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

This Article Full Text (PDF) 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 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 CrossRef Citing Articles via Google Scholar Google Scholar Articles by González-Márquez, H. Articles by Linden, G. Search for Related Content PubMed PubMed Citation Articles by González-Márquez, H. Articles by Linden, G. Agricola Articles by González-Márquez, H. Articles by Linden, G.

A 16 kDa protein family overexpressed by Streptococcus thermophilus PB18 in acid environments

¹Laboratoire des Biosciences de l'Aliment, Unité Associée à I'INRA, Université Henri Poincaré, Nancy 1, BP 239, 54506 Vandoeuvre-lès-Nancy Cedex, France
²Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana - Iztapalapa, 09340 Mexico, DF, Mexico

ABSTRACT

The one- and two-dimensional protein patterns of Streptococcus thermophilus PB18 in the exponential and stationary phases of growth were analysed. One-dimensional SDS-PAGE showed that a 16 kDa protein was overexpressed in stationary phase as well as 2 h after an acid shock, and that it was not expressed when the bacteria reached the stationary phase in medium with limiting lactose concentrations (5 or 10 g l^-1), in which the pH (5.5) was not as acid as in control cultures (pH 4.7, lactose 20 g l^-1). The results support the idea that this protein is expressed in response to the acidic environment and not in response to the growth phase. Two-dimensional PAGE showed that nine proteins were expressed only during the exponential phase and ten others only during the stationary phase. The 16 kDa band seen in one-dimensional SDS-PAGE corresponded to a 16 kDa protein family observed on two-dimensional SDS-PAGE/IEF gels, whose expression was increased 8.5-fold when the extracellular pH reached a critical value below 5.0. The N-terminal sequences of proteins from two spots on the two-dimensional gels (members of the 16 kDa family) were determined and found to be identical. The physiological role of this protein family has not yet been elucidated.

Author for correspondence: Patrice Bracquart. Tel: +33 3 83 91 31 25. Fax: + 33 3 83 90 15 11. e-mail: bracquar@scbiol.u-nancy.fr

This article has been cited by other articles:

				R. Wu, W. Wang, D. Yu, W. Zhang, Y. Li, Z. Sun, J. Wu, H. Meng, and H. Zhang Proteomics Analysis of Lactobacillus casei Zhang, a New Probiotic Bacterium Isolated from Traditional Home-made Koumiss in Inner Mongolia of China Mol. Cell. Proteomics, October 1, 2009; 8(10): 2321 - 2338. [Abstract] [Full Text] [PDF]

				M. Varcamonti, M. R. Graziano, R. Pezzopane, G. Naclerio, S. Arsenijevic, and M. De Felice Impaired Temperature Stress Response of a Streptococcus thermophilus deoD Mutant Appl. Envir. Microbiol., February 1, 2003; 69(2): 1287 - 1289. [Abstract] [Full Text] [PDF]

				J. A. Wouters, F. M. Rombouts, W. M. de Vos, O. P. Kuipers, and T. Abee Cold Shock Proteins and Low-Temperature Response of Streptococcus thermophilus CNRZ302 Appl. Envir. Microbiol., October 1, 1999; 65(10): 4436 - 4442. [Abstract] [Full Text]