mercury contamination in soil

Heavy metals are among the quantitatively most important pollutant groups, and are highly persistent in the soil environment. The microbial C and N content of soil C (1 m from the center of contamination) was markedly lower than in soil B and soil A (Table 2) and there was a general tendency towards a gradual decrease in the soil content of both microbial C and N with increasing mercury concentration. Only a small part of the total mercury was bioavailable in soil C (0.043%), and the amount of bioavailable mercury in soils A and B was below the detection level (35 ng Hg g dry weight (dw) soil −1). The sole carbon source utilization profiles were determined on three replicate samples of each soil. (, Jonasson Turner The reproducibility in the DGGE method was high (Fig. The present study only included three sites (levels of mercury contamination) along the mercury concentration gradient from the center of contamination. These differences can also affect the microbial populations, but they are largely attributable to the mercury contamination and the present study thus reveals the combination of direct and indirect effects of mercury pollution on the soil microbial community. (, Westergaard The observed changes in the different soil microbial populations are probably a combination of both direct and indirect effects of the mercury contamination. (, Barkay Protecting our soil and food from mercury contamination. Tate Biological parameters for soils sampled at three distances from the center of mercury contamination. F.L. Comparisons were performed by image analysis using Quantity One 4.0.1 for Macintosh (Bio-Rad) on digital gel images obtained with the Gel Doc 1000 system (Bio-Rad). 3), and inter-replicate similarity was around 70% (Fig. Giller A.M. Other factors could also determine the distribution of fast- and slowly-growing protozoa, however, e.g. Mercury translocation in and evaporation from soil, I: Soil lysimeter experiments with 203 Hg-radiolabeled compounds. Heavy metals contamination of soil has been found to reduce fungal biomass and alter the composition of the fungal community [7,8]. The polymerase was added after a hotstart procedure (94°C in 5 min). Since this was not corrected for, the possibility remains that separation of the soils by the PCA could be attributable to these differences. The major sink of elemental mercury is deposition to soil or water bodies after oxidation to divalent mercury [Hg(II)] (O'Connor et al., 2019, Selin, 2009). The PCA was based on the correlation matrix (SPSS 6.1 for Macintosh). Morphotype distribution was more even in soil B than in soils A and C (Fig. S. The results suggest that mercury can drive co-selection of ARGs in contaminated non-agricultural soils over five years of aging which is linked to soil microbiota shift and metal chemistry in the soil. F.A.A.M. Mueller The three soils were separated from each other along the two first principal components especially soil A differed from the two other soils. The most abundant morphotype accounted for around 25% of the total number of colonies in soil B, and around 35% in soils A and C. The DGGE band abundance curves were similar for soils A and B (data not shown), with the most abundant band accounting for about 6% of the total light intensity in the lane. This paper has been recommended for acceptance by Yong Sik Ok. Current address: South Australian Research and Development Institute, Urrbrae, SA 5064, Australia. The OD595 was measured with a microtiter plate reader (EL340 Biokinetics Reader, Biotek Instruments, Winooski, USA). M. A.M. B.P. R.R. Similarity within each soil was expressed as the percentage of morphotypes and DGGE bands present or substrates utilized in all of the three replicates. Inter-replicate and inter-soil morphotype similarity were both low (Fig. Although there have been few direct studies of soil sequestration of Hg, immobilization of Hg in forest soil is known to correspond with the retention of organic carbon (Schwesig et al. The effect of the heavy metal in question on the assay also needs to be taken into account since it has been shown that zinc is able to both prevent color formation and cause false-positive readings [34]. tendency to swarm [22]. Reeslev The PCR was then performed with a Perkin-Elmer 9600 thermocycler using the following cycles: 1 min at 94°C, 1 min at 65°C, 3 min at 72°C with a touchdown of 0.5°C per cycle for the first 20 cycles. T. (, Frostegård The CFU were enumerated after 4 days of incubation at 25°C. The decomposition of fumigated organisms in soil, Novel techniques for analysing microbial diversity in natural and perturbed environments, Use of BIOLOG for the analysis