ABSTRACT
Recently, there has been growing interest in the characterization of native yeasts for their use in production of wines with regional characteristics. This study aimed to investigate Saccharomyces and non-Saccharomyces yeasts present in the spontaneous fermentation of Tannat and Marselan grape musts collected from Concordia (Entre Ríos, Argentina) over 2019, 2020, and 2021 vintages. The evolution of these fermentative processes was carried out by measuring total soluble solids, total acidity, volatile acidity, pH, ethanol concentration, and total carbon content. Isolated Saccharomyces and non-Saccharomyces yeasts were identified based on colony morphology in WL medium, 5.8S-ITS-RFLP analysis, and 26S rDNA D1/D2 gene sequencing. Two hundred and ten yeast colonies were isolated and identified as Pichia kudriavzevii, Saccharomyces cerevisiae, Hanseniaspora uvarum, Metschnikowia pulcherrima, Candida albicans, Candida parapsilosis, Pichia occidentalis, Pichia bruneiensis, Hanseniaspora opuntiae, Issatchenkia terricola, and Hanseniaspora vineae. P. kudriavzevii isolated from all vintages was associated with the spontaneous fermentation of grape musts from the Concordia region.
Subject(s)
Vitis , Wine , Fermentation , Yeasts , Wine/analysis , Saccharomyces cerevisiae/genetics , DNA, Ribosomal/geneticsABSTRACT
The study of the yeasts present in the orange juice microbiota and used in the winemaking involves the isolation, identification and production of biomass. In order to optimize the yeast growth, the nutritional requirements should be determined. The aim of this work was to determine the vitamin and other growth organic factors demand for the S. cerevisiae isolated from fermented orange juice. The culture medium was formulated with sucrose (4 g/L) as carbon and energy source (CES), urea as nitrogen source (NS), six vitamins (calcium pantothenate, pyridoxine, thiamine, biotin, niacin, folic acid), and inositol and p-aminobenzoic acid (PABA) as growth factors. The complete culture medium was used as blank, and three other media were prepared: without the vitamins and growth organic factors, with calcium pantothenate, pyridoxine, thiamine, biotin and inositol and with the latter four vitamins, but for inositol. Finally, four new media were obtained by elimination of one vitamin at a time. The temperature was set at 30 ºC and the pH, at 5.0. The S. cerevisiae present in the orange juice needs calcium pantothenate, pyridoxine, thiamine and biotin to grow adequately under aerobic conditions in a batch system, not being auxotroph for niacin, folic acid, PABA and inositol.
El estudio de levaduras autóctonas para ser usadas en la elaboración de vino de naranja, incluye aislamiento, identificación y obtención de biomasa. Para optimizar su crecimiento se deben establecer los requerimientos nutricionales. El objetivo de este estudio fue definir las necesidades de vitaminas y factores orgánicos de crecimiento de S. cerevisiae aislada de jugo de naranja fermentado. Se formuló un medio de cultivo con sacarosa (4 g/L) como fuente de carbono y energia (FCE) y urea como fuente de nitrógeno (FN), con 6 vitaminas (pantotenato de calcio, piridoxina, tiamina, biotina, niacina, ác. fólico) e inositol y ácido p-aminobenzoico (PABA) como factores de crecimiento. El medio completo se usó como testigo, preparándose además otros tres medios: con ausencia de todas las vitaminas y factores orgánicos de crecimiento, con pantotenato de Ca, piridoxina, tiamina, biotina e inositol y con esas 4 vitaminas, pero sin inositol. Finalmente, se procedió a eliminar una vitamina. Los cultivos se realizaron en aerobiosis a 30 ºC y pH 5,0. La cepa autóctona de S. cerevisiae requiere las vitaminas pantotenato de calcio, piridoxina, tiamina y biotina para crecer adecuadamente en condiciones aeróbicas en sistema batch; en cambio, no es auxótrofa para niacina, ácido fólico, PABA e inositol.
