Fresh biochar application provokes a reduction of nitrate which is unexplained by conventional mechanisms.

Soil-applied biochar has been reported to possess the potential to mitigate nitrate leaching and thus, exert beneficial effects beyond carbon sequestration. The main objective of the present study is to confirm if a pine gasification biochar that has proven able to decrease soil-soluble nitrate in previous research can indeed exert such an effect and to determine by which mechanism. For this purpose, lysimeters containing soil-biochar mixtures at 0, 12 and 50 t biochar ha-1 were investigated in two different scenarios: a fresh biochar scenario consisting of fresh biochar and a fallow-managed soil, and an aged biochar scenario with a 6-yr naturally aged biochar in a crop-managed soil. Soil columns were assessed under a mimicked Mediterranean ambient within a greenhouse setting during an 8-mo period which included a barley crop cycle. A set of parameters related to nitrogen cycling, and particularly to mechanisms that could directly or indirectly explain nitrate content reduction (i.e., sorption, leaching, microbially-mediated processes, volatilisation, plant uptake, and ecotoxicological effects), were assessed. Specific measurements included soil solution and leachate ionic composition, microbial biomass and activity, greenhouse gas (GHG) emissions, N and O isotopic composition of nitrate, crop yield and quality, and ecotoxicological endpoints, among others. Nitrate content reduction in soil solution was verified for the fresh biochar scenario in both 12 and 50 t ha-1 treatments and was coupled to a significant reduction of chloride, sodium, calcium and magnesium. This effect was noticed only after eight months of biochar application thus suggesting a time-dependent process. All other mechanisms tested being discarded, the formation of an organo-mineral coating emerges as a plausible explanation for the ionic content decrease.

Correlation between mutational status and survival and second cancer risk assessment in patients with gastrointestinal stromal tumors: a population-based study.

BACKGROUND: Gastrointestinal stromal tumors are sarcomas of the digestive tract characterized by mutations mainly located in the c-KIT or in the platelet-derived growth factor receptor (PDGFR)-alpha genes. Mutations in the BRAF gene have also been described. Our purpose is to define the distribution of c-KIT, PDGFR and BRAF mutations in a population-based cohort of gastrointestinal stromal tumors (GIST) patients and correlate them with anatomical site, risk classification and survival. In addition, as most of the GIST patients have a long survival, second cancers are frequently diagnosed in them. We performed a second primary cancer risk assessment. METHODS: Our analysis was based on data from Tarragona and Girona Cancer Registries. We identified all GIST diagnosed from 1996 to 2006 and performed a mutational analysis of those in which paraffin-embedded tissue was obtained. Observed (OS) and relative survival (RS) were calculated according to risk classifications and mutational status. Multivariate analysis of variables for observed survival and was also done. RESULTS: A total of 132 GIST cases were found and we analyzed mutations in 108 cases. We obtained 53.7% of mutations in exon 11 and 7.4% in exon 9 of c-KIT gene; 12% in exon 18 and 1.9% in exon 12 of PDGFR gene and 25% of cases were wild type GIST. Patients with mutations in exon 11 of the c-KIT gene had a 5-year OS and RS of 59.6% and 66.3%, respectively. Patients with mutations in exon 18 of the PDGFR gene had a 5-year OS and RS of 84.6% and 89.7%. In multivariate analysis, only age and risk group achieved statistical significance for observed survival. GIST patients had an increased risk of second cancer with a hazard ratio of 2.47. CONCLUSIONS: This population-based study shows a spectrum of mutations in the c-KIT and PDGFR genes in GIST patients similar to that previously published. The OS and RS of GIST with the exon 18 PDGFR gene mutation could indicate that this subgroup of patients may be less aggressive and have a good prognosis, although less sensitive to treatment at recurrence. In our study, GIST patients have an increased risk of developing a second neoplasm.

Consequences of warming and resource quality on the stoichiometry and nutrient cycling of a stream shredder.

