Charaterization and indentification of bacteriocins from two lactococcus lactis subs lactis strains

Download

index.pdf

Date

2004

Author

Akçelik, Oya

Metadata

Show full item record

Item Usage Stats

222
views

142
downloads

In this study, bacteriocins from two L. lactis subsp. lactis isolates of Turkey origin designated OC1 and OC2, respectively, were characterized and identified. The activity spectra of the bacteriocins were determined by using different indicator bacteria including Listeria, Bacillus and Staphylococcus spp. Bacteriocins were tested for their sensitivity to different enzymes, heat treatments and pH values. Loss of bacteriocin activities after ?-amylase treatment suggested that they form aggregates with carbohydrates. Molecular masses of partially purified bacteriocins were determined by SDS-polyacrylamide gel electrophoresis. PCR amplification was carried out with different primers for the detection of structural genes of lactococcal bacteriocins. As a result of these studies, the two bacteriocins were characterized as nisin and lacticin 481, respectively. Association of the bacteriocin production with plasmid DNA was examined by using acriflavine as a plasmid curing agent. Plasmid profiles of the wild type and its non-bacteriocin producing mutants were determined by using the alkali lysis method followed by agarose gel electrophoresis. The genetic nature of industrially important characteristics of Lactococcus lactis strains were investigated through gene transfer studies via conjugation. According to the results of plasmid curing and conjugal transfer trials, it was concluded that in Lactococcus lactis subsp. lactis OC1 strain a 39,7 kb plasmid is responsible for nisin production, lactose fermentation and proteolytic activity. In Lactococcus lactis subsp. lactis OC2 strain, on the other hand, a 16 kb plasmid appeared to be responsible for lacticin 481 production and lactose fermentation.

Subject Keywords

Bacteria.

URI

http://etd.lib.metu.edu.tr/upload/2/12605075/index.pdf
https://hdl.handle.net/11511/14239

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Characterization and purification of a bacteriocin produced by Leuconostoc mesenteroides subsp. cremoris Dündar, Halil; Bozoğlu, Faruk; Department of Biotechnology (2006) In this study, a new bacteriocin isolated from a Leuconostoc mesenteroides subsp. cremoris strain was purified to homogeneity by pH mediated cell adsorption-desorption, solid phase extraction with Amberlite XAD-16, cation-exchange chromatography and hydrophobic interaction chromatography. The purification resulted in an electrophoretically pure protein that was smaller than 6 kDa as judged by SDS-PAGE. The bacteriocin was found to be very hydrophobic and cationic and could be adsorbed by synthetic calcium s...
Biochemical and genetic characterization of halobacterium salinarium strain isolated from Tuz Lake in central Anatolia Çakıcı, Özgür; Yücel, Ayşe Meral; Department of Biochemistry (2004) In this study, a halophilic archaea Halobacterium salinarium TG13 which is isolated from Tuz Lake in Central Anatolia was characterized biochemically and genetically. Halobacterium salinarium DSM3754 and Halobacterium salinarium S9 strains were used as a reference strain through the experiments. In biochemical characterization; total protein profiles of strains was compared by using 1D SDS PAGE. Total protein profile of the isolated strain has shown differences. The SDS-PAGE profile of the purified purple m...
Cloning, sequencing and expression of L-lactate dehydrogenase gene from clostridium thermocellum and isolation, characterization and transformation of various cellulolytic, thermophilic, ethanol-producing bacteria Özkan, Melek; Özcengiz, Gülay; Ögel, Zümrüt B.; Department of Biotechnology (2002) In this study, the structural gene for L-lactate dehydrogenase (LDH; EC. 1.1. 1.27) was cloned and characterized for the first time from Clostridium thermocellum 27405 in Escherichia coli. A 357 bp PCR product of predicted size was obtained with degenerate primers designed for conserved regions of Idh genes of different organisms. This amplicon was used as a probe to screen a Lambda Zap II phage library of C. thermocellum genomic DNA. One positive clone contained an insert of 2.5 kb which included an open r...
Characterization of bacteriocins from two Lactococcus lactis subsp lactis isolates Akcelik, O; Tukel, C; Özcengiz, Gülay; Akcelik, M (Wiley, 2006-03-01) In this study, bacteriocins from two Lactococcus lactis subsp. lactis isolates from raw milk samples in Turkey designated OC1 and OC2, respectively, were characterized and identified. The activity spectra of the bacteriocins were determined by using different indicator bacteria including Listeria, Bacillus and Staphylococcus spp. Bacteriocins were tested for their sensitivity to different enzymes, heat treatments and pH values. Loss of bacteriocin activities after alpha-amylase treatment suggested that they...
DNA fingerprinting and genetic characterization of Anatolian Triticum spp. using AFLP markers Yildirim, Figen; Akkaya, Mahinur (Springer Science and Business Media LLC, 2006-08-01) In this study, genetic analysis of Triticum spp. was carried out using AFLP markers. Six AFLP selective combinations were scored as presence and absence of bands for all the individual samples obtained from a single seed of each accession (70 accessions); T. baeoticum (21), T. monococcum (5), T. urartu (16), T. araraticum (7), T. dicoccoides (16) and T. dicoccon (5), resulting in 506 polymorphic AFLP bands. The phylogenetic tree showed two major clusters; one was composed of T. monococcum (AA) and T. baeoti...

Citation Formats

O. Akçelik, “Charaterization and indentification of bacteriocins from two lactococcus lactis subs lactis strains,” M.S. - Master of Science, Middle East Technical University, 2004.