1. Strategies for detection and identification of natural products produced by cyanobacteria using Geitlerinema strain Flo1 and Fischerella ambigua as model organisms
- Author
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Schrübbers, Jan, Fischer, Ulrich, and Lange, Matthias
- Subjects
knock-out mutagenesis ,polyphenol ,natural products ,non-ribosomal petide synthetases ,L-amino acid oxidase ,ddc:570 ,hydrolysable tannins ,570 Life sciences ,biology ,cyanobacteria ,HPLC-MS - 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).
- Published
- 2011