Effect on Cellular Membrane Fatty Acids in the Stressed Cells of Leuconostoc Mesenteroides: A Native Probiotic Lactic Acid Bacteria

Abstract

Probiotics are microbial cell preparations or components of microbial cells that have a beneficial effect on the health and well being of the consumer. With increasing demand for such products, a lactic acid bacterium was isolated from whey and studied for its probiotic properties. This study deals with the importance of the role of cell membrane fatty acids in response to a pH reduction. An increase of unsaturated fatty acids such as palmitoleic acid (9.1%), oleic acid (5.8%), linoeic acid (5.4%) and linolenic acid (2.8%) was found at pH 3.0, which were 103.2, 2.7, 15.6 and 9.93 fold higher, respectively, compared with the same culture grown at pH 6.5. The work was done on a native isolated culture, which was identified as Leuconostoc mesenteroides (Accession number MTCC 5209). It has antimicrobial properties against 6 toxic food pathogens and resistance to common antibiotics so as to maintain normal intestinal microflora. It has high β-galactosidase activity (278.6 micro M/100 mg protein) and can hydrolyze 3% lactose. The ability to adhere hydrocarbon provides evidence that the culture can adhere and colonize the intestinal tract. The culture is able to tolerate low pH and a high bile salt concentration, which implies the ability to survive harsh conditions of the gastrointestinal tract when orally administered in any food formulations. All these properties make it a potential probiotic culture.

Key Words:

• probiotic
• Leuconostoc
• pH resistance
• cell membrane
• fatty acids

ACKNOWLEDGEMENTS

The authors thank V. Prakash, Director, CFTRI, and S. Umesh Kumar, Head of the department, Food Microbiology, for their encouragement during this work.