challenging task in food and feed industries. The present investigation aimed to use probiotic potentials of lactic acid bacteria (LAB), and fermented cell-free broth as antifungal agents and neutralization of carcinogenic mycotoxin, fumonisin B1 (FB1) in food and feed considered as “turned waste into treasure”. We strived to investigate the probiotic potential of Lactococcus lactis subsp. lactis BIONCL17752 strain on prevention of growth and neutralization of FB1 produced by Fusarium verticillioides BIONCL4 strain to emulate as as a food grade bio-preservative. The BIONCL17752 strain exhibited excellent inhibitory activity against BIONCL4 strain. It was cultivated in MRS medium, and obtained cells pellet (CP) and cell-free supernatant (CFS) was lyophilized, and used for their antifungal activity against BIONCL4 strain. The minimum fungicidal concentration (MFC) determined as 12.5 μg/mL. Nevertheless, CFS assessed for neutralization of FB1 production which exhibited complete inhibition and downregulation of FB1 encoding FUM1 gene expression using quantitative real-time PCR (qPCR). Furthermore, CFS induced transcriptomic studies against BIONCL4 strain endorsed a significant downregulation of virulence, FB1, fusaric acid, fusarin, and chitin biosynthetic pathway genes. The CFS and cells reticent spore germination and FB1 production in the range of 40–61% and 74–85%, respectively under stored maize for 60 days. The current findings suggest BIONCL17752 strain apprehend the fungal growth and inhibit the FB1, and other toxigenic molecules biosynthesis, and can be employed as food grade preservative in the food industries to ensure the food safety and human health.

Molecular identification and antifungal potentials of lactic acid bacteria isolated from soil

Molecular identification and antifungal potentials of lactic acid bacteria isolated from soil

POTENTIAL OF LACTIC ACID BACTERIA, ISOLATED FROM SEVERAL SOURCES, TO INHIBIT THE GROWTH OF Candida albicans ATCC10231

ARTICLE HIGHLIGHTS- Lactic acid bacteria have potential to control candidiasis or Candida albicans. - The novelty of this study is to advance the potential of lactic acid bacteria to control candidiasis infection in human, with a view to develop novel LAB-based probiotic candidates with capability to inhibit/prevent infection by C. albicans, the causative agent of candidiasis.ABSTRACTThe main aims of this research were to isolate and identify potential lactic acid bacteria (LAB) inhibitory to Candida albicans. The LAB sources were kimchi, honey and vaginal secrete of healthy women. They were isolated with a view to develop a novel alternative method with reduced use of antifungal agents in the treatment of patients infected by such fungal pathogen. Isolation of the LABs was conducted by applying dilution spread method on de Mann Rogosa Sharpe agar (MRSA) medium supplemented with bromo cresol purple (BCP) indicator. Once purified, they were tested for antagonism against C. albicans in dual culture assays. LAB isolates that showed significant inhibition against the pathogen were identified using 16s rDNA sequences and their sequences were aligned with those of known sequences deposited at the Gene Bank (http://www.ncbi.nlm.nih.gov). The results showed that 46 among more than 100 LABs isolated in this study significantly inhibited the growth of C. albicans in the in vitro dual culture assays, and all showed resistance property to antifungal agent (fluconazole). This indicated that they all have potential to be synergically applied with reduced use of fluconazole in the therapy. The most potential isolates (10 isolates) were closely related to three LAB species, namely Lactobacillus paracasei, Lacticaseibacillus paracasei, and Pediococcus pentosaceus, based on their 16s rDNA sequence similarities with those deposited in the GenBank.

Exploration of Probiotic Potential of Lactic Acid Bacteria from Pentaclethra macrophylla in Okigwe, Imo State, Nigeria

Exploration of Probiotic Potential of Lactic Acid Bacteria from Pentaclethra macrophylla in Okigwe, Imo State, Nigeria

In vitro probiotic potential of lactic acid bacteria isolated from the intestines of Muscovy ducks.

