title: Copper and zinc affect the activity of plasma membrane H+-ATPase and thiol content in aquatic fungi.
abstract: Aquatic hyphomycetes are the major microbial decomposers of plant litter in streams. We selected three aquatic hyphomycete species with different abilities to tolerate, adsorb and accumulate copper and zinc, and we investigated the effects of these metals on H+-ATPase activity as well as on the levels of thiol (SH)-containing compounds. Before metal exposure, the species isolated from a metal-polluted stream (Heliscus submersus and Flagellospora curta) had higher levels of thiol compounds than the species isolated from a clean stream (Varicosporium elodeae). However, V. elodeae rapidly increased the levels of thiols after metal exposure, emphasizing the importance of these compounds in fungal survival under metal stress. The highest amounts of metals adsorbed to fungal mycelia were found in the most tolerant species to each metal, i.e. in H. submersus exposed to copper and in V. elodeae exposed to zinc. Short-term (10 min) exposure to copper completely inhibited the activity of H+-ATPase of H. submersus and V. elodeae, whilst zinc only led to a similar effect on H. submersus. However, at longer exposure times (8 days) the most metal-tolerant species exhibited increased H+-ATPase activities, suggesting that the plasma membrane proton pump may be involved in the acclimation of aquatic hyphomycetes to metals.
authors.affiliation: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho,Campus of Gualtar, 4710-057 Braga,Portugal.|Department of Microbiology, Faculty of Medicine, University of Porto,4200-319 Porto,Portugal.|Center for Research in Health Technologies and Information Systems, Faculty of Medicine, University of Porto,4200-319 Porto,Portugal.
authors.forename: M M
authors.initials: MM
authors.lastname: Azevedo
authors.affiliation: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho,Campus of Gualtar, 4710-057 Braga,Portugal.
authors.forename: L
authors.initials: L
authors.lastname: Guimarães-Soares
authors.affiliation: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho,Campus of Gualtar, 4710-057 Braga,Portugal.|Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho,Campus of Gualtar, 4710-057 Braga,Portugal.
authors.forename: C
authors.initials: C
authors.lastname: Pascoal
authors.affiliation: Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho,Campus of Gualtar, 4710-057 Braga,Portugal.|Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho,Campus of Gualtar, 4710-057 Braga,Portugal.
authors.forename: F
authors.initials: F
authors.lastname: Cássio
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors* / Q000737:chemistry; D001203:Ascomycota / Q000302:isolation & purification / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D003904:Mitosporic Fungi / Q000378:metabolism*; D017494:Proton Pumps / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000737:chemistry; D015032:Zinc / Q000378:metabolism*
chemical_list: D017494:Proton Pumps; D013438:Sulfhydryl Compounds; D014874:Water Pollutants, Chemical; D003300:Copper; D000251:Adenosine Triphosphatases; D015032:Zinc