Safety and probiotic functionality of isolated goat milk lactic acid bacteria

Probiotic Properties and Safety Evaluation in the Invertebrate Model Host Galleria mellonella of the Pichia kudriavzevii YGM091 Strain Isolated from Fermented Goat Milk

Potential probiotic yeast strains isolated from fermented food need to meet safe and beneficial conditions for the host's health. The Pichia kudriavzevii YGM091 strain isolated from fermented goat milk has outstanding probiotic characteristics, including: the high survival percentage in digestive system conditions (reaching up 247.13 ± 0.12 and 145.03 ± 0.06% at pH 3.0 and bile salt 0.5%, respectively); good tolerance to temperature, salt, phenol, ethanol; good surface properties such as high hydrophobicity percentage (> 60%), the high auto-aggregation percentage rate (66.56 ± 1.45% after 45 min of incubation) and the high co-aggregation percentage rate with pathogenic bacteria in a short time (> 40% after 2 h of incubation); biofilm forming after 24 h of incubation on abiotic surfaces; antioxidant activity reached excellent level after only 24 h of incubation (The percentage free radical scavenging and the Trolox equivalent reaching up 79.86 ± 0.70% and 92.09 ± 0.75 µg/mL after 72 h of incubation); extracellular enzymes production protease and cellulase with high activity, amylase and pectinase with moderate activity and non-lipase activity. Simultaneously, the YGM091 strain is the in vitro safety yeast: insensitive to antibiotics and fluconazole, negative for gelatinase, phospholipase, coagulase, and non-hemolysis activities. Furthermore, this strain is in vivo safety yeast with the dosages below 106 CFU/larva in the Galleria mellonella model with over 90% survival larvae and the yeast density reduced to just 102-103 CFU/larva after 72 h post-injection. Research results have demonstrated that the Pichia kudriavzevii YGM091 strain is a safe potential probiotic yeast and could become a candidate probiotic food to be used in the future.

Selection of starter lactic acid bacteria capable of forming biofilms on wooden vat prototypes for their future application in traditional Sicilian goat's milk cheese making

In this study, 327 presumptive lactic acid bacteria (LAB) were isolated from goats' milk acid curds produced at a Sicilian dairy farm with the aim to identify potential starter cultures for traditional cheeses. All isolates were first processed by randomly amplified polymorphic DNA (RAPD)-PCR analysis. This approach identified 63 distinct strains which were evaluated for their acidifying capacity. Only 15 strains specifically stood out for their acidification capacity and were identified through 16S rRNA gene sequencing as Lactococcus lactis (11 strains) Enterococcus faecalis (three strains), and Ligilactobacillus animalis (one strain). Notably, all 15 LAB isolates produced bacteriocin-like inhibitory substances and anti-biofilm compounds, against both planktonic and biofilm forms of Listeria monocytogenes, Salmonella Enteritidis, Escherichia coli, and Staphylococcus aureus, albeit at varying levels. Among these 15 LAB, En. faecalis RGM25 and Lc. lactis RGM55, susceptible to five antibiotics tested, were put in contact with wooden vat prototypes, because all equipment used in traditional cheese production in Sicily are made of wood. Scanning electron microscopy and bacterial plate counts of the wooden vat prototypes showed the development of biofilms at levels of approximately 6.0 log CFU/cm2. Overall, this study contributes to establishing a custom-made LAB starter cultures with bio-preservatives properties for Sicilian cheese productions.

Harnessing the probiotic properties and immunomodulatory effects of fermented food-derived Limosilactobacillus fermentum strains: implications for environmental enteropathy

Introduction

Environmental enteropathy (EE), a chronic small intestine disease characterized by gut inflammation, is widely prevalent in low-income countries and is hypothesized to be caused by continuous exposure to fecal contamination. Targeted nutritional interventions using potential probiotic strains from fermented foods can be an effective strategy to inhibit enteric pathogens and prevent chronic gut inflammation.

Methods

We isolated potential strains from fermented rice water and lemon pickle and investigated their cell surface properties, antagonistic properties, adhesion to HT-29 cells, and inhibition of pathogen adherence to HT-29 cells. Bacteriocin-like inhibitory substances (BLIS) were purified, and in vivo, survival studies in Caenorhabditis elegans infected with Salmonella enterica MW116733 were performed. We further checked the expression pattern of pro and anti-inflammatory cytokines (IL-6, IL8, and IL-10) in HT-29 cells supplemented with strains.

