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The aim of the study was to compare the effects of stress (contamination trials) on the microorganisms in zinc-polluted soil (5,018 mg Zn kg−1 soil dry weight) and unpolluted soil (141 mg Zn kg−1 soil dw), measured as soil respiration rate. In the laboratory, soils were subjected to copper contamination (0, 500, 1,500 and 4,500 mg kg−1 soil dw), and then a bactericide (oxytetracycline) combined with a fungicide (captan) along with glucose (10 mg g−1 soil dw each) were added. There was a highly significant effect of soil type, copper treatment and oxytetracycline/captan treatment. The initial respiration rate of chronically zinc-polluted soil was higher than that of unpolluted soil, but in the copper treatment it showed a greater decline. Microorganisms in copper-treated soil were more susceptible to oxytetracycline/captan contamination. After the successive soil contamination trials the decline of soil respiration was greater in zinc-polluted soil than in unpolluted soil.

The excessive growth of filamentous bacteria and the resultant bulking of activated sludge constitute a serious problem in numerous wastewater treatment plants. Lecane inermis rotifers were previously shown to be capable of reducing the abundance of Microthrix parvicella and Nostocoida limicola in activated sludge. In the present study, the effectiveness of four Lecane clones in reducing the abundance of Type 021N filamentous bacteria was investigated. Three independent experiments were carried out on activated sludge from three different treatment plants. We found that Lecane rotifers are efficient consumers of Type 021N filaments.

Various inorganic and organic pollutants in industrial soils may adversely affect soil microorganisms and terrestrial ecosystem functioning. The aim of the study was to explore the relationship between the microbial activity, microbial biomass, and functional diversity of soil bacteria and the metals and total petroleum hydrocarbons (TPHs) in the Upper Silesian Industrial Region (Poland). We collected soil samples in pine-dominated forest stands and analyzed them according to a range of soil physicochemical properties, including metal content (cadmium, lead, and zinc) and TPH content. Metal concentrations were normalized to their toxicity to soil microorganisms and integrated in a toxicity index (TI). Soil microbial activity measured as soil respiration rate, microbial biomass measured as substrate-induced respiration rate, and the bacterial catabolic activity (area under the curve, AUC) assessed using Biolog® ECO plates were negatively related to TPH pollution as shown in multiple regressions. The canonical correspondence analysis (CCA) showed that both TPH and TI affected the community-level physiological profiles (CLPPs) of soil bacteria and the pollutants’ effects were much stronger than the effects of other soil properties, including nutrient content.Electronic supplementary materialThe online version of this article (doi:10.1007/s11270-016-2966-0) contains supplementary material, which is available to authorized users.

Scots pine (Pinus sylvestris L.) is one of the most widespread conifer species in Europe, able to tolerate a wide variety of climatic conditions. The aim of the study was to compare the activity, functional diversity and community-level physiological profiles (CLPPs) of soil microorganisms in Scots pine forests of the boreal and temperate climatic zones. The soil samples were taken from the O and A soil horizons in northern Finland (boreal pine forest, BP) and Poland (dry and mesic temperate pine forest, TDP and TMP, respectively) and measured for water-holding capacity, pH, organic C, dissolved organic C (DOC) and the total contents of N, P, Ca, Mg, K, Na and Mn. The microbial activity (multiple substrate-induced respiration rate) and functional diversification (communitylevel physiological profiles, CLPPs) were assessed using the MicroResp TM system with 22 different C substrates. The BP soils were finer textured and contained more Ca, K, Mg, Mn and Na but less N and P than the soils under the temperate forests. The pH values did not differ between the studied forests. The studied pine forests did not differ in the measured microbial properties in the O horizon. However, in the A horizon, the microorganisms from the BP soil were less active and less functionally diverse than those from the temperate forest soils. The CLPPs of the BP soils differed from those of the temperate forest soils, wherein the largest difference was from the use of carboxylic acids and amino acids. The microorganisms from the BP soils used carboxylic acids more efficiently but were much less efficient in decomposing amino acids than those from the temperate forest soils. These differences were related to the contents of DOC, N and P which are influenced by climate and bedrock properties. Our results indicate that soil microbial properties in the O horizon depend mainly on the vegetation, whereas in deeper layers, they depend to a larger extent on bedrock properties and climatic conditions.