Isolation and characterization of novel Lacticaseibacillus, Pediococcus, Enterococcus, Lentilactobacillus, and Levilactobacillus strains with probiotic potential from fermented turnip juice

Abstract

Lactic acid bacteria (LAB) isolates (29 isolates) from fermented turnip juices were identified using 16S rRNA gene sequencing techniques. The findings indicated that the most common strains belonged to Lacticaseibacillus sp. (55.17%), Pediococcus acidilactici (27.58%), and Enterococcus faecalis (6.89%). According to the results, all strains exhibited high resistance to low pH (2.0). Lacticaseibacillus sp. FS2 exhibited the greatest resistance (129.9 8%) to 1% bile salt, whereas Levilactobacillus brevis FL12 was the most sensitive (87.00%). However, all strains showed tolerance to pepsin (48.85–125.76%), pancreatin (56.14–169.01%), and phenol (54.16–113.24%) at various levels. The strains showed different levels of susceptibility to antibiotics. The antimicrobial activity of the strains against the test microorganisms exhibited considerable variability (8–30 mm). Although all strains showed viability at 1.5% NaCl, twelve strains survived at 10% NaCl. The proteolytic enzyme activity of the strains exhibited a range of 0.002 to 0.086 mg tyrosine/mL, whereas eight strains showed no β-galactosidase enzyme activity. Moreover, most of the strain showed high hydrophobicity towards xylene (16.39–94.43%), while auto-aggregation and co-aggregation abilities varied from 4.76 to 19.10% and 0.97 to 27.75%, respectively. In conclusion, the findings indicated that the strains exhibited high probiotic potential and could be employed as dietary supplements or as a starter culture for designing various functional food products.