Molecular identification of lactic acid bacteria associated with Chicha, a traditional maize-based fermented beverage from Northwestern Argentina

ELIZAQUÍVEL PATRICIA; ARISTIMUÑO FICOSECO MARIA CECILIA; COCCONCELLI, PIER SANDRO; VIGNOLO, GRACIELA M.; AZNAR ROSA

Estambul

Congreso; 15th European congress on Biotechnology; 2012

Federación Europea de Biotecnología y la Asociación de Biotecnología de Turquía

 Chicha is a traditionally homemade fermented alcoholicbeverage preparedfrom maize in the Andean highlands. Here the dominant lactic acid bacteria (LAB) species present during chicha production in NorthwesternArgentina were analyzed by molecular methods. Basically, chicha manufacturing involved a two-step fermentation process usingmaize flour as a substrate to which warm water was added. In a first step, manuallyshaped buns were cooked, grounded and mixed withmore maize flour, cane sugar, water and fermented (18-20º C for 7-8 days). Pre-fermentedmass was further added with fresh maize flour and water, this slurry being decanted(2-3 h) and three fractions were separated before the final fermentation (2-4days) was accomplished. Total microbial counts were in the range of 104-108cfu/g throughout the process with slight variations among assayed media. A total of 146 LAB isolatedfrom 10 samples from different manufacturing steps were identified by internalspacer region (ISR) and randomly amplified polymorphic DNA (RAPD) profiles asbelonging to the genera Leuconostoc(39%), Weissella (20%), Lactobacillus (23%) and Enteroccocus (18%). 16S rRNA genesequence and species-specific PCR revealed E. casseliflavus, Lb. plantarum, Leuc. mesenteroides, Leuc.lactis and W. viridescens as thepredominant species. Their distributionalong chicha production process showed the presence of E. casseliflavus in maize flour while bunsbefore cooking exhibited the highest diversity involving Lb. plantarum, W. viridescens,Leuc. mesenteroides and E. mundtii. From pre-fermented mass, Lb. plantarum and to a lesser extent Lb. brevis and Leuc. mesenteroides were identified, although W. viridescens was determined as the dominant species in the slurry.After decanting, top liquid-layer contained exclusively Leuc. lactis while the jelly-like sediment was dominated by Leuc. mesenteroides. Following concentration,both species but also Lb. plantarumwere recovered. Although RAPD profiles revealed intraspecies diversity, predominantLAB in the final fermented chicha werethermotolerant E. faecium (60%),probably of water origin, Leuc. lactis(27%) and Leuc. mesenteroides (13%) thatpersisted from the slurry fractions. Examination of these indigenous foods mayprovide information on unknown microbial genetic reservoirs which can be exploited as new functional starter cultures to improvenutritional and functional quality of traditional Andean foods.