Theses and Dissertations

Pooja Pandare

Issuing Body

Mississippi State University

Advisor

Nannapaneni, Ramakrishna

Committee Member

Schilling, M. Wes

Committee Member

Silva, Juan L.

Date of Degree

8-17-2013

Document Type

Graduate Thesis - Open Access

Major

Food Science and Technology

Degree Name

Master of Science

College

College of Agriculture and Life Sciences

Department

Department of Food Science, Nutrition and Health Promotion

Abstract

The purpose of this study is to determine the effect of temperature on inducing an alkaline-tolerance response in L. monocytogenes (Lm) serotypes 1/2a and 4b. When Lm cells were pre-exposed to a sublethal alkali pH of 9.0 at different temperatures, two main patterns were observed: (1) Alkali-stress adaptation was readily induced in Lm when cells were pre-exposed to a sublethal alkali pH of 9.0 for 5-15 min at 37°C or 22°C; and (2) Alkali-stress adaptation was not induced in Lm when cells were pre-exposed to a sublethal alkali pH of 9.0 for 1 h at 4°C. However, exposure of Lm to 4°C for 24 h enhanced its survival against lethal alkaline challenge (pH 11.5). Also, alkali-stress adaptation if occurred at 37°C or 22°C was highly stable at 4ºC even in the absence of mild alkaline stress which should be taken into account while conducting risk analysis for this pathogen.

URI

https://hdl.handle.net/11668/20177

Comments

Listeria. Alkali||stress adaptation||temperature||cold

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