Response of denitrification genes <Emphasis Type="Italic">nirS</Emphasis>, <Emphasis Type="Italic">nirK</Emphasis>, and <Emphasis Type="Italic">nosZ</Emphasis> to irrigation water quality in a Chinese agricultural soil

Purpose  

Denitrification is an important biochemical process in global nitrogen cycle, with a potent greenhouse gas product N₂O. Wastewater irrigation can result in the changes of soil properties and microbial communities of agricultural soils. The purpose of this study was to examine how the soil denitrification genes responded to different irrigation regimes.     

Exposure reduction of seed treatments through dehusking behaviour of the wood mouse <Emphasis Type="Bold">(</Emphasis><Emphasis Type="Italic">Apodemus sylvaticus</Emphasis><Emphasis Type="Bold">)</Emphasis>

Background, aim and scope  

Seed treatments are widely used on cereals and other annual crops throughout Europe. Most of the formulated pesticide is found on the outside of the seed, the husk. Risk assessments of seed treatments are especially needed for granivorous mice living in the agricultural landscape e.g. for registration using the guidance for risk assessment for birds and mammals (EFSA 2009). The dehusking of seeds before consumption is a known behaviour of these mammals, but so far, no quantitative data on the reduction of exposure of seed treatments by dehusking were published. Therefore, we aimed at providing a first quantitative estimate of this behaviour-related exposure reduction for the wood mouse (Apodemus sylvaticus) with different seed types.     

Enzymatic basis for fungicide removal by <Emphasis Type="Italic">Elodea canadensis</Emphasis>

Purpose  

Plants can absorb a diversity of natural and man-made toxic compounds for which they have developed diverse detoxification mechanisms. Plants are able to metabolize and detoxify a wide array of xenobiotics by oxidation, sugar conjugation, glutathione conjugation, and more complex reactions. In this study, detoxification mechanisms of dimethomorph, a fungicide currently found in aquatic media were investigated in Elodea canadensis.     

Composition changes in the cuticular surface lipids of the helophytes <Emphasis Type="Italic">Phragmites australis</Emphasis> and <Emphasis Type="Italic">Juncus effusus</Emphasis> as result of pollutant exposure

Aim of the study  

Helophytes like rush and reed are increasingly used for phytoremediation of contaminated water. This study characterises the response of rush and reed plants to chemical stressors such as chlorobenzene, benzene and methyl-tert-butyl ether. The extractable wax layer of the cuticle was chosen for detailed investigations due to its multiple, particularly, protective functions for plants and its easy availability for analysis.     

Bacterial community composition characterization of a lead-contaminated <Emphasis Type="Italic">Microcoleus</Emphasis> sp. consortium

Introduction  

A Microcoleus sp. consortium, obtained from the Ebro delta microbial mat, was maintained under different conditions including uncontaminated, lead-contaminated, and acidic conditions.     

Uranium biosorption by <Emphasis Type="Italic">Padina</Emphasis> sp. algae biomass: kinetics and thermodynamics

Introduction  

Kinetic, thermodynamic, and equilibrium isotherms of the biosorption of uranium ions onto Padina sp., a brown algae biomass, in a batch system have been studied.     

How life history contributes to stress response in the Manila clam <Emphasis Type="Italic">Ruditapes philippinarum</Emphasis>

Introduction  

Within the last decade, numerous studies have investigated the role of environmental history on tolerance to stress of many organisms. This study aims to assess if Manila clams Ruditapes philippinarum may react differently to cadmium exposure and trematode parasite infection (Himasthla elongata) depending on their origin and environmental history in Arcachon Bay (France).     

Energy budget in <Emphasis Type="Italic">Daphnia magna</Emphasis> exposed to natural stressors

Background, aim, and scope  

Climate changes are nowadays an important issue of concern, and it is expected that in the near future it will be intensified, leading to extreme environmental conditions. These changes are expected to originate additional sources of stress; therefore, the exposure of organisms to natural stressors is receiving an increased importance in risk assessment. Organisms tend to avoid extremely environmental conditions looking for optimum conditions. This work aimed to evaluate the effects of natural stressors on the energetic reserves of Daphnia magna using the quantification of lipids, proteins, and sugars.     

