Lactococci strains obtained from raw-milk Oaxaca cheese through its production process in two factories from the Tulancingo Valley, Mexico, were isolated and characterized. A total of 120 colonies were selected from the growth in M17 and MRS agars. Twenty were identified as lactococci strains, all Lactococcus lactis, and were characterized by molecular and phenotypic methods including carbohydrate use, enzymatic profile, acidifying capacity, and antibiotic and phage resistance. High phenotypic diversity was observed and confirmed among the Lactococcus lactis strains by rep-PCR fingerprints. Fifty percent of the strains were resistant to streptomycin and 35% to erythromycin. Nine isolates were considered as fast acidifying strains. The predominant volatile compounds produced were 3-methylbutanol, 3-methylbutanal and butane-2,3-dione. A selection of strains isolated in this study has shown satisfactory characteristics to be used as potential starters for the industrial production of Oaxaca cheese.

分离并鉴定了从生奶的瓦哈卡奶酪中提取的乳球菌菌株，并通过其生产过程在墨西哥图兰辛哥谷的两家工厂中进行了鉴定。从M17和MRS琼脂的生长中总共选择了120个菌落。鉴定出20株乳酸菌，均为乳酸乳球菌，并通过分子和表型方法进行了表征，包括碳水化合物的使用，酶促特性，酸化能力以及抗生素和噬菌体的耐药性。在乳酸乳球菌中观察到并确认了高表型多样性rep-PCR指纹图谱鉴定菌株。百分之五十的菌株对链霉素有抗性，百分之三十五对红霉素有抗性。九个分离株被认为是快速酸化菌株。产生的主要挥发性化合物是3-甲基丁醇，3-甲基丁醛和丁烷-2,3-二酮。在这项研究中分离出的一些菌株显示出令人满意的特性，可以用作瓦哈卡奶酪工业生产的潜在启动剂。