Radiosensitivity of subterranean bacteria in the Hungarian Upper Permian Siltstone Formation

The main purpose of this work was to study the radioresistance of subterranean aerobic and anaerobic isolates from the Hungarian Upper Permian Siltstone (Aleurolite) Formation, in order to assess the safety of potential sites of future underground repositories for nuclear waste. A total of 93 isolates were studied. The radiosensitivities of these aerobic and anaerobic bacteria isolates were determined: the D10 values (decimal reducing doses) of the aerobic spore-formers lay in the range 0.80 -2.44 kGy, and those of the anaerobic spore-formers lay in the range 1.86 4.93 kGy. The D10 values of the aerobic and anaerobic vegetative isolates were much lower, in the ranges 0.11 0.57 and 0.22-0.40 kGy. respectively. The variability in bacterial radioresistance indicates the biodiversity at this potential disposal site. These results can affect the construction of a future underground repository, since knowledge of the most resistant microorganism may be of importance as concerns calculation of the time required to inactivate the bacteria surrounding the containers.     

Effect of copper-tolerant rhizosphere bacteria on mobility of copper in soil and copper accumulation by Elsholtzia splendens

The role of rhizosphere bacteria in facilitating the solubility of copper (Cu) in contaminated soil and Cu accumulation in plant were studied. The bacteria strains were isolated from the rhizosphere of Elsholtzia splendens, a Cu accumulator growing on Tonglu Mountain copper mines. After the sandy soils containing 237 mg kg(-1) were incubated with the bacteria strains, it was indicated that rhizosphere microbes played an important role in influencing the availability of water-soluble Cu in soils. Soils had greater concentrations of water-extractable Cu compared with axenic soils inoculated with different bacterial strains. Further evidence for bacterial facilitation of increased solubility of Cu in the soil was obtained using the antibiotic ampicillin (0.1 mg g(-1)). There were 36% decreases in Cu concentration in the presence of bacterial strain MS12 and ampicillin together compared with bacterial inoculation alone. Different bacterial strains had different abilities on soil water-soluble Cu. To achieve the highest rates of plant Cu accumulation, it was necessary for bacteria to be present in the rhizosphere of E. splendens. Inoculated plants supplied with 20 micromol L(-1) CuSO4 had significantly greater concentrations of Cu in shoots and roots than uninoculated plants and bacterial strain MS2 was the most effective strain in promoting plant Cu uptake. There were 2.2-fold and 2.5-fold increases in Cu accumulation in the shoots and roots of plants inoculated with strain MS2 compared to axenic controls. Furthermore, when ampicillin and the bacterial strains were added together to the nutrient solution, the Cu concentrations in roots and shoots of ampicillin-treated plants were lower than those in inoculated plants. When ampicillin was added to the nutrient solution, Cu accumulation was inhibited by about 24-44% in shoots and 20-44% in roots. The above results provided a new insight into the phytoremediation of Cu-contaminated soil.     

Application of biopreparation "Rhoder" for remediation of oil polluted polar marshy wetlands in Komi Republic

This paper describes the testing and corresponding results of the preparation "Rhoder" in comparison with several other bioremediation variants during the field trials in Komi Republic throughout 2002-2003. All bioremediation trials were performed on one vast polar marshy wetland polluted by accidental crude oil spill and uncovered by grass. After application of the "Rhoder" at the site, with an area of approximately 2000 m(2), during the cold and rainy summer of 2002 (1.5 months), the level of oil contamination decreased by 20-51%, depending on initial oil pollution (458-738 g/kg dry weight of soil). In the middle of September 2002, the treated site was covered by 70-85% with green grass. Though, during 2003, the "Rhoder" treatment was not practiced, at the end of August 2003, the site was already covered by 85-95% with green grass and the level of oil contamination further decreased by 54-79% from the initial level of oil pollution at the beginning of 2002. These results were much better compared to those from other bioremediation variants applied at this spill.     

