Role of Sigma B Factor in the Alkaline Tolerance Response of Listeria monocytogenes 10403S and Cross-Protection against Subsequent Ethanol and Osmotic Stress

$37.00 plus tax (Refund Policy)

Buy Article:

Abstract:

Many of the considerable abilities of Listeria monocytogenes to persist and grow in a wide range of adverse environmental conditions are thought to be at least partly under the control of the alternative sigma factor (σB), encoded by the sigB gene. However, little is known about the role of this master regulon in the impressive ability of Listeria to persist and grow under conditions of alkaline pH. In this study, Northern blot analysis of parent Listeria mRNA revealed that alkali adaptation (pH 9.5 for 1 h) significantly increased the expression of sigB-derived mRNA. The study included a comparison of the relative survival of mid-exponential populations of adapted and nonadapted parent type (σB expressing) and mutant (not σB expressing, ΔsigB) Listeria strains during subsequent alkaline (pH 12.0), osmotic (25% NaCl, wt/vol), or ethanol (16.5%) stress. Alkali-adapted parent strains were more resistant to pH 12.0 than were adapted ΔsigB type strains, but both alkali-adapted parent and ΔsigB strains were more resistant to pH 12.0 than were nonadapted strains. Alkali-adapted parent strains were more resistant to osmotic stress than were adapted ΔsigB type strains. No significant differences in viability were observed between alkali-adapted parent and ΔsigB strains after ethanol stress, suggesting that cross-protection against osmotic stress is mediated by σB whereas cross-protection against ethanol is σB independent. Overall, alkali-induced cross-protection against osmotic and ethanol challenges may have serious implications for food safety and human health because such stress conditions are routinely used as part of food preservation and surface cleaning processes.

Document Type: Research Article

Affiliations: 1: Food Microbiology Research Unit, University of Ulster, Northern Ireland BT37 0QB, United Kingdom 2: Microbiology Group, Department of Biological Sciences, Illinois State University, Normal, Illinois 61790-4120, USA

Publication date: July 1, 2008

More about this publication?
  • IAFP members must first sign in on the right to access full text articles of JFP

    First published in 1937, the Journal of Food Protection®, is a refereed monthly publication. Each issue contains scientific research and authoritative review articles reporting on a variety of topics in food science pertaining to food safety and quality. The Journal is internationally recognized as the leading publication in the field of food microbiology with a readership exceeding 11,000 scientists from 70 countries. The Journal of Food Protection® is indexed in Index Medicus, Current Contents, BIOSIS, PubMed, Medline, and many others.

    Print and online subscriptions are available to Members and Institutional subscribers. Online visitors who are not IAFP Members or journal subscribers will be charged on a pay-per-view basis. Information can be obtained by calling +1 800.369.6337; +1 515.276.3344; fax: +1 515.276.8655, E-mail: info@foodprotection.org or Web site: www.foodprotection.org
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Membership Information
  • Information for Advertisers
  • ingentaconnect is not responsible for the content or availability of external websites
Related content

Tools

Favourites

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more