As a result of climate change, streams are warming and their runoff has been decreasing in most temperate areas. These changes can affect consumers directly by increasing their metabolic rates and modifying their physiology and indirectly by changing the quality of the resources on which organisms depend. In this study, a common stream detritivore (Echinogammarus berilloni Catta) was reared at two temperatures (15 and 20°C) and fed Populus nigra L. leaves that had been conditioned either in an intermittent or permanent reach to evaluate the effects of resource quality and increased temperatures on detritivore performance, stoichiometry and nutrient cycling. The lower quality (i.e., lower protein, soluble carbohydrates and higher C:P and N:P ratios) of leaves conditioned in pools resulted in compensatory feeding and lower nutrient retention capacity by E. berilloni. This effect was especially marked for phosphorus, which was unexpected based on predictions of ecological stoichiometry. When individuals were fed pool-conditioned leaves at warmer temperatures, their growth rates were higher, but consumers exhibited less efficient assimilation and higher mortality. Furthermore, the shifts to lower C:P ratios and higher lipid concentrations in shredder body tissues suggest that structural molecules such as phospholipids are preserved over other energetic C-rich macromolecules such as carbohydrates. These effects on consumer physiology and metabolism were further translated into feces and excreta nutrient ratios. Overall, our results show that the effects of reduced leaf quality on detritivore nutrient retention were more severe at higher temperatures because the shredders were not able to offset their increased metabolism with increased consumption or more efficient digestion when fed pool-conditioned leaves. Consequently, the synergistic effects of impaired food quality and increased temperatures might not only affect the physiology and survival of detritivores but also extend to other trophic compartments through detritivore-mediated nutrient cycling.

Quantitative structure-activity relationship (QSAR) prediction of (eco)toxicity of short aliphatic protic ionic liquids.

Ionic liquids (ILs) are considered as a group of very promising compounds due to their excellent properties (practical non-volatility, high thermal stability and very good and diverse solving capacity). The ILs have a good prospect of replacing traditional organic solvents in vast variety of applications. However, the complete information on their environmental impact is still not available. There is also an enormous number of possible combinations of anions and cations which can form ILs, the fact that requires a method allowing the prediction of toxicity of existing and potential ILs. In this study, a group contribution QSAR model has been used in order to predict the (eco)toxicity of protic and aprotic ILs for five tests (Microtox®, Pseudokirchneriella subcapitata and Lemna minor growth inhibition test, and Acetylcholinestherase inhibition and Cell viability assay with IPC-81 cells). The predicted and experimental toxicity are well correlated. A prediction of EC50 for these (eco)toxicity tests has also been made for eight representatives of the new family of short aliphatic protic ILs, whose toxicity has not been determined experimentally to date. The QSAR model applied in this study can allow the selection of potentially less toxic ILs amongst the existing ones (e.g. in the case of aprotic ILs), but it can also be very helpful in directing the synthesis efforts toward developing new "greener" ILs respectful with the environment (e.g. short aliphatic protic ILs).

Enfermedad neumocócica invasiva en la Comunitat Valenciana. Seis años de vigilancia (2007-2012) / Invasive pneumococcal disease in the Community of Valencia. Six years of surveillance (2007-2012)

INTRODUCCIÓN: La introducción de las vacunas conjugadas antineumocócicas ha supuesto un cambio en la epidemiología de la enfermedad neumocócica invasiva (ENI). El objetivo de nuestro estudio ha sido describir la evolución de la ENI en la Comunidad Valenciana durante el periodo 2007-2012. MATERIAL Y MÉTODOS: Estudio descriptivo longitudinal retrospectivo de ENI en la Comunidad Valenciana durante el periodo 2007-2012. Las fuentes de información utilizadas han sido el sistema de Análisis de la Vigilancia Epidemiológica (AVE) y la Red Microbiológica Valenciana (RedMIVA) de la Conselleria de Sanitat. RESULTADOS: La incidencia de ENI ha disminuido entre 2007 y 2012 en todos los grupos de edad, mayoritariamente en menores de 5 años, pasando de 30,5 a 12,3 casos por 105 habitantes (p < 0,001). La neumonía constituye la principal forma de presentación de la enfermedad, con disminución de sus cifras de 6,9 a 4,1 casos por 105 (p < 0,001). Se ha observado una reducción progresiva no significativa de la proporción de casos por serotipos contenidos en la vacuna heptavalente (PCV7), principalmente en menores de 5 años, del 26 al 12% (p = 0,23). Los casos por serotipos adicionales de la vacuna conjugada 13-valente (1, 3, 5, 6A, 7F y 19A) también muestran tendencia descendente, principalmente en menores de 5 años vacunados (52,6% vs 14,3%; p = 0,03), mientras que se incrementa significativamente la proporción de casos por serotipos no vacunales, del 42,3 al 56,7% en población general (p = 0,002), y del 47,4 al 78,6% en menores de 5 años vacunados (p = 0,08). CONCLUSIONES: Los resultados de este estudio muestran una reducción de la incidencia de ENI, con disminución de la proporción de casos producidos por serotipos vacunales e incremento de la proporción de los no vacunales. La vigilancia epidemiológica resulta necesaria para monitorizar la evolución de la enfermedad