Results

The strains isolated from rice water (RS) and lemon pickle (T1) were identified as Limosilactobacillus fermentum MN410703 and MN410702, respectively. Strains showed probiotic properties like tolerance to low pH (pH 3.0), bile salts up to 0.5%, simulated gastric juice at low pH, and binding to extracellular matrix molecules. Auto-aggregation of T1 was in the range of 85% and significantly co-aggregated with Klebsiella pneumoniae, S. enterica, and Escherichia coli at 48, 79, and 65%, respectively. Both strains had a higher binding affinity to gelatin and heparin compared to Bacillus clausii. Susceptibility to most aminoglycoside, cephalosporin, and macrolide classes of antibiotics was also observed. RS showed BLIS activity against K. pneumoniae, S. aureus, and S. enterica at 60, 48, and 30%, respectively, and the protective effects of BLIS from RS in the C. elegans infection model demonstrated a 70% survival rate of the worms infected with S. enterica. RS and T1 demonstrated binding efficiency to HT-29 cell lines in the 38-46% range, and both strains inhibited the adhesion of E. coli MDR and S. enterica. Upregulation of IL-6 and IL-10 and the downregulation of IL-8 were observed when HT-29 cells were treated with RS, indicating the immunomodulatory effects of the strain.

Discussion

The potential strains identified could effectively inhibit enteric pathogens and prevent environmental enteropathy.

Alpha-amylase and alphaglucosidase inhibitory properties, beta-galactosidase activity, and probiotic potential of lactic acid bacteria and bifidobacteria from Apis mellifera intermissa and its products

The present study aimed to evaluate the probiotic potential, α-amylase and α-glucosidase inhibitory effects, and β-galactosidase production of 19 non haemolytic lactic acid bacteria and bifidobacteria previously identified and isolated from honey bee gastrointestinal tract (BGIT) of Apis mellifera intermissa, honey, propolis and bee bread. The isolates were screened according to their high resistance to lysozyme and potent antibacterial activity. Our results indicated that among the 19 isolates, Limosilactobacillus fermentum BGIT_E12.2, Lactiplantibacillus plantarum BGIT_EC13, Limosilactobacillus fermentum BGIT_EC5.1 and Bifidobacterium asteroides BGIT_OB8, isolated from BGIT exhibited a good tolerance to 100 mg/mL lysozyme (> 82%), excellent tolerance to 0.5% bile salt [survival rate (SR) ≥ 83.19% ± 0.01], and a high SR (≥ 80.0%) under gastrointestinal tract conditions. The auto-aggregation ability was high (auto-aggregation index ranging from 67.14 ± 0.16 to 92.8% ± 0.03) for L. fermentum BGIT_E12.2, L. plantarum BGIT_EC13, and B. asteroides BGIT_OB8, and moderate for L. fermentum BGIT_EC5.1 (39.08% ± 0.11). Overall, the four isolates showed moderate co-aggregation capacity with pathogenic bacteria. They exhibited from moderate to high hydrophobicity towards toluene and xylene. The safety assessment revealed that the four isolates lacked gelatinase and mucinolytic activities. Also, they were susceptible to ampicillin, clindamycin, erythromycin, and chloramphenicol. Interestingly, the four isolates showed α-glucosidase and α-amylase inhibitory activities ranging from 37.08 ± 0.12 to 57.57% ± 0.1 and from 68.30 ± 0.09 to 79.42% ± 0.09, respectively. Moreover, L. fermentum BGIT_E12.2, L. plantarum BGIT_EC13, L. fermentum BGIT_EC5.1 isolates exhibited β-galactosidase activity over a wide range of 52.49 ± 0.24-746.54 ± 0.25 Miller Units. In conclusion, our findings suggest that the four isolates could be potential candidates for probiotics with interesting functional properties.

Characterization of autochthonous lactobacilli from goat dairy products with probiotic potential for metabolic diseases

The present study aimed to design functional fermented goat milk with probiotic potential for metabolic diseases. Thereby, autochthonous lactobacilli from goat dairy products that target improving the inflammatory, lipid, and glycemic profile were characterized. We designed fermented goat milk using Lactobacillus delbrueckii subsp. indicus CRL1447 as starter strain, supplemented with different probiotic consortia formed by Limosilactobacillus fermentum CRL1446, Lactiplantibacillus paraplantarum CRL1449, and CRL1472 strains. These lactobacilli were selected for their positive effects on inhibition of α-glucosidase, bile salts hydrolase activity, cholesterol assimilation, and decreased triglyceride percentage in Caenorhabditis elegans. Furthermore, the lactobacilli oral administration to obese mice caused a significant decrease in body weight gain and ameliorated hyperglycemia and hyperlipemia. These results reveal the potential of this goat dairy product as a functional food to prevent obesity and related pathologies. Goat milk-derived products stand out for their marketing potential. Hence, fermented goat milk incorporating novel probiotics represents a group of food products with broad prospects by their promising nutritive and therapeutic properties for metabolic diseases. The goat dairy product designed in this study could be used in the prevention of dyslipidemia and hyperglycemia in obese people.

