Instituto de Lactología Industrial (INLAIN, UNL - CONICET), Santa Fe, Argentina.
J Appl Microbiol. 2013 Aug;115(2):434-44. doi: 10.1111/jam.12228. Epub 2013 Jun 7.
The aim of this work was to identify 20 yeasts isolated from autochthonal cheese starters and evaluate their technological and functional properties.
The capacities of the yeasts to grow at different temperatures, pH, NaCl and lactic acid concentrations as well as the proteolytic and lipolytic activities were studied. Moreover, survival to simulated gastrointestinal digestion, hydrophobicity, antimicrobial activity against pathogens and auto- and co-aggregation abilities were evaluated. The sequentiation of a fragment from the 26S rDNA gene indicated that Kluyveromyces marxianus was the predominant species, followed by Saccharomyces cerevisiae, Clavispora lusitaniae, Kluyveromyces lactis and Galactomyces geotrichum. RAPD with primer M13 allowed a good differentiation among strains from the same species. All strains normally grew at pH 4.7-5.5 and temperatures between 15 and 35°C. Most of them tolerated 10% NaCl and 3% lactic acid. Some strains showed proteolytic (eight isolates) and/or lipolytic (four isolates) capacities. All strains evidenced high gastrointestinal resistance, moderate hydrophobicity, intermediate auto-aggregation and variable co-aggregation abilities. No strains inhibited the growth of the pathogens assayed.
Some strains from dairy sources showed interesting functional and technological properties.
This study has been the first contribution to the identification and characterization of yeasts isolated from autochthonal cheese starters in Argentina. Many strains could be proposed as potential candidates to be used as probiotics and/or as co-starters in cheese productions.
本研究旨在从本土奶酪发酵剂中分离出 20 株酵母，并评估其技术和功能特性。
研究了酵母在不同温度、pH 值、NaCl 和乳酸浓度下的生长能力以及蛋白酶和脂肪酶活性。此外，还评估了酵母的耐模拟胃肠道消化能力、疏水性、抗病原体活性以及自聚集和共聚集能力。26S rDNA 基因片段序列分析表明，马克斯克鲁维酵母是优势种，其次是酿酒酵母、清酒假丝酵母、乳酸克鲁维酵母和地衣芽孢杆菌。用引物 M13 进行的 RAPD 分析可以很好地区分同一物种的菌株。所有菌株通常在 pH 值为 4.7-5.5 和 15-35°C 之间的温度下生长。它们大多能耐受 10%NaCl 和 3%乳酸。一些菌株具有蛋白酶（8 株）和/或脂肪酶（4 株）活性。所有菌株均表现出较高的胃肠道抗性、中等疏水性、中等自聚集能力和可变共聚集能力。没有菌株能抑制所测试病原体的生长。
一些来自乳制品的菌株具有有趣的功能和技术特性。
本研究首次对从阿根廷本土奶酪发酵剂中分离出的酵母进行了鉴定和特性研究。许多菌株可被提议作为益生菌和/或奶酪生产中的共发酵剂的潜在候选菌株。
