Pediococcus acidilactici PBF suşunda bakteriyosin üretiminden sorumlu genin aktarımı

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Thesis Type: Postgraduate

Institution Of The Thesis: Ankara University, Fen Bilimleri Enstitüsü, BİYOLOJİ ANABİLİM DALI, Turkey

Approval Date: 2009

Thesis Language: Turkish

Student: PELİN DOĞAN

Supervisor: ÖZLEM OSMANAĞAOĞLU

Open Archive Collection: AVESIS Open Access Collection

Abstract:

Lactic acid bacteria are widely used as starter cultures in the food industry. Because of their plasmid-coded bacteriocin production speciality, they make expire date of the food longer and thought to be potential biopreservativies. This group of bacteria become very important both industrially and scientificaly in terms of their usage in probiotic products and some of them causes food spoilage.A food-grade Pediococcus acidilactici PBF was shown to produce an antimicrobial agent active against several species of Pediococcus, Leuconostoc, Lactobacillus, Lactococcus, Staphylococcus, Enterococcus, Clostridium and Listeria; many of which are associated with food spoilage and health hazards of food origin. This antimicrobial agent is named as anti-listerial bacteriocin as it was found to be sensitive to proteolytic enzymes, effective against food-borne pathogen Listeria monocytogenes, resistant to heat and organic solvents and active over a wide range of pH. Agarose gel electrophoresis of plasmid DNA and plasmid curing experiments suggested that bacteriocin production in Pediococcus acidilactici PBF was encoded on a plasmid with a molecular weight of 9.42 kbp. Host immunity to bacteriocin was also found to be linked to this plasmid, pPF1.0. Sensitive bacteriocin nonproducer Pediococcus pentosaceus LAB strain was transformed by electroporation with gel purified pPF1.0, a plasmid DNA responsible for bacteriocin production in Pediococcus acidilactici PBF and the strain which was then started to produce /express bacteriocin was named Pediococcus pentosaceous PG