INTROCUCTION: The introduction of conjugated anti-pneumonia vaccines has led to a change in the epidemiology of Invasive Pneumococcal Disease (IPD). The aim of this study is to describe the trends in IPD in the Community of Valencia during the period 2007-2012. Material and methods: A retrospective, descriptive and longitudinal study was conducted on IPD in the Community of Valencia during the period 2007-2012, The information sources used were the Epidemiological Surveillance Analysis (Análisis de la Vigilancia Epidemiológica (AVE)) and the Valencian Microbiology Net York (Red Microbiológica Valenciana (RedMIVA)) of the Valencia Health Department. Results: The incidence of IPD decreased between 2007 and 2012 in all age groups, mainly in the under 5 year-olds, dropping from 30.5 cases to 12.3 cases per 105 inhabitants (p < .001). Pneumonia was the principal presentation of the disease, with a decrease in its rates from 6.9 to 4.1 cases per 105 inhabitants (p < .001). A gradual, non-significant, reduction from 26% to 12% (p = .23) was observed in the proportion of cases due to the serotypes contained in the heptavalent vaccine (PCV7), mainly in the under 5 year-olds. The cases due to additional serotypes in 13-valent conjugated vaccine (1, 3, 5, 6A, 7F and 19A) also showed a decreasing trend, mainly in vaccinated under 5 year-olds (52.6% vs 14.3%; p = .03), while the cases due to non-vaccine serotypes significantly increased from 42.3% to 56.7% in the general population (p = .002), and from 47.4% to 78.6% in vaccinated under 5 year-olds (p = .08). Conclusions: The results of this study show a reduction in the incidence of IPD, with a decrease in the proportion of cases produced by vaccine serotypes, and an increase in the proportion of those not vaccinated. Epidemiological Surveillance is necessary to monitor the trends in the disease (AU)

[Invasive pneumococcal disease in the Community of Valencia. Six years of surveillance (2007-2012)]. / Enfermedad neumocócica invasiva en la Comunitat Valenciana. Seis años de vigilancia (2007-2012).

INTRODUCTION: The introduction of conjugated anti-pneumonia vaccines has led to a change in the epidemiology of Invasive Pneumococcal Disease (IPD). The aim of this study is to describe the trends in IPD in the Community of Valencia during the period 2007-2012. MATERIAL AND METHODS: A retrospective, descriptive and longitudinal study was conducted on IPD in the Community of Valencia during the period 2007-2012, The information sources used were the Epidemiological Surveillance Analysis (Análisis de la Vigilancia Epidemiológica (AVE)) and the Valencian Microbiology Network (Red Microbiológica Valenciana (RedMIVA)) of the Valencia Health Department. RESULTS: The incidence of IPD decreased between 2007 and 2012 in all age groups, mainly in the under 5 year-olds, dropping from 30.5 cases to 12.3 cases per 10(5) inhabitants (p< .001). Pneumonia was the principal presentation of the disease, with a decrease in its rates from 6.9 to 4.1 cases per 10(5) inhabitants (p< .001). A gradual, non-significant, reduction from 26% to 12% (p=.23) was observed in the proportion of cases due to the serotypes contained in the heptavalent vaccine (PCV7), mainly in the under 5 year-olds. The cases due to additional serotypes in 13-valent conjugated vaccine (1, 3, 5, 6A, 7F and 19A) also showed a decreasing trend, mainly in vaccinated under 5 year-olds (52.6% vs 14.3%; p=.03), while the cases due to non-vaccine serotypes significantly increased from 42.3% to 56.7% in the general population (p=.002), and from 47.4% to 78.6% in vaccinated under 5 year-olds (p=.08). CONCLUSIONS: The results of this study show a reduction in the incidence of IPD, with a decrease in the proportion of cases produced by vaccine serotypes, and an increase in the proportion of those not vaccinated. Epidemiological Surveillance is necessary to monitor the trends in the disease.

