Preliminary probiotic potential of selected aerococcus spp., enterococcus spp., and weisella sp. from algerian guedid

Methods: Antimicrobial activity, acidity, growth Kinetics, quantification, heat and enzymes sensitivities were assayed against Listeria ivanovii CECT148, Bacillus cereus ATCC11778, Staphylococcus aureus ATCC25923 and Clostridium perfringens CECT486. Assessment of proteolysis, lipolysis, amylolysis, gelatinase, bile salts hydrolase, acetoin and exopolysaccharides production, acidity conditions, bile salts, gastric and intestinal resistances were determined. Survival lactic acid bacteria was then calculated using single plate-serial dilution spotting. Cholesterol assimilation, hemolysis and antibiotic resistance were also characterized. Statistical analysis was performed using originPro v9.5.

Results: The neutralized supernatants of Aerococcus spp. (Lbm19, 18, 3) and Enterococcus sp. (Lbm49, 46, 50) showed 9 mm inhibition zone, Clostridium. perfringens CECT486 was the most sensitive one. Lactic acid bacteria decreased by 1-2 log CFU/mL on gastrointestinal conditions and assimilated cholesterol by up to 89%. The antagonistic peak was obtained at the stationary phase where pH 3.5 was reached. The supernatant was sensitive to enzymes and heat. All candidates showed digesting ability for proteins but not for starch, lipids, gelatin, bile salts, also showed no hemolytic activity. All candidates were found to resist against two antibiotics and three isolates exhibited negative for exopolysaccharides and acetoin production.

Conclusion: Enterococcus sp.Lbm49, Aerococcus sp.Lbm19, Aerococcus sp.Lbm18, Enterococcus sp.Lbm46, and Aerococcus sp.Lbm3 showed the highest potential probiotic score. This study should be completed by a molecular characterization, ex vivo and in vivo tests.