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New probiotic consortium (CRL1449, CRL1472, and ​CRL1446) was selected.

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The probiotic consortium showed in vitro immuno and adipomodulatory properties.

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Lactobacillus delbrueckii subsp. indicus CRL1447 was selected as a starter culture for fermented milk elaboration.

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Manufacturing of a functional fermented goat milk with a new probiotic consortium.

Incidence of virulence determinants and antibiotic resistance in lactic acid bacteria isolated from food products

Background: Lactic acid bacteria (LAB) confer beneficial health effects in humans. However, the safety of these bacteria and their potential to spread resistance in the environment must be evaluated. Materials & methods: Fifty-three LAB were isolated from different food samples and assessed for the prevalence of virulence determinants and antibiotic resistance profile. Results: Multiple resistance was reported for Lactobacillus brevis MIM04, having revealed phenotypic resistance to vancomycin (MIC >128 μg/ml), ampicillin, cefotaxime, oxacillin and gentamicin. Virulence traits (cylA, gelE, esp and agg) were detected using specific primers. Enterococcus faecium CHE32, Lactobacillus plantarum CHE37 and E. faecium MLK68 lack virulence genes, possess antimicrobial activity and survive in low pH and bile salt conditions. Conclusion: Isolated LAB revealed probiotic properties.

Probiotic potential of Weissella paramesenteroides MYPS5.1 isolated from customary dairy products and its therapeutic application

Probiotics are viable microorganisms that confer general health benefits to the host when consumed in an adequate concentration. Probiotics may also possess strain-specific therapeutic properties and therefore finding novel strains with probiotic properties is becoming increasingly important. The present study has focused on the isolation of probiotic bacteria from dairy products which possessed potential therapeutic properties. Of the 79 strains isolated, eight were selected for further studies based on a number of traits including biofilm formation, deoxyribonuclease (DNase) activity, agglutination activity, auto-aggregation activity, antibiotic resistance, and antagonistic activity. Strain MYPS5.1 was selected from the eight isolates as the best potential probiotic candidate strain and was subsequently identified as Weissella paramesenteroides by 16S rDNA gene sequencing and sequence analysis. W. paramesenteroides strain MYPS5.1 was resistant to a number of antibiotics and the strain produced a high concentration of exopolysaccharide (EPS) (380.42 mg/L). The functional groups C-H, C = C, N = N, N-H, and C-O in the EPS were identified by using Fourier transform infrared (FTIR) spectroscopy. Computational studies showed that it interacted with cyclin-dependent kinase (CDK), a molecule which is thought to play a role in cancer pathogenesis (REF). Collectively, these results suggest that Weissella paramesenteroides MYPS5.1 is a potential probiotic strain with potential therapeutic properties.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-03074-2.

Exopolysaccharides Producing Lactic Acid Bacteria in Wine and Other Fermented Beverages: For Better or for Worse?

Lactic acid bacteria (LAB) from fermented beverages such as wine, cider and beer produce a wide range of exopolysaccharides (EPS) through multiple biosynthetic pathways. These extracellular polysaccharides constitute key elements for bacterial species adaptation to such anthropic processes. In the food industry, LAB polysaccharides have been widely studied for their rheological, functional and nutritional properties; however, these have been poorly studied in wine, beer and cider until recently. In this review, we have gathered the information available on these specific polysaccharide structure and, biosynthetic pathways, as well as the physiology of their production. The genes associated with EPS synthesis are also presented and compared. Finally, the possible role of EPS for bacterial survival and spread, as well as the risks or possible benefits for the winemaker and the wine lover, are discussed.

