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

ELIZAQUIVEL, PATRICIA; ARISTIMUÑO, CECILIA; COCCONCELLI, PIER SANDRO; VIGNOLO, GRACIELA; AZNAR, ROSA

Istambul

Simposio; FoodMicro 2012. 23rd. International ICFMH Symposium; 2012

ICFMH

Chicha is a traditionally homemade fermented alcoholic beverage prepared from maize in the Andean highlands. Here the dominant lactic acid bacteria (LAB) species present during chicha production in Northwestern Argentina were analyzed by molecular methods. Basically, chicha manufacturing involved a two-step fermentation process using maize flour as a substrate to which warm water was added. In a first step, manually shaped buns were cooked, grounded and mixed with more maize flour, cane sugar, water and fermented (18-20º C for 7-8 days). Pre-fermented mass 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 (2-4 days) was accomplished. Total microbial counts were in the range of 104-108 cfu/g throughout the process with slight variations among assayed media. A total of 146 LAB isolated from 10 samples from different manufacturing steps were identified by internal spacer region (ISR) and randomly amplified polymorphic DNA (RAPD) profiles as belonging to the genera Leuconostoc (39%), Weissella (20%), Lactobacillus (23%) and Enteroccocus (18%). 16S rRNA gene sequence and species-specific PCR revealed E. casseliflavus, Lb. plantarum, Leuc. mesenteroides, Leuc. lactis and W. viridescens as the predominant species. Their distribution along chicha production process showed the presence of E. casseliflavus in maize flour while buns before 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. plantarum were recovered. Although RAPD profiles revealed intraspecies diversity, predominant LAB in the final fermented chicha were thermotolerant E. faecium (60%), probably of water origin, Leuc. lactis (27%) and Leuc. mesenteroides (13%) that persisted from the slurry fractions. Examination of these indigenous foods may provide information on unknown microbial genetic reservoirs which can be exploited as new functional starter cultures to improve nutritional and functional quality of traditional Andean foods.