Lebrun Jérémie D, Demont-Caulet Nathalie, Cheviron Nathalie, Laval Karine, Trinsoutrot-Gattin Isabelle, Mougin Christian
Irstea, UR HBAN-Ecotoxicology, 1 rue Pierre-Gilles de Gennes, CS 10030, 92761, Antony Cedex, France.
Esitpa-Ecole d'Ingénieurs en Agriculture, Agri'Terr Unit, CS 40118, 76134, Mont-Saint-Aignan, France.
Environ Sci Pollut Res Int. 2016 Feb;23(4):3036-41. doi: 10.1007/s11356-015-5145-8. Epub 2015 Aug 28.
The present study investigates the effect of metals on the secretion of enzymes from 12 fungal strains maintained in liquid cultures. Hydrolases (acid phosphatase, β-glucosidase, β-galactosidase, and N-acetyl-β-glucosaminidase) and ligninolytic oxidoreductases (laccase, Mn, and lignin peroxidases) activities, as well as biomass production, were measured in culture fluids from fungi exposed to Cu or Cd. Our results showed that all fungi secreted most of the selected hydrolases and that about 50% of them produced a partial oxidative system in the absence of metals. Then, exposure of fungi to metals led to the decrease in biomass production. At the enzymatic level, Cu and Cd modified the secretion profiles of soil fungi. The response of hydrolases to metals was contrasted and complex and depended on metal, enzyme, and fungal strain considered. By contrast, the metals always stimulated the activity of ligninolytic oxidoreductases in fungal strains. In some of them, oxidoreductases were specifically produced following metal exposure. Fungal oxidoreductases provide a more generic response than hydrolases, constituting thus a physiological basis for their use as biomarkers of metal exposure in soils.
本研究调查了金属对保存在液体培养物中的12种真菌菌株分泌酶的影响。测定了暴露于铜或镉的真菌培养液中的水解酶（酸性磷酸酶、β-葡萄糖苷酶、β-半乳糖苷酶和N-乙酰-β-葡萄糖苷酶）和木质素分解氧化还原酶（漆酶、锰过氧化物酶和木质素过氧化物酶）的活性以及生物量产量。我们的结果表明，所有真菌都分泌了大部分选定的水解酶，并且其中约50%在没有金属的情况下产生了部分氧化系统。然后，真菌暴露于金属导致生物量产量下降。在酶水平上，铜和镉改变了土壤真菌的分泌谱。水解酶对金属的反应是对比鲜明且复杂的，并且取决于所考虑的金属、酶和真菌菌株。相比之下，金属总是刺激真菌菌株中木质素分解氧化还原酶的活性。在其中一些真菌中，氧化还原酶是在金属暴露后特异性产生的。真菌氧化还原酶比水解酶提供了更普遍的反应，因此构成了将其用作土壤中金属暴露生物标志物的生理基础。