The current study was conducted to isolate, test and characterize molecularly and physiologically lactic acid bacteria from the intestines of Muscovy ducks to evaluate their probiotic potential for poultry farming. Three hundred lactic acid bacteria from the gastrointestinal tract of Muscovy ducks were isolated. The strains were phenotypically characterized by observing cell morphology, performing Gram staining, catalase production, and testing their ability to grow in MRS broth at different temperatures, pH values, NaCl concentrations, bile concentration, and in compatibility tests between strains. Nine strains were selected based on their resilience. Eight strains were identified using molecular techniques. These strains exhibited significant tolerance to acidic pH, bile salts, and NaCl, essential for probiotic function. All isolates inhibited the growth of Salmonella enterica serotype Typhimurium (DT104) and Enteropathogenic Escherichia coli serotype O86:H34 (EPEC), showcasing their antimicrobial potential. Antibiotic susceptibility testing revealed 100% resistance to clindamycin and erythromycin but high susceptibility to ampicillin and vancomycin. Growth was observed at various temperatures, indicating mesophilic characteristics. Compatibility tests confirmed their suitability for probiotic formulations. Genomic analysis identified the strains primarily as Enterococcus. Conclusively, the study identified eight out of nine selected lactic acid bacteria strains from Muscovy ducks as autochthonous probiotics, showing resilience to treatments and compatibility for consortium formulation. These strains are suitable for in vivo testing for potential poultry farming applications. Further research on their molecular mechanisms and in vivo effects is needed.

Probiotic potential of lactic acid bacteria isolated from Ethiopian traditional fermented Cheka beverage

Introduction: Lactic acid bacteria (LAB) are a cluster of microbes distributed in a variety of environments and have potential probiotic activity to improve human well-being. This study was aimed at assessing the probiotic potential of LAB isolated from Cheka, an Ethiopian traditionally fermented beverage.MethodPure isolates obtained from 16 Cheka samples from Konso (n = 8) and Derashe (n = 8) were characterized morphologically, biochemically, and physiologically by considering basic criteria to identify the LAB. The probiotics properties of the LAB were evaluated in vitro at low pH values (2.0 and 3.0), and two bile salt concentrations (0.3 and 0.5%) for 3 and 6 h. The 16 S rRNA gene sequencing was done using an ABI 3730xl sequencer, and the gene sequences were aligned.ResultsOf the 27 pure isolates, 11 isolates were proven to be LAB with non-motile, negative for catalase, and non-spore former characteristics. Based on cultural characteristics and sugar fermentation ability, the 11 isolates were assembled into the genera Lactobacillus (55%), Lactococcus (18%), Pediococcus (18%), and Leuconostoc (9%). At pH 3.0 and a bile salt concentration of 0.3%, isolate ChK-11 showed a better survival rate (97 and 94%) than other isolates [ChK-7 (93 and 80%) > ChD-5 (84 and 76%) > ChD-8 (46 and 36%) > ChK-4 (41 and 34%)] for 6 and 3 h, respectively. According to 16 S rRNA sequencing results, isolates ChK-11 and ChK-7 were found to be Weissella paramesenteroides and Leuconostoc pseudomesenteroides with sequence similarity of 99 and 91%, respectively.ConclusionsIn the present study, probiotic LAB (Weissella paramesenteroides and Leuconostoc pseudomesenteroides) was successfully isolated and sequenced from Cheka samples. The findings of this in vitro study indicated that fermented beverages like Cheka are a source of the LAB with probiotic functional properties. Overall, Weissella paramesenteroides and Leuconostoc pseudomesenteroides isolates, which showed promising probiotic properties under in vitro conditions, can be used for starter culture development for the Cheka fermentation process.

Ameliorative effects of probiotic Limosilactobacillus fermentum and Enterococcus lactis isolated from cameroonian traditionally processed milk and palm wine against chronic constriction injury induced neuropathic pain in mice

