Juergen Miersch

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We studied heavy metal stress responses of two Fontinalis species, F. antipyretica and F. dalecarlica, collected from two habitats in Germany and Canada. The capacities of the two species for extracellular adsorption (biosorption) and intracellular uptake (bioaccumulation) of Cadmium (Cd2+) were investigated in the laboratory. Time-dependent Cd2+ adsorption(More)
A HPLC-fluorescence method, using the fluorophore SBD-F (ammonium-7-fluorobenz-2-oxa-1,3-diazole-4-sulfonate), was adapted for the quantification of metallothioneins and their isoforms from the Moroccan mussel Mytilus galloprovincialis. The method was first optimized using a rabbit liver metallothionein. The effects of EDTA, tris(2-carboxyethyl)phosphine,(More)
The effects of cadmium, copper, and zinc on the growth of ten strains ofaquatic hyphomycetes were investigated. On a solid medium, Cd and Cu reducedradial growth of most strains by 50% at concentrations between150–400 µM; in a liquid medium, the strains were more sensitive.The inhibitory effects of zinc were much less severe. Two isolates(Articulospora(More)
The objective of this work is to investigate the possibilities for introducing the currently used Nα-, NG- and C-protective groups into the canavanine molecule and the preparation of canavanines selectively blocked at the guanidino function. These novel compounds will find application in the synthesis of canavanine derivatives expected to be amino acid(More)
The uptakes of the linear polyol ribitol and ofd-glucose byCandida guillermondii were found to be carrier-mediated and to require metabolic energy. In glucose-grown cells ribitol possibly enters by simple diffusion but after an induction period a specific transport system is synthesized, inhibitable by higher concentrations of arabinitols, xylitol, mannitol(More)
The pyruvic acid thiosemicarbazone was found to inhibitin vitro the soluble ornithine carbamoyl transferase as well as the enzyme in a mitochondria-rich cell fraction. For proving the inhibition of ornithine carbamoyl transferase in mitochondria-rich fraction a new method for DEAE-thin-layer chromatography of radiocarbon labelled citrulline and ornithine(More)
Freshwater fungi which can survive under metal exposure receive increasing scientific attention. Enhanced synthesis of sulphide and glutathione but no phytochelatin synthesis in response to cadmium (up to 80 μM Cd(2+) in the medium) was measured in the aquatic hyphomycete Heliscus lugdunensis. Up to 25 μmol g(-1) dry mass the fungus formed sulphide in an(More)
The structural analog of amino acidl-arginine,l-canavanine (2-amino-4-guanidinooxybutyric acid), is found in 26 cultivars of alfalfa. Its concentration ranges from 6 to 16 mg/g of dry seeds. Canavanine represented more than 70% of the total soluble nitrogen in seeds. Practically all of the canavanine was stored in the cotyledons. Comparison is made of the(More)
so is t im P h a s e n k o n t r a s t m i k r o s k o p insbesondere bet den Zellke rnen der s t r u k t u r v e r g r 6 b e r n d e Einflul3 des a l ten Ver fah rens (Fig. I a) gegenfiber d e m n e u e n (Fig. t b) klar zu e rkennen . Der E r h a l t u n g s z u s t a n d der Zellen wi rk t s ich a u c h auf die A u t o r a d i o g r a m m e aus. Ube r(More)