Bioprospecting of Palmyra Palm (Borassus flabellifer) Nectar: Unveiling the Probiotic and Therapeutic Potential of the Traditional Rural Drink

The present study investigates the therapeutic and probiotic attributes of traditional Toddy Palm Nectar (TPN). Glucose was found to be the highest with 4.37 mg/ml and arabinose was the least with 2.85 mg/ml. The average ethanol concentration of fresh TPN was found to be 0.3 mg/ml. The nutritional profile of TPN revealed 18 volatile fatty acids, the major one being hexadecenoic acid (M/Z 74). Amino acid profiling showed 26 amino acids, with OH-lysine-2 the highest (12.86%). About 120 morphologically distinct lactic acid bacteria (LAB) were isolated from 26 TPN samples, based on differential growth and in vitro probiotic characteristics. After 16S rRNA sequencing, four indigenous LAB strains were identified as Lactobacillus plantarum group OUBN1, Enterococcus faecium OUBN3, Pediococcus acidilactici OUBN4, and Pediococcus pentosaceous OUBN5 and their sequences were deposited to NCBI. Microbiological safety evaluation studies showed the absence of hemolytic, gelatinolytic and proteolytic activity. The bacterial isolate OUBN3 showed a maximum survival rate of 6.91 ± 0.04 log cfu/ml at acidic pH 2.5 and isolate OUBN5 showed 6.94 ± 0.02 log cfu/ml at pH 3.0. Similarly, the isolate OUBN5 showed 7.92 ± 0.03 log cfu/ml to 0.3% ox-bile after 4 h and 8.94 ± 0.03 log cfu/ml to simulated gastric juice after 3 h of treatments. OUBN1 expressed the highest autoaggregation (81.76 ± 1.25%), cell surface hydrophobicity (79.71 ± 3.42%), and displayed the maximum coaggregation with E. coli MTCC452 (76.96%), K. pneumoniae MTCC109 (75.62%), and S. aureus MTCC902 (70.69%). All strains showed significant antibiotic and antimicrobial activity. Isolate OUBN1 displayed hydroxyl radical scavenging activity (68.71 ± 1.0%) with an IC50 value of 75.62 μg/ml and the highest anti-cancer activity (percentage inhibition of 88.55) against HT-29 cells. Based on the characteristics observed, L. plantarum group OUBN1 and P. pentosaceous OUBN5 were found to be potential isolates to employ as probiotic microbiota in food and forage preparations. These findings reinforce the fact that LAB isolated from TPN could be exploited as an alternative means toward potential therapeutic applications.

Probiotics in the dairy industry-Advances and opportunities

The past two decades have witnessed a global surge in the application of probiotics as functional ingredients in food, animal feed, and pharmaceutical products. Among food industries, the dairy industry is the largest sector where probiotics are employed in a number of dairy products including sour/fermented milk, yogurt, cheese, butter/cream, ice cream, and infant formula. These probiotics are either used as starter culture alone or in combination with traditional starters, or incorporated into dairy products following fermentation, where their presence imparts many functional characteristics to the product (for instance, improved aroma, taste, and textural characteristics), in addition to conferring many health-promoting properties. However, there are still many challenges related to the stability and functionality of probiotics in dairy products. This review highlights the advances, opportunities, and challenges of application of probiotics in dairy industries. Benefits imparted by probiotics to dairy products including their role in physicochemical characteristics and nutritional properties (clinical and functional perspective) are also discussed. We transcend the traditional concept of the application of probiotics in dairy products and discuss paraprobiotics and postbiotics as a newly emerged concept in the field of probiotics in a particular relation to the dairy industry. Some potential applications of paraprobiotics and postbiotics in dairy products as functional ingredients for the development of functional dairy products with health-promoting properties are briefly elucidated.

Screening of Lactobacillus plantarum Subsp. plantarum with Potential Probiotic Activities for Inhibiting ETEC K88 in Weaned Piglets

For screening excellent lactic acid bacteria (LAB) strains to inhibit enterotoxigenic Escherichia coli (ETEC) K88, inhibitory activities of more than 1100 LAB strains isolated from different materials, and kept in the lab, were evaluated in this study. Nine strains with inhibition zones, at least 22.00 mm (including that of a hole puncher, 10.00 mm), and good physiological and biochemical characteristics identified by 16S DNA gene sequencing and recA gene multiple detection, were assigned to Lactobacillus (L.) plantarum subsp. plantarum (5), L. fermentum (1), L. reuteri (1), Weissella cibaria (1) and Enterococcus faecalis (1), respectively. As investigated for their tolerance abilities and safety, only strain ZA3 possessed high hydrophobicity and auto-aggregation abilities, had high survival rate in low pH, bile salt environment, and gastrointestinal (GI) fluids, was sensitive to ampicillin, and resistant to norfloxacin and amikacin, without hemolytic activity, and did not carry antibiotic resistance genes, but exhibited broad spectrum activity against a wide range of microorganisms. Antibacterial substance may attribute to organic acids, especially lactic acid and acetic acid. The results indicated that the selected strain L. plantarum subsp. plantarum ZA3 could be considered a potential probiotic to inhibit ETEC K88 in weaned piglets for further research.