Bioremediation of oil sludge-contaminated soil

Bioremediation has become an important method for the restoration of oil-polluted environments by the use of indigenous or selected microbial flora. Several factors such as aeration, use of inorganic nutrients or fertilizers and the type of microbial species play a major role in the remediation of oil-contaminated sites. Experiments were undertaken for bioremediation of oil sludge-contaminated soil in the presence of a bacterial consortium, inorganic nutrients, compost and a bulking agent (wheat bran). Experiments were conducted in glass troughs for the 90-day period. Bulked soil showed more rapid degradation of oil compared to all other amendments. During the experimental period, wheat bran-amended soil showed 76% hydrocarbon removal compared to 66% in the case of inorganic nutrients-amended soil. A corresponding increase in the number of bacterial populations was also noticed. Addition of the bacterial consortium in different amendments significantly enhanced the removal of oil from the petroleum sludge from different treatment units.     

Aerobic degradation of 2,4,6-TCP content in ECF bleached effluent

Elemental chlorine-free (ECF) bleach effluents from kraft mill are characterised by: a chemical organic demand/biological organic demand (COD/BOD(5)) ratio of 4, chlorophenol content with low chlorine substitution, and toxicity. The effect of increasing the concentration of 2,4,6-trichlorophenol (2,4,6-TCP) content in ECF bleaching sequence effluent on the degradative activity of bacterial communities present in an aerobic system treatment was studied. An aerobic lagoon (AL) was used as a typical secondary treatment of kraft-mill effluent. AL displays a high performance of BOD(5) degradation (up to 90%); however, only 40% of the COD was removed. Simultaneously, the AL system shows a high ability to biodegrade 2,4,6-TCP up to 237 mg/l day. Kinetic parameters of the 2,4,6-TCP biodegradation by aerobic bacteria were determined. The K(s) and K(i) values were 34.3 and 50 mg/l 2,4,6-TCP, respectively. Moreover, the tolerance of aerobic bacteria was observed up to 1.3 g/l 2,4,6-TCP.     

Monitoring of the impact of Prestige oil spill on Mytilus galloprovincialis from Galician coast

In November 2002, the Prestige oil tanker was wrecked in front of Galician coast (NW of Spain), spilling near 63,000 tons of heavy oil until February 2003. Contamination produced was very extensive (70% of Galician beaches were reached by the oil) but heterogeneous, alternating intensely affected zones with neighbour locations where the repercussion was minimal. The objective of this study was to monitor sea environment contamination caused by Prestige oil spill during an 11-month period (August 2003-June 2004, nine samplings) in two locations of Galician coast with different geographical properties (Lira and Ancoradoiro beaches), by means of chemical determination of total polycyclic aromatic hydrocarbons (TPAH) in seawater, and using as exposure biomarker TPAH content in mussel (Mytilus galloprovincialis) tissues, and as effect biomarker DNA damage in mussel gills, evaluated by the comet assay. In addition, recovery ability of the mussels was determined after a 7-day stay in the laboratory. TPAH contents in seawater were very high in the earliest samplings, but then they maintained below 200 ng L(-)(1), similar to reference seawater. However, TPAH levels in mussel tissues were more variable: they increased again from January 2004, probably due to the adverse meteorological conditions that turned over the sea bottom and dispersed the oil accumulated in sediments. In most samplings, these levels decreased during the recovery stage. DNA damage in oil-exposed mussels was significantly higher than in reference mussels, both before and after the recovery phase, but they did not differ to one another. Comet tail length was slightly reduced during the recovery stage, indicative of a certain DNA repair in exposed mussels. This study showed up the importance of monitoring sea contamination events during an extended time, not only in evaluating the presence of the contaminants in the environment but also in determining their bioaccumulation and their effect on the exposed organisms.     

Biological properties of south Russian soils: Tolerance to oil pollution

Oil pollution of south Russian soils usually leads to reduction in the abundance of ammonifying bacteria, microscopic fungi, and bacteria of the genus Azotobacter, as well as in enzyme (catalase and invertase) and cellulolytic activities. By the criterion of biological tolerance to oil pollution, these soils can be arranged in the following series: ordinary chernozems >= soddy calcareous soils = southern chernozems >= leached chernozems > brown forest soils >= gray sand soils. A regional scheme of ecological safety standards for oil contents in these soil types is proposed.     

