Isolation of bacteria with probiotic potential from pulque

Abstract

Objective: Starting pulque, isolate bacteria with probiotic potential for animal nutrition.

Design/methodology/approach: 500 mL of pulque were sampled and collected from the municipalities: Tlatlauquitepec, Puebla; Otumba and Tequexquinahuac, State of Mexico. To samples the pH, humidity, ash, protein were determined and morphologically, the bacterial colonies were isolated and identified. Also, the colony strains that underwent Gram staining and the catalase test were preselected. Finally, the bacterial strains with probiotic potential, resistance to pH, bile salts and antimicrobial activity were selected.

Results: From the pulque samples by municipality, a pH, humidity, ash and protein were obtained from Tlatlauquitepec (3.3, 96.17 %, 5.98 % and 0.352 g/100 mL^-1), Otumba (3.25, 97.67 % and 0.1763 g/100 mL^-1) and Tequexquinahuac (2.25, 97.55 %, 4.65 % and 0.1765 g/100 mL^-1). Likewise, 6 different strains were isolated: C2, C3 and C4; Tequexquinahuac, C5 and C6; Otumba and C1; Tlatlauquitepec. On the other hand, it was found that the C1 strain was able to grow at a pH of 3.0 with survival of 84 % and 73 % in bile salts. Finally, the C1 strain did not show antimicrobial activity against the pathogenic bacteria Escherichia coli (E. coli) ATCC 25922 and Salmonella typhimutium ATCC 14028.

Study limitations/implications: Pulque bacterias have probiotic characteristics that can be used for animal feed.

Findings/conclusions: It was found that the C1 strain grew at a pH of 3.0 and showed a high survival percentage, which can be used as a probiotic in animal feed.