Revista Colombiana de Biotecnología
Print version ISSN 0123-3475
LOPEZ-ARBOLEDA, William Andrés; RAMIREZ-CASTRILLON, Mauricio; MAMBUSCAY-MENA, Luz Adriana and OSORIO-CADAVID, Esteban. Yeast diversity associated to Colombian traditional "chichas". Rev. colomb. biotecnol [online]. 2010, vol.12, n.2, pp. 176-186. ISSN 0123-3475.
In Colombia, knowledge about yeast communities has been limited because most reports have focused on yeast species with clinical relevance. The spontaneous fermentation of different substrates creates important habitats for analyzing wild yeast populations; for this reason, in this study we isolated and identified yeasts associated with the "chichas" of corn, pineapple, and "arracacha," which are traditional fermented Colombian beverages. The most representative yeasts were isolated from "chicha" during its three phases of fermentation: initial, tumultuous and final. Initially, we made a partial characterization of isolated yeasts, including macroscopic and microscopic descriptions, physiological tests, and measurement of capacity for producing spores and filaments. However, because these techniques were not sufficient for identification of isolated yeasts to the level of genus and species, the study was complemented by using molecular techniques based on restriction analysis of the ITS1-5.8S rRNA gene-ITS2. When this technique did not permit us to obtain positive results and confirm the PCR-RFLP results, we used the sequence of the D1/D2 domain of the 26S rRNA gene instead for most representative isolates. With these techniques, we identified the most representative yeast species of the three classes of "chicha": Candida tropicalis, Pichia kluyveri, Pichia guilliermondii, Hanseniapora guilliermondii, Pichia fermentans, Saccharomyces cerevisiae, Candida maltosa, Rhodotorula glutinis, Torulaspora delbrueckii, Hanseniaspora uvarum, Kazachstania exigua, Kluyveromyces marxianus, Yarrowia lypolitica, Candida parapsilosis, Debaromyces hansenii, Cryptococcus arboriformis, Saccharomyces martiniae, Dekkera anomala, Aureobasidium pullulans and Candida pseudointermedia. The preliminary characterization of isolated yeasts, based on ethanol-tolerance and salt-tolerance tests, permitted recognition of wild yeasts for possible biotechnological uses in industry.
Keywords : Yeasts; diversity; "chicha"; molecular identification; biotechnology.