The function of dye-producing microorganisms in arthropods

Grako678 D2

From 01/2004 to 12/2007

Staff: Konrad Dettner, Karlheinz Seifert, O. Meyer
Grant: GK 678/2 Graduate College 678: Ecological Significance of Natural Compounds and other Signals in Insects - from Structure to Function

Many microorganisms can synthesize dyes. The intracellular pigments can serve different functions. An example is the yellow-coloured sarcinaxanthin which protects against photo- and UV-radiation. Of particular interest are such dyes which are excreted as secondary metabolites into the environment of microorganisms. Their numerous functions are bacteriostatic or bactericidal action, chelating and acquisition of metallic ions or they serve as a source or sink for electrons. According to our working hypothesis, dyes can act as signals in the communication between a higher organism host and its intestinal microflora. The main objective of this study is the analysis of the intestinal microflora of woodlice (Crustacea/Isopoda). Previous work has already established the production of phenazine-derivates (endophenazine A~D), synthesized by species of the genus Streptomyces isolated from guts of arthropods. These phenazines showed antimicrobial activity against gram-positive bacteria, some filamentous fungi and herbicidal activity against duckweed (Lemna minor). The current project will start with a complete analysis of the gut-microflora of woodlice, particularly of dye-producers. Dyes produced by pure cultures will be isolated and structurally characterized. We will also examine their interaction with the intestinal flora and the host, particularly with respect to the function as a signal in the anticipated interspecies communication.

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