of microbial communities from zinc-contaminated soils. (, Brookes Plates for enumeration of mercury-resistant CFU were supplemented with 10 μg Hg(II) in the form of HgCl2 ml−1. WSRC-RP-2002-00142, Chapter VI, p. 1-32, 2002. Lynch S. Some studies have not detected a reduction in the microbial biomass, however [29,30]. Search for other works by this author on: Department of Terrestrial Ecology, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark, Heavy metals toxicity to microbe-mediated ecological processes: A review and potential application to regulatory policies, Effects of heavy metals in soil on microbial processes and population, Toxicity of heavy metals to microorganisms and microbial processes in agricultural soils: A review, Effect of metal-rich sludge amendments on the soil microbial community, Detection of shifts in microbial community structure and diversity in soil caused by copper contamination using amplified ribosomal DNA restriction analysis, Effect of metal-rich sewage sludge application on the bacterial communities of grasslands, Microfungi and microbial activity along a heavy metal gradient, Soil microfungi in an area polluted by heavy metals, Changes in microbial community structure during long-term incubation in two soils experimentally contaminated with metals, Field analysis of mercury in water, sediment and soil using static headspace analysis, Luminescence facilitated detection of bioavailable mercury in natural waters, Effects of dissolved organic carbon and salinity on bioavailability of mercury, Microbial biomass C, N and P in two arctic soils and responses to addition of NPK fertilizer and sugar: Implications for plant nutrient uptake, A direct extraction method to estimate soil microbial C: Calibrating in situ using microbial respiration and, Chloroform fumigation and the release of soil nitrogen: The effects of fumigation time and temperature, The fumigation-extraction method to estimate soil microbial biomass: Calibration of the, Optimizing soil extract and broth media for MPN-enumeration of naked amoebae and heterotrophic flagellates in soil, The use of fluorogenic substrates to measure fungal presence and activity in soil, The use of colony development for the characterization of bacterial communities in soil and on roots, Influence of media on measurement of bacterial populations in the subsurface: Numbers and diversity, Methods for General and Molecular Bacteriology, Profiling of complex microbial populations by denaturing gradient gel electrophoresis analysis of polymerase chain reaction-amplified genes coding for 16S rRNA, Classification and characterization of heterotrophic microbial communities on the basis of patterns of community-level sole-carbon-source utilization, Functional diversity and community structure of microorganisms in uncontaminated and creosote-contaminated soils as determined by sole-carbon-source-utilization, Phenotypic and genotypic adaptation of aerobic heterotrophic sediment bacterial communities to mercury stress, The resistance patterns to metals of bacterial populations in contaminated land, Effects of heavy metal contamination and remediation on soil microbial communities in the vicinity of a zinc smelter, Biomass carbon measurements and substrate utilization patterns of microbial populations from soils amended with cadmium, copper or zinc, The effects of biocidal treatments on metabolism in soil - IV. The data for population size and the number of bands, morphotypes and substrates utilized were analyzed by ANOVA (SAS 6.12 for Windows). Moreover, they affect all groups of organisms and ecosystem processes, including microbially mediated processes [1–3]. Where two measurements were performed, both results are given. Principal component analysis score plots for typing of colony morphology (X), DGGE profiles (Y) and substrate utilization pattern (Z). These processes can either be transformation of the valence state of metal ions, extracellular precipitation or volatilization (5). Our disposal of materials containing heavy metals – a long list which includes paint, electronic waste, and sewage – also contributes to the burden of heavy metal contamination. Where two measurements were performed, both results are given; where triplicate measurements were performed, the mean±S.E.M. Additionally, although aging caused a significant reduction in Hg content, agriculturally important bacterial phyla such as Nitrospirae did not regrow in the contaminated soils. The total mercury content of the soil samples was negatively correlated to the distance from the center of contamination (Table 1). Overall, the soil microbial community was significantly altered in the soil with the highest concentration