Bioprospecção e avaliação do potencial probiótico de bactérias ácido láticas isoladas de produto fermentado artesanalmente

Abstract

The consumption of probiotic and fermented products has been highlighted as an alternative for improving health, covering a number of parameters of the functioning of the immune, gastric, and neural systems. It is used both as a prevention of physical and mental illnesses, and as a curative measure for them. These products use lactic acid bacteria as fundamental microorganisms for fermentation, which produce, through various mechanisms of action, a variety of bioactive compounds and other substances with beneficial effects on health, many of which are still unknown. This study aimed to perform the bioprospecting of lactic acid bacteria isolated from milk kefir, a handmade fermented product, in order to evaluate their probiotic potential through proof of their identification (morphology), their safety (research of pathogenicity factors and resistance to antimicrobials) and their beneficial effects (antagonistic activity against pathogens and production of exopolysaccharides). The results obtained indicated that from the 11 isolated strains, only three showed sensitivity to gentamicin and amoxicillin, while the others showed resistance to phosphomycin, norfloxacin and ciprofloxacin, besides the other antibiotics previously mentioned. Regarding pathogenicity, one of the strains showed high ability to destroy red blood cells, showing its pathogenic potential. On the other hand, only strains MK3, MK10 and MK11 showed no hemolytic activity, suggesting a lower pathogenicity potential and a possible probiotic profile. However, their practical application is challenging, due to their prolonged growth rate, and the work with these strains proved to be unfeasible. Although relevant information on the absence of pathogenicity and antimicrobial activity of the strains studied was obtained, the lack of conclusive results on antagonistic activity represents a significant limitation of this study. In this sense, further investigations are necessary to elucidate the best way to grow these microorganisms and evaluate the probiotic potential of these strains regarding their ability to inhibit pathogen growth.