Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche sez, Microbiologia Agraria Alimentare Ecologica, Università degli Studi di Milano, Via Celoria, 2 201333 Milano, Italy.
J Food Prot. 2010 Apr;73(4):657-62. doi: 10.4315/0362-028x-73.4.657.
The lactic acid bacteria community in traditional goat cheese produced in three dairies in Valsesia (Piemonte, Italy) was studied at different steps of the manufacturing process. These cheeses were produced from raw milk without starter bacteria, and no protocol was followed during the manufacturing process. Three hundred thirty-two isolates were characterized and grouped by results of both morphophysiological tests and random amplification of polymorphic DNA plus PCR analysis. Bacteria were identified by partial sequencing of the 16S rRNA gene. Lactococci were the dominant lactic acid bacteria in raw milk. Their initial numbers ranged from 5 to 7 log CFU ml(-1). Their levels increased during manufacturing and decreased during ripening. The growth trend for enterococci was comparable to that of lactococci, although enterococci counts were lower. Lactococcus lactis subsp. cremoris, Lactococcus garviae, and Enterococcus faecalis were the most frequently isolated species during goat cheese manufacturing, whereas the highest numbers of Enterococcus (E. faecium, E. durans, E. gilvus, and E. casseliflavus) were isolated with the greatest frequency from ripened cheese samples. Occasionally, Leuconostoc mesenteroides, Leuconostoc lactis, and Lactobacillus paraplantarum also were isolated.
研究了产自意大利瓦莱泽（皮埃蒙特）三家乳品厂的传统山羊奶酪在生产过程的不同阶段的乳酸菌群落。这些奶酪是用未经巴氏杀菌的生奶生产的，生产过程中没有遵循任何方案。通过形态生理试验和随机扩增多态性 DNA 加 PCR 分析的结果对 332 株分离株进行了特征描述和分组。通过对 16S rRNA 基因的部分测序对细菌进行了鉴定。乳球菌是生奶中的优势乳酸菌。它们的初始数量在 5 到 7 个对数 CFU/ml 之间。它们在生产过程中增加，在成熟过程中减少。肠球菌的生长趋势与乳球菌相似，尽管肠球菌的数量较低。在山羊奶酪生产过程中，最常分离到的乳球菌亚种是 Lactococcus lactis subsp. cremoris、Lactococcus garviae 和 Enterococcus faecalis，而在成熟奶酪样品中分离到的 Enterococcus（E. faecium、E. durans、E. gilvus 和 E. casseliflavus）数量最多，频率也最高。偶尔也会分离到肠膜明串珠菌、乳酸乳球菌和植物乳杆菌。