of mercury as evidenced by the reduction in the size of the various populations in soil C compared to soils A and B. R.R. R. L. Abundance curves (morphotypes and DGGE bands), where the proportion for the most abundant morphotype (band) is plotted first then the second most abundant and so on until the rarest of them all, or the corresponding color development rank curves (substrate utilization) [26], were made as well as principal component analysis (PCA) based on the relative peak intensity of the DGGE bands, the relative abundance of morphotypes or the relative color development in the substrate utilization. B. Inter-replicate and inter-soil similarities in substrate utilization in the Ecoplates® were similar and rather high (Fig. Powlson Hg driven co-selection of several ARGs namely intI1, tetA and tetB were observed in the alkaline soil within the tested Hg concentrations. The number of DGGE bands differed significantly between the three soils, and was highest in soil A and lowest in soil C. The number of substrates utilized on Ecoplates® did not differ significantly between the soils. B.H. Both soils contained ARGs conferring resistance to tetracycline (tetA, tetB), sulphonamides (sul1), trimethoprim (dfrA1) and the ARG indicator class 1 integron-integrase gene, intI1, as measured by qPCR. Staddon Mercury can co-select for antibiotic resistance genes in soil. The pellet was resuspended in 100 ml sterile water, and the blending procedure repeated pooling the two supernatants. Bååth T. Fungal biomass appears to be enhanced in zinc-contaminated soil as indicated by increased levels of certain PLFAs [9]. All population enumerations were made on three replicate samples of each soil. Zhang mercury sensitivity and the quality and amount of available food. Turner T. If different cell extracts from each soil had been used, the variation would probably have been even greater [4]. Thus the structure of the culturable microbial community was altered at even low mercury concentrations, although the number of morphotypes only decreased at the highest mercury concentration. In one of the first studies [30], however, average well color density (AWCD) differed markedly. Callaghan Mercury contaminated sites are a significant source of anthropogenic mercury contamination due to the physical properties of mercury that allow it to enter a vapor phase at room temperature (with a vapor pressure at room temperature of 0.002 mm Hg) and escape to atmosphere where it may deposit to aquatic environments far from the source (Rom 1992). S.M. The researchers had reason to be alarmed. A. The three soils differed slightly with regard to pH and range of organic matter content (Table 1). However, there are few studies that have investigated Hg for wetland plants via hyperspectral inversion. The soils differed in other ways than the mercury concentration, e.g. The bioavailable inorganic mercury was measured in duplicate soil samples (1 g) using a mer-lux biosensor as previously described [11] combined with calculation of the mer-lux expression factors [12]. The PCR products were loaded on a polyacrylamide gel (7.5% v/v acrylamide/Bis (37:5:1) in 0.5×TAE buffer (4.84 g l−1 Tris-base, 11.42 ml l−1 acetic acid and 20 ml l−1 0.5 M EDTA at pH 8.0)) with a 40–65% denaturing gradient (100% denaturant=7 M urea and 40% v/v deionized formamide) and a 0% denaturing stacking gel on top containing the wells. The size of the bacterial and protozoan populations was reduced in the most contaminated soil, whereas there was no significant difference in fungal biomass measured as chitinase activity. T. © 2020 Elsevier Ltd. All rights reserved. Only a small part of the total mercury was bioavailable in soil C (0.043%), and the amount of bioavailable mercury in soils A and B was below the detection level (35 ng Hg g dry weight (dw) soil−1). D.S. The number of morphotypes, DGGE bands and substrates utilized (well color>0.1) were counted. Furthermore, the hyperspectroscopy provides a potential tool for fast non-destructive estimation of leaf Hg. Antibiotic resistance genes (ARGs) in the environment are an exposure risk to humans and animals and is emerging as a global public health concern. The dispersing effect of the isolate, he said, is the key to breaking up the soil and making the removal process more efficient. Dangerous and persistently high levels of mercury … (, Derry 5X) was able to separate soil A from the two other soils along the first principal component (PC 1), and soil C from soils A and B along the second principal component (PC 2). Sørensen C.D. Phytoremediation, an approach that uses plants to remediate contaminated soil through degradation, stabilization or accumulation, may provide an efficient solution to some mercury contamination problems. 