Growth ability, microbial activity and susceptibility to antimicrobials of two strains of Pediococcus pentosaceus, candidates to probiotic

Resumen

The objective of this study was to evaluate growth ability, antimicrobial activity and susceptibility to antimicrobials of two strains of Pediococcus pentosaceus (LB-12 and LB-25), candidates to probiotic. Four trials were performed with randomized designs and three repetitions. Strain growth in a MRS medium at 37 ºC had a similar performance, and from 6h of culture, they reached the stationary stage. Their growth speeds were around 0.5 h-1 and duplication times were 1.3 h. Both were able to grow and decrease pH of a medium were fructans of Agave fourcroydes were used as energy source, although its concentration decreased regarding the MRS medium. In addition, strains inhibited the growth of evaluated pathogenic bacteria, with a high antimicrobial action of LB-25 against Salmonella enterica subsp. enterica serovar Typhimurium ATCC 14028 and Listeria monocytogenes ATCC 1531. Candidates to probiotic were sensitive to G penicillin, florfenicol, chloramphenicol, amoxicillin clavulanic acid and doxycycline. At the same time, were resistant to trimethoprine-sulfamethoxazole, cephalexin, tetracycline, vancomycin, nalidixic acid, oxalinic acid, enrofloxacin and flumequine, streptomycin, kanamycin and gentamicin. It can be concluded that P. pentosaceus LB-12 and LB-25, in vitro, have an antimicrobial activity against pathogens, are susceptible to antimicrobials and have a proper growth ability in a MRS medium, and when fructans are used as energy source, which favors their inclusion in symbiotic and probiotic formulations for animal production.