Abstract

Probiotics have been used in the clinical field for their antimicrobial activity and immunomodulatory effect, spore probiotics from genus Bacillus have become relevant as dietary supplements due to their ability to survive passage through the gastrointestinal tract, limiting studies of the probiotic capacity of vegetative cells. In this study we analyzed the biomass and polysaccharides production of B. clausii and the probiotic potential of its vegetative cells. The bacterium was cultured in Brain-Heart Infusion broth (BHI), Müeller-Hinton (MH) and Sabouraud Dextrose (SD), quantifying the biomass and polysaccharides produced in each medium, the probiotic potential of the cells was evaluated through their antagonistic activity and resistance to gastric acids. The medium that produced the highest amount of biomass (5,6967 ± 0.0695 g/L) and intrapolysaccharides (0.2965 ± 0.0445 g/L) was MH, while BHI obtained the highest value of exopolysaccharides (14,250 ± 0.212 g/L). Although no solid antimicrobial activity was obtained, the supernatant had antagonistic activity against Listeria monocytogenes (27.37 ± 17.38%), Escherichia coli (19.09 ± 15.89%) and Enterococcus faecalis (15.63 ± 8.54%). Low pH levels significantly affect the viability of B. clausii vegetative cells at 24 and 48 h, however, exposure times do not appear to influence the inhibition percentage. Future studies in this line are required to deeply determine its probiotic potential, applying possible strategies such as microencapsulation and media supplementation.