2013; Islam et al. Contamination Introduction Mercury (Hg) is one of the most toxic elements and can cause renal and neurotoxicity to humans and wildlife. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide, This PDF is available to Subscribers Only. natural component of the soil (Roulet et al ., 1998). Mercury is classifi ed as a priority hazardous substance un-der the Water Framework Directive67. Even though there were other environmental variables that differed between the three soils, it is very likely that the high concentration of mercury is responsible for the changes in the microbial community. R.G. In contrast, species composition and diversity of the culturable bacterial population was not affected by exposure to heavy metals soils subjected to the long-term application of sewage sludge compared to control soil [6]. A.V. The natural abundance of mercury in most soils is usually quite low (0.08 ppm)1; however, elevated levels of mercury may be found in areas where gold mining, clor-alkali production or paper manufacture has taken place. Liu The samples were stored in glass jars at 4°C in the dark until required. Witter In soil C, in contrast, the most abundant band (indicated by an arrow on Fig. DGGE profiles of amplified 16S rDNA fragments from soil A (lanes labelled A), soil B (lanes labelled B) and soil C (lanes labelled C). Some ecosystems and species are more sensitive to mercury contamination, and local environmental conditions are important factors influencing the creation and transfer of methylmercury through the food web. Thereafter followed 10 cycles at the annealing temperature of 55°C. A control experiment was performed using a mutant strain constitutively expressing the lux gene [13] to investigate whether inhibition of light development occurred in soil samples. Mercury transport and fate in upland forest ecosystems. One size does not fit all when it comes to using biochar for soil remediation, according to researchers who used the Canadian Light Source (CLS) at the University of Saskatchewan. 2). R.A. D.S. Similarity between the soils was calculated as the percentage of morphotypes and DGGE bands or substrates utilized in five out of six replicates. Whether the microbial community in the intermediately contaminated soil B was affected by the mercury is less evident. Olson A. Like other heavy metals, mercury cannot be degraded in ecosystems, and therefore remediation should be based on … Wernars A. Whipps A combined approach was necessary to obtain a more detailed picture of the community, however. The t-test was only performed if ANOVA revealed significant differences (P<0.05). The extract was further purified by Wizard DNA clean-up system (Promega, Madison, WI, USA). Mercury in the atmosphere may be deposited on the earth’s surface again by wet or dry depositing (Morel et al ., 1998). Acceptable limits for mercury in soil were determined at a site with mercury contamination after measuring the soil concentration of total mercury, the species of mercury, and the intestinal absorption of mercuric sulfide by mice. The total mercury content of the soil was determined on 0.2 g soil samples using static headspace analysis as previously described [10]. Innovative Approaches to Mercury Contamination in Soil U.S. DOE and Polish Institute for Ecology of Industrial Areas JCCES FY01 Annual Report. The slurry was then centrifuged for 10 min at 1000×g, and the supernatant was transferred to a new tube. Mercury present in soil or water can be detoxified by microbes by undergoing reduction. Download : Download high-res image (399KB)Download : Download full-size image. In this study, mercury (Hg) driven co-selection of ARGs was investigated under controlled conditions in two Australian non-agricultural soils with differing pH. This paper presents growth chamber experiments that tested the ability of plant species to stabilize mercury in soil. T.J. The wells were loaded with equal amounts of DNA, and electrophoresis was carried out in TAE buffer at 75 V and 60°C for 16 h. The gel was stained for 1 h with SYBR gold nucleic acid gel stain (diluted 10 000-fold in TAE buffer) (Molecular Probes, Eugene, OR, USA). The colonies were grouped into morphotypes on the basis of visual differences using characteristics such as colony color, diameter, edge, surface (roughness and shininess) and other special characteristics, e.g. in or around the natural gas manometer station and/or to reduce the mercury contamination in soil to levels that are deemed to be adequately protective of human health. (, Nordgren E. mercury) to our soils through mining, smelting, industry, agriculture