Fate of sulfadiazine administered to pigs and its quantitative effect on the dynamics of bacterial resistance genes in manure and manured soil

The veterinary antibiotic sulfadiazine (SDZ), labelled by ¹⁴C, was administered to pigs to follow the fate of the drug and its metabolites in manure and manure-amended soil, and to investigate the dynamics of drug effects on resistance genes and bacterial communities. In the manure sampled over 10 days, more than 96% of the drug was found as parent compound or metabolites N-acetyl-SDZ and 4-hydroxy-SDZ. While the manure was stored the concentration of SDZ increased by 42% due to deacetylation of the metabolite N-acetyl-SDZ, whereas the minor metabolite 4-hydroxy-SDZ kept constant. In the soil the extractable amounts of the compounds decreased exponentially to less than 1 mg kg^?1 within 11 days after manure amendment. The abundances of SDZ resistance genes sul1 and sul2 were determined by qPCR relative to 16S rRNA genes in total DNA from manure and manure-amended soil. In manure both genes increased exponentially in copy number during the first 60 days of storage, suggesting preferential growth of resistant populations. However, the abundance of sul1 and sul2 decreased below 10^?5 copies per 16S rRNA gene after 175 days. With manure high amounts of sul1 and sul2 were introduced into the soil which were reduced by more than 10 times within 24 days. Thereafter, sul1 was stably maintained in soil, while sul2 further decreased between day 60 and day 165. A mathematical model was developed that could well explain the time course of sul gene abundance by considering the cost of sul genes, horizontal gene transfer, and selection of the resistant populations in the presence of SDZ. Modelling revealed a selective effect of SDZ on sul2 even at low concentrations down to 0.15 mg kg^?1 soil. Bacterial community profiles of manure and manure-amended soil were distinct, indicating that bacteria introduced with manure do not become prominent in soil. The composition of the bacterial community in manure constantly changed during storage, but mainly during the first 10 days. Profiles of soil bacterial communities revealed only a transient perturbation by manure containing SDZ.     

Recommended urban storm water infiltration devices for different types of run-off under varying hydrogeological conditions

Background, aim, and scope  The decentralised near-natural infiltration of storm water in urban areas over a long-term period can cause local pollution of soil, seepage water and groundwater due to heavy metals (e.g. Pb, Zn, Cu), polycyclic aromatic hydrocarbons (PAH), petroleum hydrocarbons and readily soluble salts, which compounds are partly classified as hazardous. The aim of this paper is to present a recommendation matrix for suitable storm water infiltration devices. The scope is limited to eight different run-off types and two different infiltration devices (swales and trenches with three different trench-filling materials) under two different hydrogeological conditions (high adsorbing soil with low permeability, low adsorbing soil with high permeability). The examined run-off types are sub-divided as follows: run-off from unpaved areas (gardens, grassed areas, cultivated land); green roofs, aluminium roofs; roofs without zinc gutters and down-pipes; roofs with zinc gutters and down-pipes; copper roofs; zinc roofs and trafficked areas (cycle and pedestrian ways, yards, car parks and residential roads). The recommendation matrix should assist decision-makers such as city planners, architects and private house builders. Materials and methods  The potential for storm water infiltration to pollute soil, seepage water and groundwater is investigated with long-term 3-D numerical water flow and chemical transport modelling in unsaturated and saturated zones over 50 years, which were already presented by Zimmermann et al. (Water Sci Technol 51(2):11–19, 2005). The recommendation is based on a comparison between modelling results and several guideline values prepared by several German authorities. The evaluation process leads to four hazard levels regarding the impact on topsoil (i.e. first 20 cm of the soil), on seepage water (1 m below the infiltration device) and on groundwater (at the unsaturated–saturated boundary). Results  The recommendation matrix consists of 56 individual statements. Relating to dissolved organic substances like phenanthrene and fluoranthene, the infiltration of trafficked areas run-off is critical. The infiltration of metalliferous run-off has a high hazard accumulation potential. Here the storm water infiltration via sub-ground of low permeability and high adsorbing soil material is critical for seepage water in any case; the infiltration of zinc roofs run-off via trench infiltration devices is even critical for groundwater at 4 m depth. Sub-ground of low permeability and high adsorbing soil material has a lower potential hazard in terms of storm water infiltration from roof run-off. The storm water infiltration via swales effects a very large accumulation of heavy metals in the topsoil. The storm water infiltration via trenches leads to the accumulation of hazardous substances in the deeper sub-ground, particularly where the trench-filling material has low adsorbing capacity and high permeability. Discussion  The transferability of the results to other sites depends particularly on the hydrogeological conditions. Before using the recommendation matrix, details of the hydrogeological conditions should be collected. The long-term simulation process is simplified by several impact factors such as non-constant rainfall, soils heterogeneity, macro-porous flow, particle-bounded transport and microbiological decomposition. Conclusions  Based on the scale of risks to soils, seepage water and groundwater, the matrix should be used in the selection of the roof construction materials and appropriate storm water infiltration devices so that the environmental risks can be minimised. If the sub-ground has a high permeability and low adsorption capacities, the infiltration of metalliferous roof run-off water is, in general, not advisable without putting treatment facilities in place upstream. Thus, architects need to realise that the choice of a suitable infiltration device depends, on the one hand, on the type of run-off and, on the other hand, on the hydrogeological condition and the building materials. Recommendations and perspectives  Replacement of the topsoil in swale infiltration devices is recommended because, in particular, heavy metal (zinc) in run-off from roofs with zinc gutters and down-pipes accumulates in the soil matrix. The replacement interval depends on the hydrogeological conditions and, for this run-off example, lies between 10 and 20 years. If infiltration is essential, constructing special treatment facilities upstream can be an alternative. The existing numerical model could be adapted to suit other site-specific materials and be enhanced regarding several complex impact factors.     