Ethnopharmacological relevanceFermented milk and palm wine are regularly used by several ethnic groups in Cameroon in traditional treatment rituals for infections, inflammatory, cardiovascular disorders, and even metabolic diseases such as diabetes, hypercholesterolemia etc. Reports from many studies have demonstrated that fermented milk and palm wine are potential sources of probiotic bacteria. However, the capacity of probiotics isolated from these natural sources to alleviate neuropathic pain has not been experimentally tested. Aim of the studyThis study aimed at investigating the ameliorative potential of lactic acid bacteria isolated from palm wine and traditional fermented cow milk on the chronic constriction injury (CCI) induced neuropathic pain in mice. Materials and methodsPour plating technique on De Man Rogasa (MRS) agar was utilised for isolation of lactic acid bacteria from fermented cow milk and palm wine, and identified using the 16S r RNA gene sequencing. Neuropathic pain was induced by chronic constriction injury of the sciatic nerve. These bacteria were orally administered at different concentrations to Balb/c mice by gavage for 14 consecutive days. Cold allodynia, mechanical hyperalgesia and exploratory behaviour were evaluated on day 0, 7th and 14th respectively. The total level of calcium, oxidative stress markers and myeloperoxidase were also quantified in the sciatic nerve homogenate. Cyclooxygenase-2(COX-2) and cytokine profile were determined from serum. ResultsLactic acid bacteria were isolated from fermented cow milk and palm wine and two isolates were chosen according to their probiotic potentials and identified as strain of Limolactobacillus fermentum and Enterococcus lactis. Their 16 S rRNA gene sequences were deposited in NCBI genbank with accession number of OP896078 and OR619545, respectively. Pretreatment with Limosilactobacillus fermentum and Enterococcus lactis significantly alleviated mechanical hyperalgesia and cold allodynia with similar effect to the reference drug, morphine. These two isolates ameliorated CCI induced neuropathic pain by increasing antioxida776nts (GSH, CAT and SOD, P < 0.01) and decreasing pro-oxidants (MDA and NO, P < 0.01). Also, they inhibited the release of proinflammatory cytokines (IL-1β, TNF-α, IFN-γ, and IL-6; P < 0.01) and IL-10 level was significantly (P < 0.01) increased when compared to the negative control. Treatment with these bacteria significantly dropped the level of total calcium (P < 0.01), COX-2 (P < 0.01) and MPO (P < 0.01) when compared with the negative control. ConclusionThe neuroprotective potentials of these selected lactic acid bacteria against CCI induced neuropathic pain may be attributed to their anti-oxidant, anti-inflammatory properties and reduced calcium deposition in sciatic nerve.

Characterization of Probiotic Potential Lactic Acid Bacteria Isolated from Chinese Cabbage Brassica rapa subsp. Pekinensis

ABSTRACT This study aimed to isolate and evaluate the probiotic potential of lactic acid bacteria (LAB) from Chinese cabbage (Brassica rapa subsp. pekinensis) that is typically used in Kimchi, a Korean fermented product. Lactococcus lactis VLC.1 and VLC.2, and Lactococcus garvieae VLC.3 were identified and further assessed for their probiotic properties. These strains exhibited biological activity such as antioxidant capabilities, antimicrobial activity against pathogenic bacteria, hydrophobicity, and co-aggregation. These findings suggest their potential as probiotics to alleviate oxidative stress and maintain gastrointestinal flora balance. Significantly, the cell-free supernatants derived from LAB isolates exhibited synergistic antimicrobial activity with effectiveness against Escherichia coli, providing novel strategies to address antibiotic resistance challenges. The LAB isolates showed no antibiotic resistance and lacked hemolytic activity, underscoring their safety and efficacy as probiotics. In summary, our findings contribute valuable insights into the biological and safety properties of LAB strains isolated from Chinese cabbage, highlighting their functional benefits.

Unveiling the Potential of Lactic Acid Bacteria from Serbian Goat Cheese.

This study aimed to unleash the potential of indigenous lactic acid bacteria (LAB) originating from traditionally made Serbian goat cheese. Following the isolation and identification of the LAB, the safety aspects of the isolates were evaluated through tests for hemolytic activity and antibiotic sensitivity. The selected isolates were then tested for various technological properties, including growth in methylene blue, proteolytic activity, acidification, curd formation ability in both pure and enriched goat milk, diacetyl production, antagonistic potential against other LAB, and biofilm formation ability. The results indicated that Lactococcus spp., Lacticaseibacillus spp., and Lactiplantibacillus spp. did not exhibit α or β hemolysis, while enterococci displayed α hemolysis. A higher number of isolates demonstrated sensitivity to ampicillin, tetracycline, and streptomycin, while sensitivity to gentamicin and vancomycin was strain-dependent. Based on the evaluation of technological properties, Lacticaseibacillus paracasei M-1 and Lactiplantibacillus plantarum C7-7, C7-8, and C14-5 showed promising characteristics. Additionally, Lactococcus lactis subsp. lactis strains C0-14 and C21-8 emerged as promising candidates with notable technological properties. Notably, certain indigenous strains LAB exhibit promising technological properties and safety profiles. These characteristics make them suitable candidates for use as starter or adjunct cultures in goat's milk cheese production, potentially enhancing the quality and safety of the cheese as well as hygiene practices among small-scale dairy producers.

