Introduction:

Artisanal cheese produced from unpasteurized milk can harbor pathogens microorgaisms that can pose serious health risks of the consumers. However, wild starter cultures from artisanal cheeses can enhance the flavor of cheeses made from pasteurized milk. The aim of this work was to study the population dynamics for isolate lactic acid bacteria (LAB) from cheese whey fermented strand (CWFS).

Method:

Cheese whey was obtained from the traditional process for making string cheese using unpasteurized milk (Tuxtepec, Oaxaca, Mexico). For 120 h, aliquots of CWFS were obtained at different times; they were used to determine the pH of the medium and inoculating selective media plates of MRS, M17, and Elliker APT. The isolates were characterized morphologically, biochemically and molecularly.

Results:

The population of LAB was modified as a function of time and pH of the medium value (4.05 to 3.4). Twenty-two catalase negative and Gram-positive strains were isolated. Phylogenetic analysis (16S rDNA) indicated the presence of four strains of Enterococcus (VD, VH, VL, VB) and one of Lactobacillus (VK). The VH strain predominated over the other strains and together strain VK remained throughout the bioprocess.

Discussion or Conclusion:

The modification of pH of CWFS allowed to isolate LAB strains, they could be used as starter cultures for cheese production according to the specifications of the NOM-243-SSA1-2010 without compromising their sensory quality.