Environmental conditions for the formation of insoluble Tc in water ponds located above paddy fields

Optimum conditions for the formation of insoluble Tc (Tc in >0.2 microm size fraction) were studied using a microcosm including water ponds above a paddy field to understand Tc behavior in such fields. In the microcosm, soluble TcO(4)(-) was converted to insoluble forms, but no changes in the form of Tc were observed in filtered microcosm samples which were microorganisms-free. The formation of insoluble Tc was inhibited by the addition of the antibiotic chloramphenicol. In addition, the reduction of soluble Tc(VII)O(4)(-) to low-valence oxide was not observed in the filtered microcosm samples, although reducing conditions were present. These results indicated that bacteria were involved in the formation of insoluble Tc. Since oxidizing conditions influence bacterial metabolism, the formation of insoluble Tc by bacteria was studied under aerobic and anaerobic conditions. The results showed that anaerobic conditions were favorable for the formation of insoluble Tc. In addition, the addition of formate as an electron donor to a microcosm sample facilitated the formation of insoluble Tc. The results suggested that insoluble Tc in the water ponds above paddy fields was caused by bacteria, which were shown to couple the oxidation of formate to the reduction of Tc(VII) during anaerobic respiration.     

Histopathology and Changes of Reproductive Parameters in Peled,Coregonus peled,from the Lower Ob Basin

Russian Journal of Ecology - Histopathological changes in the gills, liver, kidneys and gonads and heavy metal accumulation have been studied in peled (Coregonus peled) from the Lower Ob basin. It...     

Initial study on the effects of Prestige oil on human health

The big oil tanker Prestige wrecked at 130 miles from the coast of Galicia, on the Northwest of Spain, in November 19, 2002. During the accident over 40,000 tons of oil were spilled, and along the next weeks 22,000 more reached the shore in the way of three black tides. A great number of people participated in the cleaning tasks. The objective of this study was to initially evaluate the damage caused by Prestige oil in exposed individuals both from the cytogenetic and the endocrine points of view. Exposure level was determined by analysing volatile organic compounds in the environment and heavy metals in blood. Cytogenetic damage was determined by sister chromatid exchanges (SCE), and plasmatic prolactin and cortisol levels were used as biomarkers of endocrine toxicity. Finally we have determined the possible influence of GST genetic polymorphisms (GSTM1 and GSTT1 deletion polymorphisms, GSTP1 Ala105Val) on the evaluated effects. The exposed population was classified according to the performed cleaning tasks in three groups: volunteers that collaborated for 1 week (N=25), hired manual workers (N=20) and hired high-pressure cleaner workers (N=23). The control population consisted of 42 individuals. Exposure to Prestige oil caused cytogenetic damage in exposed individuals, being its effect influenced by age, sex, tobacco consumption and GSTM1 polymorphism. With regard to endocrine toxicity, our results showed that xenobiotics present in Prestige oil induced alterations in hormonal status, and thus it may be considered as an endocrine disruptor. Therefore, the selected parameters have shown to be good indicators of toxicity related to exposure to Prestige oil. In addition, data obtained point to the importance of using protective devices in preventing the effects related to the exposure.     

Long-Term Dynamics of Heavy Metal Concentrations in the Food and Liver of Shrews (g. Sorex) during High and Reduced Emissions Periods from the Copper Smelter

Russian Journal of Ecology - The long-term changes in the contents of heavy metals (Cu, Zn, Cd, Рb) in the food and liver of four shrew species of the g. Sorex, in the vicinity of the the...     

Effect of Heavy Metals (Cu,Co, Cd) on the Early Development of Mytilus edulis (Mollusca; Bivalvia)

Russian Journal of Ecology - The effect of dissolved heavy metals (Cu, Cd and Co) on the early development of blue mussel Mytilus edulis from the White Sea was studied in an acute 72-hour...     