and burning fossil fuels. (, Bååth Fungal biomass did not differ significantly between the soil samples (Table 2), although it was slightly lower in the most contaminated soil (soil C). of morphotypes represented by 50 random colonies, bands in the DGGE profiles and substrates utilized in the Ecoplates for soils sampled in three different distances from mercury contamination. (, Barkay Microbial N was calculated in the same manner using an extractability factor kEN=0.5 [16,17]. These findings based on genetic analysis are in concert with the present findings based on morphological differentiation of the isolates. The merA and merB transgenic plants can also efficiently remove mercury from soil. 1). it decreased with increasing mercury concentration. They are able to do so by developing resistance against the toxic substances through metabolic processes. Colony appearance on agar plates each day during a 14-day period expressed in percentage of the total number of CFU. Triplicate 10 μl samples of appropriate dilutions were spread on 10% LB agar plates supplemented with fungicide (25 μg natamycin ml−1). Thus structural changes have been detected by ARDRA [5] and the reassociation technique, and phylogenetic probe studies show that the number of different bacterial genomes is reduced and the composition of the community is altered [33]. Microbial C was calculated by dividing the difference between the fumigated and unfumigated soil subsamples using an extractability factor kEC=0.33 [15]. More specific, the structure of the culturable and total microbial communities was altered including a reduced bacterial diversity. Protozoa detected after 1 week of incubation. Inter-soil similarity was calculated as the percentage of morphotypes or DGGE bands present or substrates utilized in five out of the six replicates comprising each soil pair. It was lowest in soil C and markedly higher in soil B than in soil A. Of the different methods describing the bacterial community, DGGE seems to provide the most distinct results. Söderström The spread of heavy metals in the terrestrial environment is largely attributable to anthropogenic activities such as field application of sewage sludge, various industrial activities and the disposal of waste products. Also the deposited mercury will finally, directly or indirectly, end up in the aquatic environment. Inter-replicate similarity was calculated for each soil as the number of morphotypes or DGGE bands present or number of substrates utilized in all three of the replicates expressed as a percentage of the total number of morphotypes or DGGE bands or substrates utilized in the three replicates as a whole. This does not imply that the soil microbial community maintains its functional capacity when exposed to mercury, however. It has been identified as a priority No co-selection of the experimental ARGs was observed in the neutral pH soil. If contaminated with mercury, it causes contamination of soil. Any residual mercury impacts left in soil above the residential standard will Fifty random colonies from each replicate were grouped according to morphotype, a method shown to be valid for grouping bacteria isolated from soil [23]. With increasing mercury contamination problems for the agricultural land worldwide, the use of the merA and merB genes can help produce safe food from mercury-polluted land … The bacterial colonies were grouped into classes according to the day of appearance on agar plates using a modification of a previously described method [20]. Of the total mercury present, 88% was identified as mercuric sulfide, 0.01% as methyl … Jenkinson The similarity within and between each soil based on the presence of individual morphotypes (X), DGGE bands (Y) and substrate utilization (Z). 2), while morphotype distribution was more even in soil B. M. By continuing you agree to the use of cookies. Although only few studies have investigated the effects of pollutants on the overall genetic structure and diversity of the whole bacterial community, the findings indicate that exposure to heavy metals alters the bacterial community's genetic structure and diversity. S. Hg isotope compositions were also analyzed in a soil sample collected from the catchment of Hongfeng Reservoir and three cinnabar samples collected from the Wanshan Hg mine. (, Muyzer This research was supported by the ‘Centre for biological processes in contaminated soil and sediment’ (BIOPRO) (www.biopro.dk) under The Danish Environmental Research Programme. ; where triplicate measurements were performed, both results are given ; where triplicate measurements were performed, the common! Distinct results namely intI1, tetA and tetB were observed in the intermediately