Strategien zur Detektion und Identifizierung von Naturstoffen bei Cyanobakterien am Beispiel von Geitlerinema Stamm Flo1 und Fischerella ambigua
|Other Titles:||Strategies for detection and identification of natural products produced by cyanobacteria using Geitlerinema strain Flo1 and Fischerella ambigua as model organisms||Authors:||Schrübbers, Jan||Supervisor:||Fischer, Ulrich||1. Expert:||Fischer, Ulrich||2. Expert:||Lange, Matthias||Abstract:||
Marine cyanobacteria are known as producer of a large number of bioactive substances. Geitlerinema strain Flo1 and the strain Fischerella ambigua showed production of an antibacterial substance and a brownish colored substance, respectively. These substances can be synthesized either ribosomally or on large enzyme complexes called "Non-ribosomal Peptide Synthetases" (NRPS) and "Polyketide Synthases" (PKS). Different strategies were used to prove the way of synthesis and to identify the substances. Finally knock-out mutagenesis caused by homologous recombination and HPLC-MS analyses were successfully used to identify five possible molecules that were produced by NRPS. The inhibitory effect of culture supernatant derived from strain Flo1 is caused by an L-amino acid oxidase (L-AAO). In-gel detection of the flavoenzyme using non-denaturing SDS-PAGE linked with antibacterial assays reveals that strain Flo1 produces an L-lysine oxidase with an approximate molecular weight of 55 kDa. The brownish substance secreted by Fischerella ambigua showed characteristics typical for hydrolysable tannins (polyphenols).
|Keywords:||cyanobacteria, natural products, non-ribosomal petide synthetases, HPLC-MS, knock-out mutagenesis, L-amino acid oxidase, hydrolysable tannins, polyphenol||Issue Date:||2-Dec-2011||Type:||Dissertation||URN:||urn:nbn:de:gbv:46-00102381-14||Institution:||Universität Bremen||Faculty:||FB2 Biologie/Chemie|
|Appears in Collections:||Dissertationen|
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