不同农地整治措施对土壤细菌多样性的影响

为了研究不同农地整治措施对土壤细菌的影响,通过高通量测序技术,对不同农地整治措施下土壤细菌多样性与种群结构进行对比分析。结果表明:(1)从细菌多样性来看,实施农地整治的样点土壤细菌多样性显著提高;(2)从细菌种群结构来看,实施田块归并、平整土地、筑造沟渠以及土壤培肥等措施有效提高了甲基暖菌属(Methylocaldum)、亚硝化单胞菌(Nitrosomonas)、脱硫线菌属(Desulfonema)等有益菌属的丰度;(3)通过与土壤环境因子的相关性分析,酸碱度、铜和铅含量是影响农地整治区土壤细菌多样性与结构的重要因素。该研究证实了农地整治对提高土壤细菌多样性和改善土壤质量的重要作用,也为农地整治工作的开展提供了科学依据。     

Metal bioremediation through growing cells

Heavy-metal pollution represents an important environmental problem due to the toxic effects of metals, and their accumulation throughout the food chain leads to serious ecological and health problems. Metal remediation through common physico-chemical techniques is expensive and unsuitable in case of voluminous effluents containing complexing organic matter and low metal contamination. Biotechnological approaches that are designed to cover such niches have, therefore, received great deal of attention in the recent years. Biosorption studies involving low-cost and often dead/pretreated biomass have dominated the literature and, subsequently, extensive reviews focusing on equilibrium and kinetics of metal biosorption have also come up. However, the low binding capacity of biomass for certain recalcitrant metals such as Ni and failure to effectively remove metals from real industrial effluents due to presence of organic or inorganic ligands limit this approach. At times, when pure biosorptive metal removal is not feasible, application of a judicious consortium of growing metal-resistant cells can ensure better removal through a combination of bioprecipitation, biosorption and continuous metabolic uptake of metals after physical adsorption. Such approach may lead to simultaneous removal of toxic metals, organic loads and other inorganic impurities, as well as allow optimization through development of resistant species. However, sensitivity of living cells to extremes of pH or high metal concentration and need to furnish metabolic energy are some of the major constraints of employing growing cells for bioremediation. The efforts to meet such challenges via isolation of metal-resistant bacterial/fungal strains and exploitation of organic wastes as carbon substrates have began. Recent studies show that the strains (bacteria, yeast and fungi) isolated from contaminated sites possess excellent capability of metal scavenging. Some bacterial strains possess high tolerance to various metals and may be potential candidates for their simultaneous removal from wastes. Evidently, the stage has already been set for the application of metal-resistant growing microbial cells for metal harvesting. This review focuses on the applicability of growing bacterial/fungal/algal cells for metal removal and the efforts directed towards cell/process development to make this option technically/economically viable for the comprehensive treatment of metal-rich effluents.     

State of the art in high sea-state oil pollution response capabilities

This paper describes the state-of-the-art approaches to dealing with the two major types of open-water pollution incidents encountered in bad weather — a tanker stranding where the oil is still contained within the tanks, and an actual spillage from a damaged tanker or fixed source.In the stranding case, the cargo off-loading approach is compared with cargo jettisoning (pumping part of the cargo overboard) and stabilization approaches.In the spillage case, the basic approaches that are feasible are skimming and the use of dispersants. The advantages of each are discussed. Systems including large containment barriers are estimated to be less effective than direct-acting skimmers because of the operational control problems in high sea states. Effective direct-acting skimmers are not in wide-spread use at present, although several systems are under development. Dispersant systems are estimated to have the highest sea-state operating capability, particularly aircraft-application systems, which could be effective in conditions up to where a slick is rapidly dispersed through natural wave turbulence.     

Migration of Heavy Metals from Polluted Soil to Plants and Lichens under Conditions of Field Experiment on the Kola Peninsula

Russian Journal of Ecology - We have carried out a field experiment to study the migration of Ni, Cu, and Co from the organic horizon of Al–Fe-humus podzols polluted with heavy metals (HMs)...     

Exploring correlation between redox potential and other edaphic factors in field and laboratory conditions in relation to methane efflux.

