HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Interpretive Summary Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wang, Y. Articles by Béal, C. Search for Related Content PubMed PubMed Citation Articles by Wang, Y. Articles by Béal, C.

Fermentation pH and Temperature Influence the Cryotolerance of Lactobacillus acidophilus RD758

¹ Institut National de la Recherche Agronomique and
² Institut National Agronomique Paris-Grignon, Génie et Microbiologie des Procédés Alimentaires, 78850 Thiverval-Grignon, France

Corresponding author: C. Béal; e-mail: beal{at}grignon.inra.fr.

The effects of 3 fermentation temperatures (30, 37, and 42°C) and 3 fermentation pH (4.5, 5, and 6) on the cryotolerance of Lactobacillus acidophilus RD758 were studied in relation to their fatty acid composition. Cryotolerance was defined as the ability of the cells to recover their acidification activity after freezing and frozen storage at –20°C. Better cryotolerance was obtained in cells grown at 30°C or at pH 5; these cells showed no loss in acidification activity during freezing and a low rate of loss in acidification activity during frozen storage. On the other hand, cells grown at 42°C or at pH 4.5 displayed poor cryotolerance. The membrane fatty acid composition was analyzed and related to the cryotolerance using principal component analysis. The improved cryotolerance observed during the freezing step was associated with a high ratio of unsaturated to saturated fatty acids, a low C18:0 content, and high C16:0 and cyclic C19:0 relative concentrations. High resistance during frozen storage was related to a high cycC19:0 concentration. Finally, the low cryotolerance observed after fermentation at pH 4.5 was explained by a low C18:2 content.

Key Words: lactic acid bacteria • temperature • pH • fatty acid composition

Abbreviation key: dtf = difference between the acidification activities measured before and after freezing; k = rate of loss in acidification activity, tc = initial acidification activity before freezing, tpH5.5 = acidification activity (time necessary to reach pH 5.5), ts = storage time, U/S = ratio of unsaturated to saturated fatty acid concentrations

This article has been cited by other articles:

				A. Rault, M. Bouix, and C. Beal Fermentation pH Influences the Physiological-State Dynamics of Lactobacillus bulgaricus CFL1 during pH-Controlled Culture Appl. Envir. Microbiol., July 1, 2009; 75(13): 4374 - 4381. [Abstract] [Full Text] [PDF]