title: Cadmium-induced formation of sulphide and cadmium sulphide particles in the aquatic hyphomycete Heliscus lugdunensis.
abstract: 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 exponentially Cd(2+)-concentration-dependent manner. Using light microscopy, precipitates were observed outside of the hyphae which could be determined as amorphous particles by X-ray diffraction (XRD). Energy dispersive X-ray spectroscopy (EDS) analysis indicated that these particles were mainly composed of Cd and S with an atomic ratio of 1:1, but some elements of the culture medium such as P and Cl were also present. Fungal cells exposed to Cd(2+) accumulated 12-28 μmol metal g(-1) dry mass over a period of 7-28 days. The results may indicate that sulphide could sequester excess Cd(2+) under oxygen deprived conditions and thereby reduce its toxicity via an additional avoidance mechanism of this fungus.
authors.affiliation: Institute of Biochemistry and Biotechnology, Division of Ecological and Plant Biochemistry, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120 Halle (Saale), Germany. Electronic address: dirk.dobritzsch@biochemtech.uni-halle.de.
authors.forename: Dirk
authors.initials: D
authors.lastname: Dobritzsch
authors.affiliation: Institute of Biochemistry and Biotechnology, Division of Ecological and Plant Biochemistry, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120 Halle (Saale), Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Ganz
authors.affiliation: Institute of Biochemistry and Biotechnology, Division of Ecological and Plant Biochemistry, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120 Halle (Saale), Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Rother
authors.affiliation: Digital Microscopy Facility, Mount Allison University, Sackville, NB E4L 1G7, Canada. Electronic address: jehrman@mta.ca.
authors.forename: James
authors.initials: J
authors.lastname: Ehrman
authors.affiliation: Institute of Biochemistry and Biotechnology, Division of Ecological and Plant Biochemistry, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120 Halle (Saale), Germany.
authors.forename: Renate
authors.initials: R
authors.lastname: Baumbach
authors.affiliation: Institute of Biochemistry and Biotechnology, Division of Ecological and Plant Biochemistry, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120 Halle (Saale), Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Miersch
mesh_terms: D065567:Absorption, Physiological; D000327:Adsorption; D059001:Aquatic Organisms / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D019187:Cadmium Compounds / Q000737:chemistry / Q000378:metabolism*; D011232:Chemical Precipitation; D005978:Glutathione / Q000378:metabolism; D025301:Hyphae / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D006999:Hypocreales / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D008658:Inactivation, Metabolic; D008855:Microscopy, Electron, Scanning; D003904:Mitosporic Fungi / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism; D009674:Nova Scotia; D010316:Particle Size; D045483:Rivers; D013052:Spectrometry, X-Ray Emission; D013440:Sulfides / Q000737:chemistry / Q000378:metabolism*; D066007:Toxicokinetics; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*; D014961:X-Ray Diffraction
chemical_list: D019187:Cadmium Compounds; D013440:Sulfides; D014874:Water Pollutants, Chemical; D002104:Cadmium; C034939:cadmium sulfide; D005978:Glutathione
keywords: Aquatic fungi; Cadmium; CdS crystallites; EDS; Glutathione; Heliscus lugdunensis; Sulphide