Chlorpyrifos degradation by the cyanobacterium <Emphasis Type="Italic">Synechocystis</Emphasis> sp. strain PUPCCC 64

Background, aim, and scope  

Indiscriminate use of insecticides leads to environmental problems and poses a great threat to beneficial microorganisms. The aim of the present work was to study chlorpyrifos degradation by a rice field cyanobacterium Synechocystis sp. strain PUPCCC 64 so that the organism is able to reduce insecticide pollution in situ.     

Performance of <Emphasis Type="Italic">Eleocharis macrostachya</Emphasis> and its importance for arsenic retention in constructed wetlands

Introduction  

Arsenic (As) can be removed from water via rhizofiltration using phytostabilizing plants. The aim of this study was to investigate the performance of Eleocharis macrostachya in constructed wetland prototypes, as well as the plant's arsenic mass retention and the distribution of As along the wetland flow gradient and the soil in the wetland mesocosmos.     

Degradation of poly (lactic acid) and nanocomposites by <Emphasis Type="Italic">Bacillus licheniformis</Emphasis>

Background, aim, and scope  

The disposal problem due to non-degradable petroleum-based plastics has raised the demand for biodegradable polymers. The degradation of poly (lactic acid) (PLA) has been studied for several years, but the understanding of involved mechanisms is still incomplete. Based on our previous studies, and it is hypothesized an enzymatic involvement, the aim of this study was to continue investigations on the degradation of PLA and its nanocomposites by Bacillus licheniformis.     

Statistical analysis and isotherm study of uranium biosorption by <Emphasis Type="Italic">Padina</Emphasis> sp. algae biomass

Introduction  

The application of response surface methodology is presented for optimizing the removal of U ions from aqueous solutions using Padina sp., a brown marine algal biomass.     

Some microbial characteristics of mussels (<Emphasis Type="Italic">Mytilus galloprovincialis</Emphasis>) in coastal city area

Purpose  

The aim of this work was to determine some microbial characteristics of Mytilus galloprovincialis harvested from four stations, located in Izmir coastal area (Eastern Aegean Sea, Turkey). The area along the Izmir coast is densely populated, and it includes extensive agricultural lands, industrial and domestic discharge. Shellfish contamination from sewage-polluted waters is very important for public health.     

Genetic ecotoxicology of asbestos pollution in the house mouse <Emphasis Type="Italic">Mus musculus domesticus</Emphasis>

Purpose  

We tested the genetic diversity in wild mice (Mus musculus domesticus) inhabiting the asbestos-polluted area as a model for the long-term mutagenic effect of asbestos. Hazardous effects of deposited asbestos persist in the environment because of low rate of fiber disintegration. The upper layers of the soil in the vicinity of a former asbestos factory are nearly “saturated” with asbestos fibers and dust. Natural populations of mice dwell in this area and are constantly exposed to asbestos fibers.     

Calcium invigorates the cadmium-stressed <Emphasis Type="Italic">Brassica napus</Emphasis> L. plants by strengthening their photosynthetic system

Introduction  

Cadmium (Cd) in plants interrupts numerous metabolic processes and reduces the water and nutrient uptake that cause chlorosis, growth retardation, and ultimately plant death. Response of Brassica napus L. to calcium (Ca) enrichment in growth medium for reducing Cd toxicity stress by strengthening the photosynthesis organelles and their functionality was explored in this study.     

Zinc tolerance and uptake by <Emphasis Type="Italic">Arabidopsis halleri ssp. gemmifera</Emphasis> grown in nutrient solution

Background, aim, and scope  

Zinc is an essential micronutrient element but its concentrations found in contaminated soils frequently exceed those required by the plant and soil organisms, and thus create danger to animal and human health. Phytoremediation is a technique, often employed in remediation of contaminated soils, which aims to remove heavy metals or other contaminants from soils or waters using plants. Arabidopsis (A.) halleri ssp. gemmifera is a plant recently found to be grown vigorously in heavy metal contaminated areas of Japan and it contained remarkably high amount of heavy metals in its shoots. However, the magnitude of Zn accumulation and tolerance in A. halleri ssp. gemmifera need to be investigated for its use as a phytoremediation plant.     