Modulating Whey Proteins Antigenicity with Lactobacillus delbrueckii subsp. bulgaricus DLPU F-36 Metabolites: Insights from Spectroscopic and Molecular Docking Studies.

Numerous studies have highlighted the potential of Lactic acid bacteria (LAB) fermentation of whey proteins for alleviating allergies. Nonetheless, the impact of LAB-derived metabolites on whey proteins antigenicity during fermentation remains uncertain. Our objective was to elucidate the impact of small molecular metabolites on the antigenicity of α-lactalbumin (α-LA) and β-lactoglobulin (β-LG). Through metabolomic analysis, we picked 13 bioactive small molecule metabolites from Lactobacillus delbrueckii subsp. bulgaricus DLPU F-36 for coincubation with α-LA and β-LG, respectively. The outcomes revealed that valine, arginine, benzoic acid, 2-keto butyric acid, and glutaric acid significantly diminished the sensitization potential of α-LA and β-LG, respectively. Moreover, chromatographic analyses unveiled the varying influence of small molecular metabolites on the structure of α-LA and β-LG, respectively. Notably, molecular docking underscored that the primary active sites of α-LA and β-LG involved in protein binding to IgE antibodies aligned with the interaction sites of small molecular metabolites. In essence, LAB-produced metabolites wield a substantial influence on the antigenic properties of whey proteins.

Probiotic potential of lactic acid bacteria isolated from yaks

The prevalence of bacterial digestive diseases in plateau animals has caused considerable losses to the Tibetan livestock industry. Therefore, this study aimed to isolate safe lactic acid bacteria (LAB) with beneficial probiotic properties to protect yaks from intestinal diseases. After 16S rDNA matching, four strains of Lactobacillus fermentum (A4), Pediococcus pentosaceus (A3.4 and A1.2), and Pediococcus acidilactici (B1.9) were isolated from the intestinal tissues and content of healthy yaks. The results indicated that A4 was more tolerant to bile salt (0.3%), while A3.4 had better stability in an acidic (pH = 3.0) environment. The results of the antibacterial activity test suggested that the isolates inhibited most pathogenic bacteria by up to 20%, except for A3.4, which inhibited Pasteurella and Staphylococcus aureus by more than 20%. Moreover, the results of the antioxidant test demonstrated that A4 and A3.4 had potent antioxidant activity. In addition, the drug sensitivity test revealed that the isolates were susceptible to commonly used antibiotics. In terms of safety, the isolates promoted growth, enhanced intestinal development, and protected the intestinal barrier without causing any adverse effects. In conclusion, LAB isolated from yak intestinal contents are potential probiotics with excellent antibacterial properties.

Harnessing the Health and Techno-Functional Potential of Lactic Acid Bacteria: A Comprehensive Review.

This review examines the techno-functional properties of lactic acid bacteria (LABs) in the food industry, focusing on their potential health benefits. We discuss current findings related to the techno-functionality of LAB, which includes acidification, proteolytic and lipolytic features, and a variety of other biochemical activities. These activities include the production of antimicrobial compounds and the synthesis of exopolysaccharides that improve food safety and consumer sensory experience. LABs are also known for their antioxidant abilities, which help reduce oxidative reactions in foods and improve their functional properties. In addition, LABs' role as probiotics is known for their promising effects on gut health, immune system modulation, cholesterol control, and general wellbeing. Despite these advantages, several challenges hinder the effective production and use of probiotic LABs, such as maintaining strain viability during storage and transport as well as ensuring their efficacy in the gastrointestinal tract. Our review identifies these critical barriers and suggests avenues for future research.

Antibacterial potential of lactic acid bacteria isolated from raw cow milk in Sylhet district, Bangladesh: A molecular approach.

