Characterization and in vitro properties of Lactobacillus plantarum and Leuconostoc mesenteroides for probiotic potential and nitrite degradation

Abstract

In the present work, the nitrite degradation activity and probiotic potential of heterofermentative Leuconostoc mesenteroides (LM) and homofermentative Lactobacillus plantarum (LP) were demonstrated. The potential probiotic properties of these bacteria were determined in vitro based on their antimicrobial activity, antibiotic resistance, aggregation properties, hydrophobicity, survival under simulated gastrointestinal tract conditions, and hemolytic activity. The results suggested that these two lactic acid bacteria (LAB) species possess hydrophobicity as they exhibited microbial adhesion to xylene, chloroform, and ethyl acetate. The two strains also showed general resistance to simulated gastric and intestinal conditions. The LM was resistant to erythromycin, chloramphenicol, norfloxacin, and vancomycin, while the LP showed resistance to clindamycin, tetracycline, erythromycin, norfloxacin, and vancomycin. Both LAB were efficient antimicrobials toward Escherichia coli and Staphylococcus aureus based on their inhibition zones. Furthermore, these LAB showed good tolerance toward nitrite, and displayed α- and γ-hemolysis. These results suggest that LM and LP are promising probiotic candidates.