CD8-positive peripheral T-cell lymphoma with aberrant expression of CD20 and concurrent in situ follicular lymphoma.

A case of a 78-year-old woman with a CD8-positive peripheral T-cell lymphoma with aberrant expression of CD20 associated with follicular lymphoma in situ (FLIS) is reported. The neoplasm presented initially as cutaneous macules, papules, plaques and nodules. A skin biopsy was performed and the diagnosis of peripheral T-cell lymphoma (PTCl) with aberrant expression of CD20 was made. The staging procedures included an excisional inguinal lymph node biopsy that showed findings similar to those of the previous diagnosis. In addition, FLIS was identified. The clinicopathologic features of PTCLs with aberrant CD20 expression involving the skin as well as this uncommon association are reviewed.

A comparative study of the terrestrial ecotoxicity of selected protic and aprotic ionic liquids.

Ionic liquids (ILs) are a fairly new and very promising group of compounds with a vast variety of possible structures and uses. They are considered to be potentially "green", but their impact on the environment tends to be neglected or not studied enough, especially when it comes to terrestrial ecotoxicity, where there are very few studies performed to date. This work presents a comparative study of the terrestrial ecotoxicity of selected representatives of two ILs groups: a new family of protic ILs (derived from aliphatic amines and organic acids) and some frequently used aprotic ILs (substituted imidazolium and piridinium chlorides). Toxicity of the ILs towards three terrestrial plant species (Allium cepa, Lolium perenne and Raphanus sativus) and soil microorganisms involved in carbon and nitrogen transformation was analyzed. Protic ILs have shown no toxic effect in most of the tests performed. The EC50 values for aprotic ILs are various orders of magnitude lower than the ones for protic ILs in all of the tests. The most toxic ILs are the most complex ones in both of the analyzed groups. Protic ILs seem to have a potential for biodegradation in soil, while aprotic ILs exhibit inhibitory effects towards the carbon transforming microbiota. These findings indicate that protic ILs can be considered as less toxic and safer for the terrestrial environment than the aprotic ILs.

(Eco)toxicity and biodegradability of selected protic and aprotic ionic liquids.

Ionic liquids (ILs) are a promising group of compounds with a large variety of possible structures and uses. They are considered as a potential "green" replacement for traditional volatile organic solvents, but their impact on the environment is often neglected or not studied enough. In the present study, selected representatives of two ILs groups were analyzed: a new family of protic ILs (derived from aliphatic amines and organic acids) and some frequently used aprotic ILs (substituted imidazolium and piridinium chlorides). The aquatic toxicity (test organisms Vibrio fischeri, Pseudokirchneriella subcapitata and Lemna minor) and biodegradability tests were carried out. The additional tests with enzyme (acetylcholinesterase) and leukemia rat cells (IPC-81) provided more in-depth evaluation of toxicity. In our comparative hazard assessment protic ILs have EC50 values >100 mg L(-1) in all of the tests performed, except in the case of three representatives toward Lemna minor. They also show good biodegradability rates. The EC50 values for aprotic ILs are various orders of magnitude lower than the ones for protic ILs in most of the tests and they show a lower biodegradability potential. These findings indicate that protic ILs can be considered as environmentally safer alternatives for more toxic ILs and organic solvents.

Ecotoxicity of Cr, Cd, and Pb on two Mediterranean soils.

