Secretion profiles of fungi as potential tools for metal ecotoxicity assessment: a study of enzymatic system in Trametes versicolor.
The relationship between the expression of extracellular enzymatic system and a metal stress is scarce in fungi, hence limiting the possible use of secretion profiles as tools for metal ecotoxicity assessment. In the present study, we investigated the effect of Zn, Cu, Pb and Cd, tested alone or in equimolar cocktail, on the secretion profiles at enzymatic and protein levels in Trametesversicolor. For that purpose, extracellular hydrolases (acid phosphatase, β-glucosidase, β-galactosidase and N-acetyl-β-glucosaminidase) and ligninolytic oxidases (laccase, Mn-peroxidase) were monitored in liquid cultures. Fungal secretome was analyzed by electrophoresis and laccase secretion was characterized by western-blot and mass spectrometry analyses. Our results showed that all hydrolase activities were inhibited by the metals tested alone or in cocktail, whereas oxidase activities were specifically stimulated by Cu, Cd and metal cocktail. At protein level, metal exposure modified the electrophoretic profiles of fungal secretome and affected the diversity of secreted proteins. Two laccase isoenzymes, LacA and LacB, identified by mass spectrometry were differentially glycosylated according to the metal exposure. The amount of secreted LacA and LacB was strongly correlated with the stimulation of laccase activity by Cu, Cd and metal cocktail. These modifications of extracellular enzymatic system suggest that fungal oxidases could be used as biomarkers of metal exposure.
Lebrun
Jérémie D
JD
INRA, UPR 251 Physico-chimie et Ecotoxicologie des SolS d'Agrosystèmes Contaminés, Route de St Cyr, 78026 Versailles, France. jeremie.lebrun@cemagref.fr
Demont-Caulet
Nathalie
N
Cheviron
Nathalie
N
Laval
Karine
K
Trinsoutrot-Gattin
Isabelle
I
Mougin
Christian
C
D004784:Environmental Monitoring / Q000379:methods*; D005656:Fungal Proteins / Q000378:metabolism; D048788:Growth and Development / Q000187:drug effects; D006867:Hydrolases / Q000378:metabolism; D042845:Laccase / Q000378:metabolism; D008670:Metals / Q000633:toxicity*; D010544:Peroxidases / Q000378:metabolism; D012989:Soil Pollutants / Q000633:toxicity*; D055454:Trametes / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism
D005656:Fungal Proteins; D008670:Metals; D012989:Soil Pollutants; D042845:Laccase; D010544:Peroxidases; C051129:manganese peroxidase; D006867:Hydrolases