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Screening and characterization of bacteriocinogenic lactic acid bacteria from intestinal sources

Gobinath, D. (2007) Screening and characterization of bacteriocinogenic lactic acid bacteria from intestinal sources. [Student Project Report]

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Abstract

This Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page.

Item Type: Student Project Report
Additional Information: Preservation of food and beverages resulting from fermentation has been an effective form of extending the shelf-life of foods for millennia. Traditionally foods were preserved through naturally occurring fermentations; however, modern large scale production generally now exploits the use of defined strain starter systems to ensure consistency and quality in the final product. This study focuses on isolation and characterization of bacteriocinogenic LAB from intestinal sources. More than 185 organisms were isolated from various intestinal sources of which 22 was found to show antibacterial activity and of the 22, produced larger zone of inhibition were taken for the further studies. Morphological and Biochemical characterization of identified 6 chosen isolates which showed 5 as Streptococcus and 1 as Lactococcus. Growth of this organism was observed between 15oC – 40oC at pH 6.5 and it can tolerate up to 60oC for 30 minutes and 4 % NaCl. The optimum bacteriocinogenic activity is found at 30oC and 37oC. The native isolates showed antibacterial activity against various food pathogens such as Listeria sp. Staphylococcus aureus, Salmonella typhimurium and food spoilage organism like Ped. acidilactici B1153. The activity of culture filtrate with trypsin and papain showed that it is resistant to trypsin and susceptible to papain. The bacteriocins produced by the isolates are heat stable and its molecular weight is ~3 - 5.5 k Da from the Tricine SDS-PAGE. Hence the isolates could be characterized as class I bacteriocin producers. The molecular studies with PCR and restriction digestion showed that the native isolates might belong to related genus.
Uncontrolled Keywords: lactic acid bacteria intestinal sources Bacteriocin
Subjects: 500 Natural Sciences and Mathematics > 07 Life Sciences > 04 Microbiology
Divisions: Food Microbiology
Depositing User: Food Sci. & Technol. Information Services
Date Deposited: 26 Feb 2008 08:58
Last Modified: 28 Dec 2011 09:32
URI: http://ir.cftri.com/id/eprint/1655

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