Three potentially toxic elements [chromium (Cr), lead (Pb), and cadmium (Cd)] were tested to assess their effects on two soils of different properties and origin. The soils were a granitic soil (Haplic Arenosol), which meets the requirements of OECD ecotoxicity testing, and a calcareous soil (Calcaric Regosol) with properties often found in the Mediterranean areas. The metal concentrations used ranged from 0.001 to 5,000 mg kg(-1) soil. The effects on soil microbial activity and community composition (respirometry and polymerase chain reaction-denaturing gradient gel electrophoresis analysis), as well as the effects on plant germination and elongation (Lactuca sativa), were assessed. The toxicity of the soil water extracts was also evaluated by the growth inhibition of algal populations (Pseudokirschneriella subcapitata). Cr showed the highest level of toxicity to soil organisms in the assays performed because this element remains in soil as anionic form and is less retained by the soil solid matrix than Cd and Pb. The lowest observed-adverse effect level for Cr ranged from approximately 0.1 mg kg(-1) [substrate induced respiration (SIR) test for the granitic soil] to 10 mg kg(-1) (basal respiration and SIR tests for the calcareous soil). For Pb (SIR) and Cd (SIR and alga tests), these levels were approximately 100 mg kg(-1). Germination and algal tests showed higher sensitivity in Regosol soil than in Arenosol soil for Cr due to differences in the bioavailability between the soils. In the cases or areas where alkaline soils are abundant, these should also be considered in laboratory ecotoxicity testing to avoid underestimation of ecotoxicological risks.

The exposition of a calcareous Mediterranean soil to toxic concentrations of Cr, Cd and Pb produces changes in the microbiota mainly related to differential metal bioavailability.

The involvement of the bacterial community of an agricultural Mediterranean calcareous soil in relation to several heavy metals has been studied in microcosms under controlled laboratory conditions. Soil samples were artificially polluted with Cr(VI), Cd(II) and Pb(II) at concentrations ranging from 0.1 to 5000 mg kg(-1) and incubated along 28 d. The lowest concentrations with significant effects in soil respirometry were 10 mg kg(-1) Cr and 1000 mg kg(-1) Cd and Pb. However, only treatments showing more than 40% inhibition of respirometric activity led to significant changes in bacterial composition, as indicated by PCR-DGGE analyses. Presumable Cr- and Cd-resistant bacteria were detected in polluted microcosms, but development of the microbiota was severely impaired at the highest amendments of both metals. Results also showed that bioavailability is an important factor determining the impact of the heavy metals assayed, and even an inverted potential toxicity ranking could be achieved if their soluble fraction is considered instead of the total concentration. Moreover, multiresistant bacteria were isolated from Cr-polluted soil microcosms, some of them showing the capacity to reduce Cr(VI) concentrations between 26% and 84% of the initial value. Potentially useful strains for bioremediation were related to Arthrobacter crystallopoietes, Stenotrophomonas maltophilia and several species of Bacillus.

Relationship between pollutant content and ecotoxicity of sewage sludges from Spanish wastewater treatment plants.

Chemical and ecotoxicological properties of 28 sewage sludge samples from Spanish wastewater treatment plants were studied in order to assess their suitability for agricultural purposes. Sludge samples were classified into five categories according to specific treatment processes in terms of digestion (aerobic/anaerobic) and drying (mechanical/thermal). Composted samples, as indicative of the most refined process, were also considered. Sludges were subjected to physical-chemical characterization, being the sludge stabilization degree respirometrically assessed. The concentrations of seven metals (Cd, Cr, Cu, Pb, Zn, Ni, Hg) and organic substances (phenolic compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polychlorinated naphthalenes, polybrominated diphenyl ethers, and perfluorinated compounds) were determined. Finally, two ecotoxicological tests were performed: i) Microtox® toxicity test with Vibrio fischeri, and ii) root elongation test with Allium cepa, Lolium perenne and Raphanus sativus seeds. Significant differences were found in the following parameters: dry matter, electrical conductivity, nitrogen, organic matter and its stability, phytotoxicity and ecotoxicity, depending on the sludge treatment. In turn, no significant differences were found between categories in the concentrations of most metals and organic pollutants, with the exception of free phenolic compounds. Furthermore, no correlation between total heavy metal burden and ecotoxicity was observed. However, a good correlation was found between phenolic compounds and most ecotoxicological tests. These results suggest that sludge stability (conditioned by sludge treatment) might have a greater influence on sludge ecotoxicity than the pollutant load. Composting was identified as the treatment resulting in the lowest toxicity.

