In vitro assessment of biofunctional properties of Lactiplantibacillus plantarum strain Jb21-11 and the characterization of its exopolysaccharide / Evaluación in vitro de las propiedades biofuncionales de Lactiplantibacillus plantarum cepa Jb21-11 y caracterización de su exopolisacárido

The microbiota of traditional food provides a rich reservoir of biodiversity to find new strains with interesting features for novel functional food formulation. Therefore, this study aimed to investigate the biofunctional potential of the lactic acid bacteria (LAB) strain Jb21-11 isolated from Jben, a traditional Algerian fresh cheese. This isolate was selected out of a collection of 154 LAB based on its exopolysaccharide (EPS) phenotype and was preliminarily identified by polyphasic characterization as Lactiplantibacillus plantarum (previously known as Lactobacillus plantarum) and its biofunctional properties were then assessed in vitro. The tested strain demonstrated good resistance to gastric juice, acidity around pH 2, and 2% (v/v) bile salts, which are important characteristics for potential biofunctional LAB candidates. It also showed a good production of ropy EPS with 674 mg/L on MRS medium. However, this ability appears to compromise the adhesion of the strain to Caco-2 cells (less than 1%), which according to our results, seems not to be related to autoaggregation and hydrophobicity (44.88 ± 0.028% and 16.59 ± 0.012%). Furthermore, promising antimicrobial activity against three pathogenic bacteria (Escherichia coli, Staphylococcus aureus, and Salmonella) was detected probably due to antimicrobial metabolites excreted during fermentation process into the medium. Moreover, the strain L. plantarum Jb21-11 displayed a therapeutic functionality with both anti-inflammatory and immunomodulatory action using RAW 264.7 cells. The chemical features of the novel ropy Jb21-11-EPS were also investigated revealing the presence of three monosaccharides, namely, mannose, galactose, and glucose, with a molar ratio of 5.42:1.00:4.52 linked together by α- and β-glycosidic bonds, presenting a relatively high molecular weight of 1.08 × 105 Da of interest for a texturing potential. Therefore, the new producing EPS strain Jb21-11 is a promising candidate for use as an adjunct culture for improving the texture of functional food.(AU)

In vitro assessment of biofunctional properties of Lactiplantibacillus plantarum strain Jb21-11 and the characterization of its exopolysaccharide.

ABSTACT: The microbiota of traditional food provides a rich reservoir of biodiversity to find new strains with interesting features for novel functional food formulation. Therefore, this study aimed to investigate the biofunctional potential of the lactic acid bacteria (LAB) strain Jb21-11 isolated from Jben, a traditional Algerian fresh cheese. This isolate was selected out of a collection of 154 LAB based on its exopolysaccharide (EPS) phenotype and was preliminarily identified by polyphasic characterization as Lactiplantibacillus plantarum (previously known as Lactobacillus plantarum) and its biofunctional properties were then assessed in vitro. The tested strain demonstrated good resistance to gastric juice, acidity around pH 2, and 2% (v/v) bile salts, which are important characteristics for potential biofunctional LAB candidates. It also showed a good production of ropy EPS with 674 mg/L on MRS medium. However, this ability appears to compromise the adhesion of the strain to Caco-2 cells (less than 1%), which according to our results, seems not to be related to autoaggregation and hydrophobicity (44.88 ± 0.028% and 16.59 ± 0.012%). Furthermore, promising antimicrobial activity against three pathogenic bacteria (Escherichia coli, Staphylococcus aureus, and Salmonella) was detected probably due to antimicrobial metabolites excreted during fermentation process into the medium. Moreover, the strain L. plantarum Jb21-11 displayed a therapeutic functionality with both anti-inflammatory and immunomodulatory action using RAW 264.7 cells. The chemical features of the novel ropy Jb21-11-EPS were also investigated revealing the presence of three monosaccharides, namely, mannose, galactose, and glucose, with a molar ratio of 5.42:1.00:4.52 linked together by α- and ß-glycosidic bonds, presenting a relatively high molecular weight of 1.08 × 105 Da of interest for a texturing potential. Therefore, the new producing EPS strain Jb21-11 is a promising candidate for use as an adjunct culture for improving the texture of functional food.

Characterization of Lactic Acid Bacteria Strains Isolated from Algerian Honeybee and Honey and Exploration of Their Potential Probiotic and Functional Features for Human Use.

Using culture enrichment methods, 100 strains of bacilli of lactic acid bacteria (LAB) were isolated from honeybee Apis mellifera intermissa and fresh honey, collected from apiaries located in the north-east of Algeria. Amongst all of the isolated LAB, 19 selected strains were closely affiliated to four species-Fructobacillus fructosus (10), Apilactobacillus kunkeei (5), Lactobacillus kimbladii and/or Lactobacillus kullabergensis (4)-using phylogenetic and phenotypic approaches. The in vitro probiotic characteristics (simulated gastrointestinal fluids tolerance, autoaggregation and hydrophobicity abilities, antimicrobial activity and cholesterol reduction) and safety properties (hemolytic activity, antibiotic resistance and absence of biogenic amines) were evaluated. The results indicated that some strains showed promising potential probiotic properties. In addition, neither hemolytic activity nor biogenic amines were produced. The carbohydrate fermentation test (API 50 CHL) revealed that the strains could efficiently use a broad range of carbohydrates; additionally, four strains belonging to Apilactobacillus kunkeei and Fructobacillus fructosus were found to be exopolysaccharides (EPS) producers. This study demonstrates the honeybee Apis mellifera intermissa and one of her products as a reservoir for novel LAB with potential probiotic features, suggesting suitability for promoting host health.