The most prevalent probiotic bacterium employed in the food industry is Lactobacillus because it can produce metabolites with antibacterial capabilities and exhibits hostility towards infections and microorganisms that cause spoilage. This study set out to identify naturally occurring Lactobacillus and plantaricin (pln EF) coding genes in raw cow milk and to assess the antibacterial potency of isolated Lactobacillus isolates. Following enrichment in De Man, Rogosa and Sharpe (MRS) broth, single colonies were isolated, and pure colonies were obtained by streaking on MRS agar. The 16S rRNA gene was amplified using polymerase chain reaction (PCR) to confirm the cultural positivity of all isolates. Additionally, the presence of plantaricin was verified by targeting the pln EF gene through PCR. Out of the 166 raw milk specimens acquired from cows, 153 (91.17%; CI: 86.98-95.76) were identified as positive for Lactobacillus through both culture and biochemical screening. Subsequently, 121 (72.89%; CI: 65.46-79.49) of the isolates were affirmed to harbour Lactobacillus through PCR analysis. Within this subset, 6 isolates (4.96%; CI: 1.84-10.48) were found to possess the plnEF gene. When exposed to Lactobacillus isolates, Salmonella Typhimurium and Salmonella enterica displayed an average maximum zone of inhibition with a diameter measuring 24mm. In contrast, Escherichia coli exhibited an average minimum zone of inhibition, featuring a diameter of 11mm. Additionally, the Lactobacillus isolates demonstrated inhibitory zones against Staphylococcus aureus, Klebsiella pneumoniae and Klebsiella oxytoca, measuring 14, 22 and 19mm, respectively. Lactic acid bacteria, particularly Lactobacilli, are plentiful in cow milk and possess broad-spectrum antibacterial properties.

Characterization and potential lipid-lowering effects of lactic acid bacteria isolated from cats.

This study aimed to study the characterization and the potential lipid-lowering effects of new isolated lactic acid bacteria from the feces of healthy adult cats. We collected 85 cat fecal samples, isolated, screening lactic acid bacteria strains from samples, and investigated their in vitro and in vivo biological properties. A total of 221 lactic acid bacteria strains were isolated from 85 cat fecal samples. Sixteen strains with calcium dissolution rings greater than 1 mm were identified and selected for further characterization. Three lactic acid bacteria strains, Lactobacillus plantarum L-27-2, Pediococcus lactis L-14-1, and Enterococcus faecium, were identified as showing the most promising rates of cholesterol degradation (greater than 20%) and bacteriostatic radius (over 15 mm). These three strains exhibited robust growth and adherence to epithelial cells, along with adaptability to low pH (greater than 70%) and high bile salt conditions (greater than 60%), and remarkable cholesterol degradation and anti-pathogen activity. Sixteen mice were fed a high-fat diet (HFD) from 4 to 8 weeks of age, while a control group of the same size received a normal diet (ND). At 8 weeks of age, serum, feces and adipose tissue were collected. The results showed that, compared with mice fed an HFD diet alone, all mice fed an HFD diet plus lactic acid bacteria could decrease weight gain. P < 0.05 and the pathological changes of adipose tissue were alleviated. In addition, mice fed L-14-1 and F203 showed abdominal fat accumulation decreased (P < 0.05). Mice fed L-27-2 showed serum and liver triglyceride (TG) decreased (P < 0.05) and mice fed F203 showed serum high density lipoprotein cholesterol (HDL-C) increased (P < 0.01). mice fed L-27-2 and L-14-1 showed inflammatory cytokines (IL-6) was decreased (P < 0.01) Analysis of the fecal microbiota of mice fed these three lactic acid bacteria strains revealed alterations in the gut microbial community. There were common changes in intestinal microbes in mice fed these three lactic acid bacteria: (1) Bacteroides decreased; (2) Myxococcus increased; (3) Lachnoclostridium decreased. The microbes mentioned are all part of the core intestinal flora. This study provided three potential lactic acid bacteria for alleviating animal obesity and inflammation.

