<i>atp</i>D expression of probiotic <i>Lactobacillus plantarum</i> 91 under acidic environment
Keywords:
Lactobacillus plantarum, Probiotic, atpD, Acid toleranceAbstract
Lactobacillus plantarum is a flexible and versatile microorganism that inhabits a wide variety of environmental niches, including the human gastrointestinal (GI) tract. Strains of Lactobacillus plantarum have proven ability to survive gastric transit and can colonize the intestinal tract of humans and other mammals. The ability of these microorganisms to grow in harsh environment prevailing in is linked to their ability to resist acidic conditions in the stomach of healthy humans. Changes in pH in the environment have been reported to influence the expression of many genes and atp operon is chiefly involved in the acid tolerance of probiotic lactobacilli in the gut. The atpD genes are included in the category of housekeeping genes. However, the regulation of this pH-inducible phenotype has not been clearly established at the molecular level. In this study the influence of low pH on inducible gene expression in Lactobacillus plantarum 91 was investigated both in vitro and in vivo. Logarithmic phase cultures were exposed to pH 2.5, 2.0 and 1.5 for various time intervals and cultured for monitoring survivability. The cultures were able to survive at pH 1.5 to an appreciable level even after 1-3 h. In vivo study was carried out by feeding L.plantarum cultures to mice followed by isolation of bacterial RNA from stomach at different time intervals. The isolated RNA was reverse transcribed and the resultant cDNAs were subjected to RT-qPCR and the products were resolved by electrophoresis. TheatpDgene was significantly up-regulated to 1.48, 2.04 and 3.05 folds after 15, 30 and 60 min. transit in the stomach of mice. This result clearly demonstrates that atpD gene expression is essential for survival of probiotic bacteria under acidic environment prevailing in the stomach.Downloads
Published
How to Cite
Issue
Section
License
Copyright © 2001-11 Kerala Agricultural University. Some rights reserved. This journal and the individual contributions contained in it are protected under copyright by the Kerala Agricultural University and the following terms and conditions apply to their use; Photocopying Single photocopies of single articles may be made for personal use as allowed by national copyright laws. Permission of the publisher and payment of a fee is required for all other photocopying including multiple or systematic copying, copying for advertising or promotional purposes, resale, and all forms of document delivery. Permission may be sought directly from the Editor, Journal of Tropical Agriculture, Department of Agronomy, College of Horticulture,, Kerala Agricultural University, KAU PO, Thrissur 680 656, Kerala, India. (Phone: +91-487-2438325; Fax +91-487-2371040; E-mail: editor.jta@kau.in. Derivative works Subscribers may reproduce tables of contents or prepare lists of articles including abstracts for internal circulation within their institution. Permission of the Publisher is required for resale or distribution outside the institution. Permission of the Publisher is required for all other derivative works, including compilations and translations. Notice No responsibility is assumed by the Publisher for any injury and/or damage to persons or property as a matter of products, liability, negligence, or otherwise, or from any use of any methods, products, instructions or ideas contained in the material herein.