The effect of nickel contamination on the growth of litter-decomposing fungi, extracellular enzyme activities and toxicity in soil

A multi-phased approach was used to assess microbial function and the growth of litterdecomposing fungi in the Ni-contaminated organic layer of a young Pinus sylvestris forest in southern Finland.Eight fungi tested (Agaricus bisporus, Agrocybe praecox, Gymnopus peronatus, Gymnopilus sapineus, Mycena galericulata, Gymnopilus luteofolius, Stropharia aeruginosa and Stropharia rugosoannulata) were able to grow in the Ni-contaminated soil (20 mg [kg soil] -1 ).-glucosidase, -cellobiosidase, phosphomonoesterase, acetate-esterase and butyrate-esterase activities were mainly lower in the Ni-contaminated soil than in the non-contaminated soil.Low concentration of Ni (20 mg l -1 ) inhibited the growth of all fungi on humus, RBBR and ABTS containing agar colour plates.EC 50 for light inhibition in a test involving the yeast Saccharomyces cerevisiae was 294 mg Ni l -1 , which was quite high when compared with the inhibition of fungal growth on colour plates (20 mg Ni l -1 ) and the EC 50 for light inhibition of the bacterium Vibrio fischeri (85 mg Ni l -1 ).Low Ni concentrations (20 mg [kg soil] -1 ) in the present study inhibited microbial activity, the growth and enzyme production of litter-decomposing fungi.