Terrestrial ecotoxicity of short aliphatic protic ionic liquids.

A study of the ecotoxicity of different short aliphatic protic ionic liquids (PILs) on terrestrial organisms was conducted. Tests performed within the present study include those assessing the effects of PILs on soil microbial functions (carbon and nitrogen mineralization) and terrestrial plants. The results show that the nominal lowest-observed-adverse-effect concentration (LOAEC) values were 5,000 mg/kg (dry soil) for the plant test in two species (Lolium perenne, Allium cepa), 1,000 mg/kg (dry soil) for the plant test in one species (Raphanus sativus), and 10,000 mg/kg (dry soil) for carbon and nitrogen microbial transformation tests (all concentrations are nominal). Most of the median effective concentration values (EC50) were above 1,000 mg/kg (dry soil). Based on the obtained results, these compounds can be described as nontoxic for soil microbiota and the analyzed plants, and potentially biodegradable in soils, as can be deduced from the respirometric experiment. The toxicity rises with the increase of complexity of the PILs molecule (branch and length of aliphatic chain) among the three PILs analyzed.

Ecotoxicity of chlorophenolic compounds depending on soil characteristics.

Three chlorophenolic compounds (2-chlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol) were tested to assess their effects on two soils with different properties: a granitic soil (Haplic Arenosol) and a calcareous one (Calcaric Regosol). Different concentrations of the pollutants (ranging from 0.001 to 10,000 mg kg(-1) soil, d.w.) were assayed for their effects on soil microbial activity and composition, using manometric respirometry and PCR-DGGE analysis, respectively. Other ecotoxicity tests such as Lactuca sativa seedling growth in the contaminated soils and algal growth inhibition (Pseudokirschneriella subcapitata) in their water extracts were done. The behaviour of the pollutants in the soils with respect to biodegradability and volatilization was also investigated. In the Haplic Arenosol, volatilization is the main process affecting 2-chlorophenol. Degradation and fixation of this compound in the soil matrix are favored in the Calcaric Regosol. This is the least toxic pollutant assayed. For 2,4,6-trichlorophenol, the soil pH is a critical parameter in the toxicity assays due to the neutral pKa of the compound. It is toxic in the soil microbial activity assay, but some recovery of the biotic processes can be observed, particularly in the Calcaric Regosol. This compound is more toxic in the Haplic Arenosol than in the Calcaric Regosol. Pentachlorophenol is ionized in both soils due to its low pKa, increasing its water solubility. It is highly toxic to the soil microbiota, thus inhibiting respiration, biodegradation and other biotic dissipation processes. Plant and alga tests, were more sensitive than soil microbial tests, except for PCP. The microbial populations tend to show changes at lower concentrations than the microbial activity. Some soil types (abundant in the Mediterranean area), with alkaline pH and fine textures could show higher level of ecotoxicity for ionizable organic pollutants than the soil type recommended by the OECD in ecotoxicity testing.

Impact of chlorophenols on microbiota of an unpolluted acidic soil: microbial resistance and biodegradation.

The impact of 2-monochlorophenol (MCP), 2,4,6-trichlorophenol (TCP) and pentachlorophenol (PCP) on the microbial community of an acidic forest soil was studied under controlled laboratory conditions by spiking microcosms with the pollutants at concentrations ranging from 0.1 to 5000 mg kg(-1). A decrease in the cumulative respirometric values and changes in the bacterial and fungal community composition were detected at 1000 mg MCP kg(-1), 100 mg TCP kg(-1) and 100 and 1000 mg PCP kg(-1). However, drastic effects on the microbial community were revealed only at higher concentrations of MCP and TCP, although the toxicity of PCP was expected to be stronger. The acidic condition of the soil presumably reduces bioavailability of PCP, leading to less pronounced effects than the other pollutants. This finding highlights the consideration of pollutant bioavailability in each environment to adequately assess contamination effects. Twenty-two different chlorophenol-resistant and potentially degrading microorganisms were isolated from highly polluted microcosms. The most resistant isolates were related to Burkholderia arboris, Bacillus circulans, Paenibacillus taichungensis, Luteibacter rhizovicina and Janibacter melonis. These isolates also showed the capacity to reduce the concentration of TCP or PCP between 15% and 35% after 5 days of incubation (initial concentration of 50 mg L(-1)). The isolate related to B. circulans is an atypical case of a member of the Firmicutes group for which chlorophenol-degrading capacities have been described.