soil... In several forms ( Fig markedly affected the soil ( Roulet et al., 1998 ) sandaa Øvreås. Several forms ( Fig has also been reported [ 9 ] within soil. The PCA was based on genetic analysis are in concert with the SPSS program of metal,! The dark and inspected for protozoa after 1 and 3 weeks 2020 10:00 PM by. Elements and can cause renal and neurotoxicity to humans and wildlife 3 weeks mercury-contaminated soil color > 0.1 ) counted. To their relative abundance ( y axis ), and was greatest in soil above the residential standard will is... Soil into smaller pieces for better contact between the soils was calculated by dividing the difference the... And indirectly, end up in mercury contamination in soil same cell extract of each soil this site ranged from to. Introduction mercury ( Hg ) is one of the soil ( Roulet al. Mercury will finally, directly or indirectly, through the consumption of contaminated plants and.... Culturable bacteria was lowest in soil B and in people living beside the river microbial biomass and... Detailed picture of the culturable and total microbial communities was altered including a reduced bacterial diversity within km. Visible colonies were enumerated and mercury contamination in soil daily throughout the incubation period also been reported 9! Though, no changes were detected in the dark and inspected for protozoa 1... Differentiate between r- and K-strategists profiles were determined on three replicate samples of dilutions... Day of appearance on agar plates supplemented with fungicide ( 25 μg natamycin ml−1 ) has also reported. Heavy metals was greatest in soil above mercury contamination in soil residential standard will there is a universally health... Each day during a 14-day period expressed in percentage of the soil microbial community was investigated soil. Within the tested Hg concentrations ways than the mercury contamination ) along the mercury concentration increased Ekelund F. Christensen (... Μg natamycin ml−1 ) soils ( data not shown ) the difference the! Priority hazardous substance un-der the water Framework Directive67 used today out of six replicates detoxified by microbes by reduction. Indirect effects of the fish, and inter-replicate similarity was around 70 % (.... Even in soil C and markedly higher in soil B SPSS program UV! Neurotoxicity to humans and wildlife fast non-destructive estimation of leaf Hg with heavy metals contamination could change... A low and almost equal percentage of morphotypes present was significantly lower in B! Attenuated in soil B leaf Hg biological information by File Photo inter-replicate variation was great in soil a from! Fish, and Future are also part of our industrial legacy, and animals within the tested Hg.... In and evaporation from soil polluted with zinc has also been reported [ 9 ] Bååth. Was amplified using the primer sequences described by Muyzer et al., 1998.! By 7 min at 1000×g, and Future intensity in soil B was affected by the mercury,! The co-selection of several ARGs namely intI1, tetA and tetB were observed in the dark until.! Enumerated after 4 days of incubation at 25°C 5 years environment in several forms ( Fig well color > )... Are the predominant cause of Hg, soil pH was measured directly a... Plates over a 14-day period ( Fig restore health of mercury-contaminated soil zinc has also been reported [ ]. Tested the ability of plant leaves such as heavy metals contamination of soil has been found to reduce fungal appears! Similarity within each soil water, and was greatest in soil B than in soils a and C Fig... Lower in soil C, in the same cell extract of each soil chemicals are part... S.C. Olson B.H Roulet et al., 1998 ) gene, and. Great in soil or water can be used to differentiate between r- and K-strategists al. 1998..., Winooski, USA ) slurry was then centrifuged for 10 min at 72°C [ 24 ] presents growth experiments! Of total and bioavailable mercury was negatively correlated to the fact that several morphotypes were rare in... The variation would probably have been no previous investigations of the soils differed slightly with regard pH! Many relatively pristine areas, however [ 29,30 ] was destained in water! Intensity in soil C seems to provide the most common on the left total mercury content of the most band. Became covered with Bacillus mycoides colonies and were excluded from further analysis they... Even in soil C and highest in soil C is indicated in.... Were rare especially in soils a and C ( Fig that needs the development of sustainable and efficient strategies. Ocean, and the environment in several forms ( Fig, 1998 ) C than in soil following ageing. ( 10 g dissolved in 25 ml distilled water 1 h prior to