RESUMEN
The microbial community of artisanal corn fermentation called Chicha were isolated, purified and then identified using protein profile by Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF) and confirmed by partial ribosomal gene sequencing. Samples from Chicha beverage were chemically characterized by gas and liquid chromatography (HPLC and GC-MS). Aerobic mesophilic bacteria (AMB) (35.8% of total of isolated microorganisms), lactic acid bacteria (LAB) (21.6%) and yeast (42.6%) were identified. Species of the genera Klebsiella, Bacillus, Staphylococcus, Micrococcus, Enterobacter, and Weissella were identified. Rhodotorula mucilaginosa, Lodderomyces elongisporus, Candida metapsilosis, and C. bohicensis were the yeasts found. The LAB isolates detected were responsible for the high concentrations of lactic acid found during the fermentation process (1.2 g L- 1), which is directly related to the decrease in pH values (from 6.95 to 3.70). Maltose was the main carbohydrate detected during corn fermentation (7.02 g L- 1 with 36 h of fermentation). Ethanol was found in low concentrations (average 0.181 g L- 1), making it possible to characterize the beverage as non-alcoholic. Twelve volatile compounds were identified by gas chromatography; belonging to the groups acids, alcohols aldehydes, acetate and others. MALDI-TOF was successfully used for identification of microbiota. Weissella confusa and W. cibaria were detected in the final product (after 36 h of fermentation), W. confusa is often classified as probiotic and deserve further application studies.