Isolation and Probiotic Characterization of Lactic Acid Bacteria from &amp;lt;i&amp;gt;Kindirmou&amp;lt;/i&amp;gt; and &amp;lt;i&amp;gt;Pendidam&amp;lt;/i&amp;gt; in Adamawa Region (Cameroon)

The microorganisms intended for use as probiotics in food formulation should exert health benefit effects and be regarded as safe for animals and humans uses. The aim of this study was to evaluate the probiotic potential of lactic acid bacteria (LAB) isolated from &amp;lt;i&amp;gt;pendidam&amp;lt;/i&amp;gt; and &amp;lt;i&amp;gt;kindirmou&amp;lt;/i&amp;gt;, two traditional fermented milks (TFM) produced in the Adamawa region (Cameroon). Twenty-five samples (&amp;lt;i&amp;gt;pendidam&amp;lt;/i&amp;gt;: 13 and &amp;lt;i&amp;gt;kindirmou&amp;lt;/i&amp;gt;: 12) were randomly collected in five markets of Ngaoundere (n = 17 samples) and Meiganga (n = 8 samples). These samples were screened for their antimicrobial activity, and nine TFMs were retained. Lactic acid bacteria were isolated from these samples and their antimicrobial activity was already evaluated. Based on the inhibition zone, twenty-two LABs were retained and examined &amp;lt;i&amp;gt;in vitro&amp;lt;/i&amp;gt; for potential probiotic properties based on their low pH tolerance, resistance to bile salts, tolerance to simulated gastrointestinal juices, hydrophobicity, autoaggregation, gelatinase and hemolytic activities. The outcome of these parameters studied was used as input data for a principal component analysis (PCA) to select the most promising isolate, and the six potential probiotic isolates were characterized through a biochemical profile. The characterized isolates have been identified as &amp;lt;i&amp;gt;Lactiplantibacillus plantarum, Lacticaseibacillus casei,&amp;lt;/i&amp;gt; and &amp;lt;i&amp;gt;Lactococcus lactis&amp;lt;/i&amp;gt;. Traditional fermented milks contain LAB with important properties that can be utilized in the formulation of functional foods.

Potential of Lactic Acid Bacteria Isolated from Fermented Foods for Yogurt Production and Antimicrobial Activity

Potential of Lactic Acid Bacteria Isolated from Fermented Foods for Yogurt Production and Antimicrobial Activity

PROBIOTIC PROPERTIES OF LACTIC ACID BACTERIA ISOLATED FROM MARE'S MILK

This work aims to identify and study the probiotic potential of lactic acid bacteria isolated from mare's milk. One of the main probiotic properties of the obtained strains is resistance to acidic pH media and bile acid salts, resistance to various types of antibiotics, adhesive ability and high antagonistic activity against pathogenic and opportunistic microorganisms. This article presents the study and isolation of lactic acid bacteria from mare's milk and presents the results of studying the biological properties of isolated strains and their identification. During the study, 98 isolates isolated from mare's milk samples were selected based on the biological properties of the strains. Some probiotic properties were determined using a total of 98 isolates, but the study continued with 41 strains. The most active strains that showed probiotic properties were selected from them, and the DNA model of the strains (deoxyribonucleic acid) was used in the genetic molecular diagnosis of microorganisms. When replicating the 16s gDNA zone, common bacterial primers for lactic acid bacteria were used. Based on 16s ribosomal gDNA analysis and carbohydrate profile, they were identified as Lactobacillus (L.) plantarum, L. Paracasei and L. casei.

Traditional Bulgarian Fermented Foods as a Source of Beneficial Lactic Acid Bacteria.