Degradation and detoxification of acid orange 52 by <Emphasis Type="Italic">Pseudomonas putida</Emphasis> mt-2: a laboratory study

Introduction  

Acid orange 52 (AO52), extensively used in textile industries, was decolorized by Pseudomonas putida mt-2. AO52 azoreduction products such as N,N′-dimethyl-p-phenylenediamine (DMPD) and 4-aminobenzenesulfonic acid (4-ABS), were identified in the static degradation mixture. These amines were identified only in media of static incubation, which is consistent with their biotransformation under shaken incubation (aerobic conditions).     

Toxicity of cobalt-complexed cyanide to <Emphasis Type="Italic">Oncorhynchus mykiss,Daphnia magna</Emphasis>, and <Emphasis Type="Italic">Ceriodaphnia dubia</Emphasis>

Background Cobalt cyanide complexes often result when ore is treated with cyanide solutions to extract gold and other metals. These have recently been discovered in low but significant concentrations in effluents from gold leach operations. This study was conducted to determine the potential toxicity of cobalt-cyanide complexes to freshwater organisms and the extent to which ultraviolet radiation (UV) potentiates this toxicity. Tests were also conducted to determine if humic acids or if adaptation to UV influenced sensitivity to the cyanide complexes. Methods Rainbow trout (Oncorhynchus mykiss), Daphnia magna, and Ceriodaphnia dubia were exposed to potassium hexacyanocobaltate in the presence and absence of UV radiation, in the presence and absence of humic acids. Cyano-cobalt exposures were also conducted with C. dubia from cultures adapted to elevated UV. Results With an LC50 concentration of 0.38 mg/L, cyanocobalt was over a 1000 times more toxic to rainbow trout in the presence of UV at a low, environmentally relevant irradiance level (4 μW/cm² as UVB) than exposure to this compound in the absence of UV with an LC50 of 112.9 mg/L. Toxicity was immediately apparent, with mortality occurring within an hour of the onset of exposure at the highest concentration. Fish were unaffected by exposure to UV alone. Weak-acid dissociable cyanide concentrations were observed in irradiated aqueous solutions of cyanocobaltate within hours of UV exposure and persisted in the presence of UV for at least 96 hours, whereas negligible concentrations were observed in the absence of UV. The presence of humic acids significantly diminished cyanocobalt toxicity to D. magna and reduced mortality from UV exposure. Humic acids did not significantly influence survival among C. dubia. C. dubia from UV-adapted populations were less sensitive to metallocyanide compounds than organisms from unadapted populations. Conclusions The results indicate that metallocyanide complexes may pose a hazard to aquatic life through photochemically induced processes. Factors that decrease UV exposure such as dissolved organic carbon or increased pigmentation would diminish toxicity.     

Decolouration of azo dyes by <Emphasis Type="Italic">Phanerochaete chrysosporium</Emphasis> immobilised into alginate beads

Background, aim and scope  

Because of high discharged volumes and effluent composition, wastewater from the textile industry can be considered as the most polluting amongst all industrial sectors, thus greatly requiring appropriate treatment technologies. Although some abiotic methods for the reduction of several dyes exist, these require highly expensive catalysts and reagents. Biotechnological approaches were proven to be potentially effective in the treatment of this pollution source in an eco-efficient manner. The white-rot fungi are, so far, the most efficient microorganisms in degrading synthetic dyes. This white-rot fungi’s property is due to the production of extracellular lignin-modifying enzymes, which are able to degrade a wide range of xenobiotic compounds because of their low substrate specificity. In this paper, we studied the ability of the white-rot fungus Phanerochaete chrysosporium immobilised into Ca-alginate beads to decolourise different recalcitrant azo dyes such as Direct Violet 51 (DV), Reactive Black 5 (RB), Ponceau Xylidine (PX) and Bismark Brown R (BB) in successive batch cultures. To the best of our knowledge, this is the first study on the immobilisation of P. chrysosporium into Ca-alginate beads for its application in dye decolouration.     

Removal of 4-chlorobenzoic acid from spiked hydroponic solution by willow trees (<Emphasis Type="Italic">Salix viminalis</Emphasis>)

Background  

Chlorobenzoic acids (CBA) are intermediate products of the aerobic microbial degradation of PCB and several pesticides. This study explores the feasibility of using basket willows, Salix viminalis, to remove 4-CBA from polluted sites, which also might stimulate PCB degradation.