Cu‐, Zn‐ und Cd‐Aneignungsvermögen von zwei Spinatgenotypen in Abhängigkeit von der P‐Versorgung und Wurzelexsudation

Cu, Zn, and Cd acquisition by two spinach cultivars depending on P nutrition and root exudation Within a spectrum of 11 spinach cultivars (cvs) differences in the Cu, Zn, and Cd contents of shoots had been noticed. The aim of this study was therefore to analyze in more detail the acquisition of Cu, Zn, and Cd by the most differing cultivars (Tabu and Monnopa) in dependence on P nutrition. The plants were grown in a low phosphorus Luvisol (pH 6.3; total contents Cu: 89, Zn: 297, Cd: 2.4 mg kg^—1) with two phosphorus levels in pots under natural conditions. For the determination of inflow, root length/shoot weight ratio and of the Cu, Zn, and Cd concentration in the soil solution (rhizosphere) plants were harvested 26 and 40 days after sowing. Root exudation of organic acids of the two cvs was measured 35 days after growing in quartz sand with different P supply. Both cultivars responded to P fertilizer by doubling their shoot weight. With increased P supply (0.68—0.77% P in shoot‐DM) both cultivars showed similar heavy metal contents in the shoot resulting from similar root length/shoot weight ratios (RSR) and net uptake rates of the three elements as well as the same element concentrations in the rhizosphere soil solution. Under P deficiency, however, cv. Tabu (0.52% P in shoot‐DM) showed in comparison with cv. Monnopa (0.48% P) higher Cu, Zn, and Cd contents of shoots although its RSR was smaller than that of cv. Monnopa. However, the inflow for Cu was higher and for Zn and Cd significantly higher compared with cv. Monnopa. This result of cv. Tabu corresponded with higher concentrations of Cu, Zn, and Cd of its rhizosphere soil solution, and its higher exudation rates of oxalate, citrate, and malate (3.9; 1.0; 0.7 nmol cm^—1 h^—1). The corresponding values for cv. Monnopa were: 1.7; 0.3; 0.4 nmol cm^—1 h^—1. The mobilization of Cu, Zn, and Cd by the excreted organic acids seems to be responsible for the higher Cu, Zn, and Cd inflow of cv. Tabu.     

Stable isotopes infer the value of Australia’s coastal vegetated ecosystems from fisheries

Wild capture fisheries provide substantial input to the global economy through employment and revenue. The coastal zone is especially productive, accounting for just 7% of the total area of the ocean, but supporting an estimated 50% of the world's fisheries. Vegetated coastal ecosystems—seagrass meadows, tidal marshes and mangrove forests—are widely cited as providing nutritional input that underpin coastal fisheries production; however, quantitative evidence of this relationship is scarce. Using Australia as a case study, we synthesized fisheries stable isotope data to estimate nutritional input derived from coastal vegetated ecosystems and combined these “proportional contribution” estimates with total annual catch data from commercial fisheries to determine species‐specific dollar values for coastal vegetated ecosystems. Based on the data from 96 commercially important fish species across Australian states (total landings 14 × 10⁶ tonnes pa), we provide a conservative estimate that Australia's coastal vegetated ecosystems contribute at least 78 million AUD per year to the fisheries economy. Two thirds of this contribution came from tidal marshes and seagrasses that were both equally valued at 31.5 million AUD per year (39.4%) followed by mangroves at 14.9 million AUD per year (18.6%). The highest dollar values of coastal ecosystems originated from eastern king prawn (Melicertus plebejus) and giant mud crab (Scylla serrata). This study demonstrates the substantial economic value supported by Australia's coastal vegetated ecosystems through commercial fisheries harvest. These estimates create further impetus to conserve and restore coastal wetlands and maintain their support of coastal fisheries into the future.     

