Ethnobiotechnological Analysis of the Lactic Bacterial Diversity in the Mezcal Fermentation of Four Palenques in Oaxaca, Mexico

Mezcal is an ancestral beverage from Oaxaca, Mexico, produced using traditional biotechnological procedures without artificial inoculation. The role of bacteria in fermentation has been studied less. Our work aimed to analyze the bacterial diversity in mezcal must and determine its relationship with ethnobiotechnological variables. Fermentation must samples were collected from four Palenques in the Valles Centrales, Cañada, and Mixteca regions of Oaxaca. Molecular and phenotypic identification and characterization, including ethanol tolerance testing, were performed. Ethnobiotechnological data were acquired through interviews and official databases. Six bacterial genera were identified in mezcal must, including Lactiplantibacillus, Enterobacter, Enterococcus, Bacillus, Leuconostoc, and Levilactobacillus. Therefore, through a factorial experiment, it was determined that the selected Lactiplantibacillus plantarum strains were able to withstand 6% and 8% ethanol. A direct relationship was observed between species diversity and the degree of population marginalization. Palenque 2, representing the most urbanized population, exhibited the lowest diversity, with only two species detected. In contrast, Palenques characterized by high marginalization harbored a substantially greater diversity, ranging from six to ten species. These differences are likely associated with variations in microbiota composition, microbial growth dynamics, and ethanol tolerance. Overall, the findings suggest that ethnobiotechnological factors play a significant role in shaping bacterial diversity. In Oaxaca, “ethnobiotechnological” implies the deep relationship between biodiversity, Indigenous culture, and territory, with a strong emphasis on living traditional knowledge and its intergenerational transmission.