This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Dalmasso, M. Articles by Demarigny, Y. Search for Related Content Social Bookmarking                         What's this?

Behavior of Lactococcus lactis subsp. lactis biovar. diacetylactis in a Four Lactococcus Strain Starter during Successive Milk Cultures

Laboratoire de Microbiologie Alimentaire. ISARA-Lyon, AGRAPOLE 23 rue Jean Baldassini, 69364 Lyon cedex 07, France

S. Prestoz

Laboratoire de Microbiologie Alimentaire. ISARA-Lyon, AGRAPOLE 23 rue Jean Baldassini, 69364 Lyon cedex 07, France

V. Rigobello

Laboratoire de Microbiologie Alimentaire. ISARA-Lyon, AGRAPOLE 23 rue Jean Baldassini, 69364 Lyon cedex 07, France

Y. Demarigny

Laboratoire de Microbiologie Alimentaire. ISARA-Lyon, AGRAPOLE 23 rue Jean Baldassini, 69364 Lyon cedex 07, France, demarigny{at}isara.fr

Cheeses are frequently made with natural whey starters (NWS). The whey from the previous cheese making is cultured and used for the next day. This practice, although essential for the development of typical sensory characteristics, can sometimes lead to acidification defects. In this work, the ability of Lactococcus lactis subsp. lactis biovar. diacetylactis to dominate over the other lactic acid bacteria (LAB) was tested in a controlled system as a possible explanation for these acidification breakdowns. A starter made of two Lc lactis subsp. lactis strains (LL), one Lc lactis subsp. cremoris strain (LC), and one Lc lactis subsp. lactis biovar. diacetylactis (LD) was added to sterilized milk. After incubation, the whey was removed and used to re-seed sterilized milk, the next day. This process was made during a five and twelve days' period. During the eight first days, the proportion of LD population increased, while the other LAB remained rather stable. Thereafter, LD strains dominated. At the same time, the diversity of LD population diminished considerably. If acidification ability of these LAB is not altered, this simplification was particularly hazardous in case of phages attack. LC and LL behavior was tested in milk containing increasing diacetyl concentrations. As long as diacetyl did not exceed a 5 ppm level — frequently measured in dairy products — its influence was impossible to detect. The selective advantage conferred by the citrate metabolism was proposed as a possible explanation for the LD population dominance. Other potential factors were also examined.

Key Words: lactic acid bacteria • Lactococcus lactis • diacetyl • starters • dairy products • cheese

Food Science and Technology International, Vol. 14, No. 6, 469-477 (2008)
DOI: 10.1177/1082013208100533


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?