Novel lysimeter techniques — a basis for the improved investigation of water,gas, and solute transport in soils

For many years lysimeters have been proven to be effective tools in assessing and predicting the effects of current land use and future land use changes in catchment areas on both water and solute balances. Although due to the diverse aspects of mass transport modelling, many different types of lysimeters exist, water and solute balances are by no means fully understood, especially in post‐mining areas. To tackle this problem, a new piece of equipment has been developed which enables the actual weight of a lysimeter to be precisely measured. The newly designed device, which has been used for one of the experiments described in this paper, permits the weighing of for example a 2 m³ lysimeter vessel with an accuracy down to 30 g. The second newly developed appliance presented here is the GAMS (Gas‐Migration‐Simulator). Basically comparable to a lysimeter, the difference is that the GAMS allows the detailed investigation of soil‐gas migration processes and their dependence on parameters like the diffusion coefficient and the gas permeability of the soil, alterations of the groundwater level and on various external influences such as changes of the actual meteorological conditions. These two newly developed techniques are described in this paper, and their respective suitability is demonstrated on the basis of data sets recorded during initial experiments.     

Relationship between soil organic matter and micropores in a long-term experiment at Ultuna,Sweden

Our study showed that long‒term addition of organic matter to a fine textured soil (36.5% clay, 41% silt, 22.5% sand) resulted in an increase of both macro‒ and microporosity in the top soil layer. In terms of changes of the absolute pore volume, macropores were of main importance. However, in relative terms, the increase of microporosity was comparable to that of macroporosity (75% and 90%). Changes in porosity upon different organic matter levels had a marginal effect on the water storage capacity. Micropores with diameters in the range of 1—30 μm were highly significantly correlated to soil organic matter characteristics showing that there is a non‒uniform distribution in relation to pores. Mechanisms leading to disproportionally high concentrations of soil organic matter in relation to micropores are discussed.     

Structure-specific detection of plant cuticle bound residues of chlorothalonil by ELISA

Monoclonal antibodies (mAb) against the main photo-addition products of chlorothalonil with olefinic compounds of plant cuticles were produced. An indirect competitive enzyme-linked immunosorbent assay (ELISA) was developed for the detection of free and bound chlorothalonil and its derivatives. For the characterization of the binding properties of the mAb, derivatives of chlorothalonil (simulating structures of cuticle bound residues) were synthesized. The cross-reactivities of these products were determined by ELISA. The test system was employed to detect bound residues of chlorothalonil in enzymatically isolated tomato cuticles, which had been spiked with methanolic solutions of the compound, irradiated by simulated sunlight and extracted. The use of isolated cuticles allows work to be carried out with authentic material without disturbance by metabolic processes. © 1999 Society of Chemical Industry     

Temporal synchrony of Thaumetopoea processionea egg hatch and Quercus robur budburst

Field observations on egg hatch of Thaumetopoea processionea suggest that temporal asynchrony with Quercus robur budburst leads to starvation, retarded neonate development and mortality. However, T. processionea neonates are generally well adapted to variable between-tree and within-tree budburst phenology reflecting the species’ close bond to its host. They are able to withstand starvation periods of up to 3 weeks while searching extensively for suitable buds to feed on. Feeding and movements of young larvae frequently occur during daytime presumably taking advantage of higher day temperatures when night temperatures are below the species’ thermal threshold. Due to the specific adaptations, we assume precise temporal synchrony to play a minor role regarding its influences on T. processionea population dynamics. However, if hatching precedes budburst for more than 2–3 weeks, temporal asynchrony may become a significant mortality factor for the neonates particularly when other adverse events (e.g. unfavourable weather conditions) during that period are involved. Therefore, future studies should try to reveal further details of this interaction and focus on the impact of global warming on T. processionea—oak budburst synchronisation.     

Prediction of deoxynivalenol and zearalenone in winter wheat grain in a maize-free crop rotation based on cultivar susceptibility and meteorological factors

Journal of Plant Diseases and Protection - Grains of the three differentially Fusarium-susceptible winter wheat cultivars “Ritmo” (highly susceptible), “Inspiration”...