Traditional Bulgarian fermented foods are prominent for their uniqueness of local ingredients, production methods, and endemic microbial species. The present research investigated the diversity and beneficial biological potential of lactic acid bacteria (LAB) isolated from various types of unique Bulgarian fermented foods. Species identification was performed via 16S rDNA sequencing. Biological activity was evaluated by determining antibacterial activity (via agar well diffusion assay), H2O2 production, spectrophotometrically determined auto- and co-aggregation, microbial adhesion to hydrocarbon, and biofilm formation. The biosafety of the isolated lactic acid bacteria was established based on hemolytic activity and phenotypic and genotypic antibiotic susceptibility. Forty-five strains were isolated from fermented foods (sauerkraut, fermented green tomatoes, fermented cucumbers, kefir, white cheese, and Izvara (curdled milk)). Five species were detected: Lactiplantibacillus plantarum, Levilactobacillus koreensis, Levilactobacillus brevis, Lactobacillus helveticus, and Levilactobacillus yonginensis. The most prominent species was L. plantarum, at 47%. For the first time, L. koreensis and L. yonginensis, isolated from unique Bulgarian fermented foods, are reported in this study. The antibacterial effect of the cell-free supernatants was evaluated. An antagonistic effect was observed against Escherichia coli (57%) and Salmonella enterica subsp. enterica serotype Enteritidis (19%) for several L. plantarum strains. Only one L. brevis (Sauerkraut, S15) strain showed activity against E. coli. The best autoaggregation ability at hour 4 was observed for L. koreensis (fermented cucumbers, FC4) (48%) and L. brevis S2 (44%). The highest percentage of co-aggregation with Candida albicans, at hou 4 in the experiments, was observed for strains L. koreensis (fermented green tomato, FGT1) (70%), L. plantarum strains S2 (54%), S13 (51%), and S6 (50%), while at hour 24 for strains L. koreensis FGT1 (95%), L. brevis (Kefir, K7) (89%), L. plantarum S2 (72%), and L. koreensis FC2 (70%). Seven of the isolated LAB strains showed hydrophobicity above 40%. Our results showed that the ability of biofilm formation is strain-dependent. No hemolytic activity was detected. The antibiotic resistance to 10 antibiotics from different groups was tested phenotypically and genotypically. No amplification products were observed in any strains, confirming that the isolates did not carry antibiotic-resistance genes. Traditional fermented Bulgarian foods can be considered functional foods and beneficial LAB sources.

Viability of probiotic lactic acid bacteria in Malay apple (Syzygium malaccense) during fermentation and storage

For lactic acid bacteria (LAB) to be considered probiotic it must colonize and survive the gut environment, also for maximum health benefits it must be ingested in a sufficient amount. Hence, this study was aimed at investigating the probiotic potential of lactic acid bacteria and their viability in Malay apple juice. Five LAB of yoghurt origin were obtained and screened for probiotic potential using acidic pH (1.5) tolerance, bile salt (0.3 %) resistance and non-hemolytic activity as the selection and safety criteria. The compositional and physicochemical characteristics of the apple juice during fermentation were assayed using standard methods. The viable cell counts were determined using standard plate count method. Of the 5 LAB isolates 2 identified as members of Lactobacillus and Lactococcus genera showed good probiotic characteristics with acidic pH and bile salt survival rate of above 80 %, also the 2 LAB isolates were non-hemolytic. After the 72 h fermentation increase in protein content ranged from 0.53 to 1.21 %, titratable acidity increase ranged from 0.35 to 0.53 % and a reduction in pH ranged from 4.54 to 3.58 were obtained, also the viable cell counts were at 4.12±0.38, 2.35±0.15 and 3.18±0.10 CFU/ml in the Lactobacillus, Lactococcus and mixed culture fermented juice respectively. At the end of the 30 days cold (4oC) storage the viable cell counts were &gt;106 CFU/ml. The Lactobacillus fermented juice had more overall acceptability (7.7) by the panelists. In conclusion the studied LAB isolates were viable probiotics and Malay apple juice a suitable carrier for probiotics.

Application of Fermentation as a Strategy for the Transformation and Valorization of Vegetable Matrices

This review paper addresses vegetable fermentation from a microbiological and technological point of view, with particular emphasis on the potential of lactic acid bacteria to carry out these transformations. This review paper also covers the spectrum of traditional and emerging fermented plant foods. Fermentation with lactic acid bacteria represents an accessible and appropriate strategy to increase the daily consumption of legumes and vegetables. Often, lactic fermentation is carried out spontaneously following protocols firmly rooted in the culture and traditions of different countries worldwide. Fermented plant products are microbiologically safe, nutritious, and have pleasant sensory characteristics, and some of them can be stored for long periods without refrigeration. Controlled fermentation with selected lactic acid bacteria is a promising alternative to guarantee high-quality products from a nutritional and organoleptic point of view and with benefits for the consumer’s health. Recent advances in genomics and molecular microbial ecology predict a bright future for its application in plant fermentation. However, it is necessary to promote molecular approaches to study the microbiota composition, select starters aimed at different legumes and vegetables, generate products with nutritional properties superior to those currently available, and incorporate non-traditional vegetables.