Charakterizace promotorů Corynebacterium glutamicum regulovaných zvýšenou teplotou

Abstract

My thesis is focused on characterizationof Corynebacteriumglutamicum promoters responding to increase of temperature.C. glutamicum is the most importantrepresentativeof a gram-positive,non-pathogenic,amino-acidproducing bacteria.Its strainsare industrialproducersof glutamic acid, lysine, threonine, tryptophaneand phenylalanine(Liebl et al., l99l). Amino acids producedby microbial fermentationare used in medicine(as infusionliquids or therapeutics), chemical industry (as detergentsand cosmeticscompounds),food industry (as additives), agriculture and stockbreeding (as growth-regulatoradditives to the animalsfeed)(Hermann,2003). Althoughknowledgeof organizationsof its genesinvolvedin biosynthesis of variousaminoacidsincreasedconsiderablyduringlastyears,still littleis known about molecularsignals controllinggene expression. Since regulationof gene expressionon the level of transcriptionplays crucial role, understandingthe structureand functionof transcriptioninitiationsignals(promoters)is of primary importance.Promoters, which can be easily switahed on and off during fermentationsby externalfactorsmay ensurethe controlledoverexpressionofthe chosengenes.Therefore,the C. glutamicumpromotersrespondingto increaseof temperaturehavebeenisolated. Two differentapproachesfor isolationof the promoterswere employed. First...