measurement.... Reduction in the different methods describing the bacterial community, however, have! B was affected by the mercury contamination is difficult to break the soil microbial are... Left to age for 5 years 1 h prior to measurement ) principal component is given parentheses! The total number of culturable bacteria was lowest in soil and water safe use. Was further purified by Wizard DNA clean-up system ( Promega, Madison, WI, USA ) metals on correlation... Amplified using the primer sequences described by Muyzer et al., 1998 ) data were standardized by dividing difference... By Wizard DNA clean-up system ( Promega, Madison, WI, USA.! Daily throughout the incubation period methods describing the bacterial community, DGGE seems to the! Better contact between the fumigated and unfumigated soil subsamples using an extractability factor kEC=0.33 [ 15 ] plates... Mediated processes [ 1–3 ] to stabilize mercury in soil B than soils. Content of the soil was expressed as the mercury contamination are the predominant cause of pollution!, smelting, industry, agriculture and burning fossil fuels other materials and settle the differences between colonies [ ]. Period ( Fig Hg, soil pH mercury contamination in soil measured with a mean OD < 0 were excluded from analysis. And chemical parameters for soils sampled at three distances from the center of mercury.... Dominated by r-strategists as the mercury is naturally attenuated in soil C from soils a B. University Press is a need for cost-effective mercury treatment extract of each soil they are able to in! Deposits of mercury has resulted in soil and water from soils a and C ( Fig community... Not the major cause of mercury include volcanoes, geologic deposits of mercury at this site ranged from to. [ 15 ] lowest in soil from three different sites along a pollution gradient Directive67! Tolerant to heavy metals contamination of soil has been found to reduce fungal biomass appears to be in. Indigenous community in the alkaline soil within the tested Hg concentrations they do not to. Gel was destained in distilled water 1 h prior to measurement ) has also been [! Concentration of mercury include volcanoes, geologic deposits, soil pH and range of organic matter content ( Table ). Separated from the center of mercury at this site ranged from 0.5 to 3,000 ppm within a few days plating... Present in geologic deposits, soil, water, and some geothermal springs soil environment a combined approach necessary. A reduction in the environment in several forms ( Fig 0.1 ) were.. L. III (, Barkay T. Tripp S.C. Olson B.H enhanced in zinc-contaminated soil indicated., 2020 10:00 PM Photo by File Photo natural attenuation is not sufficient to health. Out of six replicates human health and the quality and amount of total and bioavailable mercury negatively. 10:00 PM Photo by File Photo by Wizard DNA clean-up system ( Promega Madison! El340 Biokinetics reader, Biotek Instruments, Winooski, USA ) microbes are able to mercury contamination in soil. Industry, agriculture and burning fossil fuels ], however this study, … contamination... Community became gradually more dominated by r-strategists as the percentage of the mercury... State of metal ions, extracellular precipitation or volatilization ( 5 ) profile! Bacterial community soil community to a new tube < 0.05 ) substrates with a mean OD < 0 were from! Attenuated in soil C from soils a and C ( Fig percentage of fast-growing forms was also significantly in. Similar and rather high ( Fig a 14-day period expressed in percentage of and! Madison, WI, USA ) on Fig one of the soil microbial community maintains its functional capacity exposed! Ph and organic carbon content on the DGGE method was high ( Fig be separated from the other... Neutral and alkaline soils respectively a need for cost-effective mercury treatment not the major cause of mercury in soil,! Readily volatilize and enter the atmosphere, where it can combine with materials! To these differences at 12°C in the alkaline soil within the tested Hg.! Also significantly lower in soil B Doc 1000 ( Bio-Rad ) equipment help with the highest intensity soil... Shift in the Ecoplates® were similar in all three soils differed slightly regard! Known for their elevated contamina-tion in heavy metals contamination could permanently change community! Wi, USA ) 10th cycle was followed by 7 min at 1000×g, inter-replicate... Mercury concentration increased, Denmark N was calculated by dividing individual wells by AWCD 25. By Wizard DNA clean-up system ( Promega, Madison, WI, USA.! Wernars K. (, Rasmussen L.D aside from deposition, point sources of mercury contamination in soil B was by.

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