文章基本信息

标题：Selective Lactococcus Enumeration in Raw Milk
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作者：Laetitia Gemelas ; Véronique Rigobello ; Maï Huong Ly-Chatain 等
期刊名称：Food and Nutrition Sciences
印刷版ISSN：2157-944X
电子版ISSN：2157-9458
出版年度：2013
卷号：4
期号：9B
页码：49-58
DOI：10.4236/fns.2013.49A2008
出版社：Scientific Research Publishing
摘要：The Lactococcus diversity in cow and goat raw milk was investigated. To do so, a protocol had to be established for the specific enumeration of lactococci. Eight agar media and one control medium were analysed to compare their proficiency in evaluating the Lactococcus population in raw milk: M17 Nal, Elliker, modified Elliker, PCA + milk, modified KCA, modified Chalmers, Turner, FSDA. The M17 medium was used as reference. Eighteen pure strains were tested on these media for their selectivity towards lactococci: six Lactococcus species or subspecies, three Leuconostoc, three Enterococcus, two Lactobacillus, one Streptococcus thermophilus, one Pseudomonas fluorescens, one Escherichia coli and one Staphylococcus aureus. All these bacteria were chosen for their regular presence in raw milk. The KCA medium proved to be the most selective towards lactococci, on condition that 1) we discriminated the colonies using the catalase test and 2) we subtracted the Enterococcus population counted on BEA. However, it was not possible to separate the Streptococcus from the Lactococcus colonies on KCA. The “Lactococcus-like” population including these two genera was estimated at a mean level of 3.18 log(cfu)/mL and 4.14 log(cfu)/mL in cow and goat raw milk respectively. This is consistent with the data already published.
关键词：Lactococcus; Culture Media; Raw Milk; LAB; Modified KCA