The microbiota of an unpolluted calcareous soil faces up chlorophenols: Evidences of resistant strains with potential for bioremediation.

To highlight the effects of a variety of chlorophenols (CP) in relation to the response of an indigenous bacterial community, an agricultural Mediterranean calcareous soil has been studied in microcosms incubated under controlled laboratory conditions. Soil samples were artificially polluted with 2-monochlorophenol (MCP), 2,4,6-trichlorophenol (TCP) and pentachlorophenol (PCP), at concentrations ranging from 0.1 up to 5000 mg kg(-1). Both activity and composition of the microbial community were assessed during several weeks, respectively, by respirometric methods and PCR-DGGE analysis of extracted DNA and RNA. Significant decreases in soil respirometric values and changes in the bacterial community composition were observed at concentrations above 1000 mg kg(-1) MCP and TCP, and above 100 mg kg(-1) PCP. However, the persistence of several active bacterial populations in soil microcosms contaminated with high concentration of CP, as indicated by DGGE fingerprints, suggested the capacity of these native bacteria to survive in the presence of the pollutants, even without a previous adaptation or contact with them. The isolation of potential CP degraders was attempted by culture plating from microcosms incubated with high CP concentrations. Twenty-three different isolates were screened for their resistance to TCP and PCP. The most resistant isolates were identified as Kocuria palustris, Lysobacter gummosus, Bacillus sp. and Pseudomonas putida, according to 16S rRNA gene homology. In addition, these four isolates also showed the capacity to reduce the concentration of TCP and PCP from 15% to 30% after 5d of incubation in laboratory assays (initial pollutant concentration of 50 mg L(-1)). Isolate ITP29, which could be a novel species of Bacillus, has been revealed as the first known member in this bacterial group with potential for CP bioremediation applications, usually wide-spread in the soil natural communities, which has not been reported to date as a CP degrader.

Ecotoxicological tests assessment of soils polluted by chromium (VI) or pentachlorophenol.

Carbon mineralisation and plant germination and growth (Lactuca sativa seeds) tests have been performed in two soils of different properties, experimentally spiked with pentachlorophenol (PCP) or Cr (VI), in concentrations between 0.001 and 1000 mg kg(-1). The evaluation has been done considering the following parameters of carbon transformation test: soil cumulative basal respiration after 14 days incubation, substrate induced respiration after 12 h of glucose addition, and, in the plant germination and growth test: number of germinated seeds, root elongation and total biomass produced. The most sensitive assay found in our work has been carbon mineralisation test, from which the lowest toxic concentrations were obtained (especially substrate induced respiration test). In the plant germination and growth test, the measurement of root elongation has shown the best sensitiveness, followed by plant biomass and seed germination numbers. Regarding the contaminants, the highest toxicity, considering the minimum concentration with toxic effect, has been found in PCP (0.01 mg kg(-1)) in C mineralisation test in the granitic soil. For Cr, the minimum concentration with toxic effect has been 0.1 mg kg(-1), also in the C mineralisation test and the granitic soil. The granitic soil has shown more vulnerability to the pollutants assayed in the respiration test, whereas the calcareous soil has shown more vulnerability in the plant germination and growth test.

Effects of the agronomic use of olive oil mill wastewater: field experiment.

The aim of this study is to assess the effects of olive oil wastewater application on soils. The work consists of field application of the waste at different rates (30, 180, 360 m(3) ha(-1)). Increasing rates of waste enhance the soil fertility due to P, organic matter and N. However, temporary nitrogen immobilisation, increase in salinity values and in phenolic compounds concentrations, both sorbed and soluble forms, have also been observed. Phenolic compounds have been rapidly biodegraded in soil.