Evaluación de las actividades proteolítica, lipolítica, amilolítica, celulolítica, antagónica y resistencia microbiana de cepas bacterianas de interés biotecnológico

Abstract

The main objective of this research study was to evaluate the proteolytic, lipolytic, amylolytic, cellulolytic, antagonistic, and microbial resistance activities of bacterial strains of biotechnological interest, employing a non-experimental design study, with a cross-sectional analytical observational design. The study population was 23 pathogenic bacteria and 15 lactic acid bacteria. We proceeded in four stages: the purity of the bacteria was identified, tests were performed to identify the biological activities, the antagonistic activity of the lactic acid bacteria (LAB) was determined and microbial susceptibility was evaluated. As a result, gram- negative bacteria such as: Serratia marcescens, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella. pneumoniae, Escherichia coli, etc., were obtained. On the other hand, gram- positive bacteria such as Staphylococcus aureus, Staphylococcus saprophyticus, and lactic acid bacteria such as Lactococcus cremoris, and Lactococcus lactis subsp. lactis, Enterococcus faecium, and Lactococcus spp. Evaluating the biological activity, it was observed that 100% proteolytic activity, lipolytic 73.68%, amylolytic 89.47%, and cellulolytic 47.37%. In the analysis of the antagonistic activity of LAB, some species such as Lactococcus cremoris, and Lactococcus lactis subsp. lactis, Enterococcus faecium, and Lactococcus spp. inhibited Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus, and Staphylococcus saprophyticus, and an evident inhibition to Klebsiella pneumoniae was observed, in 75-93.33%. Finally, microbial susceptibility was evaluated, where enterobacteria were sensitive to gentamicin, and fosfomycin and resistant to various beta-lactams, micrococci were resistant to vancomycin and oxacillin, Staphylococcus saprophyticus were resistant to all antibiotics used and LAB was sensitive to chloramphenicol, erythromycin, and ampicillin. It was concluded that enterobacteria, micrococcus, and LAB showed biological activity, LAB showed a high percentage of inhibition to pathogens, and bacterial resistance to several antibiotics was verified. It is recommended to take advantage of the biological activity of the analyzed bacteria to use them in the food, textile, paper, disinfectant, etc. industries.