Universidad Nacional de Cuyo, Bernardo de Irigoyen, San Rafael, Mendoza, Argentina.
Int J Food Microbiol. 2011 May 27;147(2):144-8. doi: 10.1016/j.ijfoodmicro.2011.04.004. Epub 2011 Apr 13.
The present study was undertaken with the purpose of selecting yeasts from wine grapes that are able to produce extracellular cold-active pectinases. After two consecutive selections yeast isolates were identified by pheno- and genotyping, and pectinolytic activity was preliminarily characterised at proximate winemaking conditions. Out of 1023 indigenous microorganisms isolated from grape skins of D.O. San Rafael (Mendoza, Argentina) viticulture region, 565 (55%) showed pectinolytic activity on plates and, among them, 96 (17%) were chosen in a primary selection. Ten isolates were finally selected for exhibiting the greatest activity at low temperature (12 °C) and identified as Aureobasidium pullulans. GM-R-22 strain demonstrated the highest pectinolytic activity (0.751 U/mL) at pH 3.5 and 12 °C. Yeast pectinases were constitutively produced. This study is the first report about strains of A. pullulans producing pectinases which are able to show good activity at low temperature. These pectinolytic strains could be of interest in wine production.
本研究的目的是从葡萄酒葡萄中筛选能够产生细胞外冷活性果胶酶的酵母。经过连续两次筛选，通过表型和基因型鉴定了酵母分离株，并在近似酿酒条件下初步表征了果胶酶活性。从阿根廷门多萨（Mendoza）葡萄酒产区 D.O. San Rafael 的葡萄皮中分离出 1023 种土著微生物，其中 565 种（55%）在平板上表现出果胶酶活性，其中 96 种（17%）在初步选择中被选中。最终选择了 10 个分离株，因为它们在低温（12°C）下表现出最大的活性，并被鉴定为出芽短梗霉。GM-R-22 菌株在 pH 值为 3.5 和 12°C 时表现出最高的果胶酶活性（0.751 U/mL）。酵母果胶酶是组成型产生的。本研究首次报道了能够在低温下表现出良好活性的产果胶酶出芽短梗霉菌株。这些果胶酶菌株在葡萄酒生产中可能具有重要意义。