Methane is primarily a biogenic gas, which is implicated in global warming. Although its production in the anoxic conditions is regulated by several edaphic factors, aquatic macrophytes also influence methane emission by providing aerenchyma to act as chimney for CH4 transport from the sediment to troposphere, by releasing root exudates to the sediment to serve as substrate for methanogenic bacteria and by transporting atmospheric O2 to rhizosphere, which stimulates CH4 consumption. Among the edaphic factors, redox potential (Eh) is the most important, which largely determines the action of methanogenic bacteria. Hence, a study was undertaken first to find out the correlation between CH4 emission and edaphic factors in the field conditions and then to understand the relationship between Eh and other edaphic factors. The field studies revealed that natural wetlands were the major source of CH4 emission, and the vegetation plays an important role in CH4 emission from the water bodies. However, it was very difficult to establish a strong relationship between the CH4 emission and the edaphic factors in the field conditions due to other limiting factors and their constant fluctuations. In this connection, the laboratory experiments exhibited that soil temperature, pH, moisture regime and incubation period were negatively correlated with Eh, which determines the initiation of methanogenic process. However, organic carbon and the water regime over the soil surface did not show any impact on Eh in this study.     

Effects of Land Use Changes on the Landscape Composition: A Comparison Between Finnish and Russian Karelia

During the last 50 years the practising and intensity of agriculture and forestry have differed considerably between Finnish and Russian Karelia. We studied the effects of different land use practices on the landscape composition in the two countries using the road transect sampling along four study routes (99-121 km) between 1997 and 1999. Effective environmental management in Finland has resulted in more distinct agricultural land types, more even distribution of the different age classes of forests, and the higher abundance of coniferous forests. Fields (mean percentage of the landscape: Finland 28%, Russia 13%), clearcuts and sapling stands (15%, 6%), and young forests (23%, 9%) were more typical elements of the Finnish landscape, whereas settlements (9%, 13%), semi-natural grasslands (3%, 7%), and mature forests (20%, 49%) were more characteristic of the Russian landscape. Landscape-level differences between the two countries may have various effects on the diversity of fauna and flora inhabiting Finnish and Russian Karelia.     

Biological diversity of nitrile-metabolizing bacteria in soils of the Perm region affected by human activities

The diversity of bacteria metabolizing nitriles of carbonic acids was studied in soils of the Perm region affected by human activities. Effective methods for selective isolation of cultures possessing the nitrile hydratase and nitrilase activities were developed. Most microorganisms capable of utilizing nitriles were Grampositive Nocardia-like bacteria of the genus Rhodococcus. Isolates with a detectable nitrilase activity were also represented by Gram-negative forms (Gram-negative aerobic/microaerophilic bacilli and cocci of the genera Pseudomonas, Azomonas, Azotobacter, and Acidovorax). Two enzyme systems for nitrile hydrolysis were found in 27% of cultures. The nitrile hydratase and nitrilase activities of the studied strains exceeded these enzymatic activities in bacteria isolated from native soils, which indicates that natural selection of saprophytic microflora occurs in chemically altered soils.     

三峡库区172 m蓄水位实现后干流水体溶解态重金属含量变化特征

从2008年至2010年连续两年,对三峡库区涪陵至巴东段水体溶解态重金属含量进行监测,分析三峡水库自2008年首次以172 m高水位试验性蓄水以来水体溶解态重金属含量变化特征及其影响因素。结果表明：水体溶解态重金属含量在丰水期低水位时含量较高,而在平水期和枯水期高水位蓄水时,水体重金属含量较低,丰水期时水体溶解态重金属含量虽然相对较高,但仍然达到《地表水环境质量标准》(GB 3838 2002)Ⅰ类水域标准。重金属在水体与沉积物和消落带土壤中含量并无明显相关性,沉积物和消落带土壤重金属对水体溶解态重金属含量分布影响较小。库区水环境因素在丰水期和平水期、枯水期呈现出明显差异特征,特别是汛后水体悬浮物SS含量远低于丰水期。三峡水库水环境因素的变化对重金属的分配有着重要作用,丰水期过后三峡库区水体pH值和DO升高,水温和Eh降低,SS含量显著下降,水环境因素、气象条件、水位调度等因素的变化致使水体溶解态重金属含量降低