Browsing by Author "Bastos, Ana Catarina"

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    Biochars in soils: towards the required level of scientific understanding
    (Taylor and Francis, 2016-12-14) Tammeorg, Priit; Bastos, Ana Catarina; Jeffery, Simon; Rees, Frédéric; Kern, Jurgen; Graber, Ellen R.; Ventura, Maurizio; Kibblewhite, Mark G.; Amaro, Antonio; Budai, Alice; Cordovil, Claudia M. D. S.; Domene, Xavier; Gardi, Ciro; Gascó, Gabriel; Horák, Ján; Kammann, Claudia; Kondrlova, Elena; Laird, David; Loureiro, Susana; Martins, Martinho A. S.; Panzacchi, Pietro; Prasad, Munoo; Prodana, Marija; Peregrina Puga, Aline; Ruysschaert, Greet; Sas-Paszt, Lidia; Silva, Flávio C.; Teixeira, Wenceslau Geraldes; Tonon, Giustino; Delle Vedove, Gemini; Zavalloni, Costanza Zavalloni; Glaser, Bruno; Verheijen, Frank G. A.
    Key priorities in biochar research for future guidance of sustainable policy development have been identified by expert assessment within the COST Action TD1107. The current level of scientific understanding (LOSU) regarding the consequences of biochar application to soil were explored. Five broad thematic areas of biochar research were addressed: soil biodiversity and ecotoxicology, soil organic matter and greenhouse gas (GHG) emissions, soil physical properties, nutrient cycles and crop production, and soil remediation. The highest future research priorities regarding biochar’s effects in soils were: functional redundancy within soil microbial communities, bioavailability of biochar’s contaminants to soil biota, soil organic matter stability, GHG emissions, soil formation, soil hydrology, nutrient cycling due to microbial priming as well as altered rhizosphere ecology, and soil pH buffering capacity. Methodological and other constraints to achieve the required LOSU are discussed and options for efficient progress of biochar research and sustainable application to soil are presented.
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    Microbial volatile fingerprints: potential use for soil/water diagnostics and correlation with traditional microbial parameters
    (Cranfield University, 2007) Bastos, Ana Catarina; Magan, Naresh
    This project used an electronic nose (E-nose) system composed of an array of 14 nonspecific conducting polymer sensors for soil and water diagnostics, based on qualitative microbial volatile production patterns. It tested the feasibility of using soil microbial volatile fingerprints for detecting and monitoring changes in microbial activity in three soils, as a response to key environmental factors such as temperature (16, 25, 37°C), water potential (-0.7, -2.8 MPa), and nutrient (glucose and wheat straw) inputs. It also investigated their potential use for atrazine detection when applied to soil at usual field application rates (2.5 ppm) as well as for monitoring its bioremediation using the white-rot fungus Trametes versicolor (R26), for up to 24 weeks. Furthermore, statistical correlations were investigated between soil volatile profiles and traditional microbial parameters for characterising microbial communities and their metabolic activities such as respiration, dehydrogenase (DHA) and laccase (LAC) activities, bacterial and fungal colony counts and fungal community structure under different soil conditions. Finally, this study explored the potential of microbial volatile production patterns for monitoring the activity and differentiation of two Streptomyces species (S. aureofaciens A253 and S. griseus A26) in potable water and in soil, as well as the production of geosmin in both environments. Data in this research has demonstrated that the production of volatile organic compounds (VOC) in soil is likely to arise from microbial metabolism. The E-nose was able to detect variations in the patterns of volatile production from soil according to treatments, functioning as indicators of shifts in microbial activity and community structure. The potential for discrimination between soil types in relation to environmental factors and nutrient addition has been demonstrated for the first time using principle component analysis (PCA). Significant (p<0.05) correlations were also found between soil volatile patterns (through PC1) and traditional soil microbial parameters. The close relationship (r>0.80) between PC1 and soil respiration was particularly relevant, since it indicates that microbial volatile fingerprints, similarly to respiration, respond quickly to changes in soil conditions. The sensor array was also able to detect Streptomyces activity and differentiation as well as discriminate between bacterial species at different concentrations in potable water and in soil. Using this approach, the presence of geosmin was detected in water at 0.5 ppb (below its human odour threshold detection, OTD) and in soil at 100 ppb (OTD not established). This study has, therefore, demonstrated that an E-nose can be employed as a rapid, sensitive, reproducible and non-invasive tool for characterising changes in soil environmental conditions, as well as for monitoring key soil processes such as organic matter decomposition and atrazine degradation. It also suggests that this approach can complement, and perhaps replace, some of these methods for a quick and routine evaluation of the impact of environmental factors on soil microbial communities. Furthermore, this study showed that an E-nose can also be employed for assessing Streptomyces activity and detecting geosmin production at an early stage in water and soil.
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    Representativeness of European biochar research: part II – pot and laboratory studies
    (Taylor & Francis, 2017-06-28) Sakrabani, Ruben; Kern, Jurgen; Mankasingh, Utra; Zavalloni, Costanza; Zanchettin, Giulia; Bastos, Ana Catarina; Tammeorg, Priit; Jeffery, Simon; Glaser, Bruno; Verheijen, Frank G. A.
    Biochar research is extensive and there are many pot and laboratory studies carried out in Europe to investigate the mechanistic understanding that govern its impact on soil processes. A survey was conducted in order to find out how representative these studies under controlled experimental conditions are of actual environmental conditions in Europe and biomass availability and conversion technologies. The survey consisted of various key questions related to types of soil and biochar used, experimental conditions and effects of biochar additions on soil chemical, biological and physical properties. This representativeness study showed that soil texture and soil organic carbon contents used by researchers are well reflected in the current biochar research in Europe (through comparison with published literature), but less so for soil pH and soil type. This study provides scope for future work to complement existing research findings, avoiding unnecessary repetitions and highlighting existing research gaps.
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    Representativeness of European biochar research: Part I–field experiments
    (Taylor & Francis, 2017-06-28) Verheijen, Frank G. A.; Mankasingh, Utra; Penizek, Vit; Panzacchi, Pietro; Glaser, Bruno; Jeffery, Simon; Bastos, Ana Catarina; Tammeorg, Priit; Kern, Jurgen; Zavalloni, Costanza; Zanchettin, Giulia; Sakrabani, Ruben
    A representativeness survey of existing European Biochar field experiments within the Biochar COST Action TD1107 was conducted to gather key information for setting up future experiments and collaborations, and to minimise duplication of efforts amongst European researchers. Woody feedstock biochar, applied without organic or inorganic fertiliser appears over-represented compared to other categories, especially considering the availability of crop residues, manures, and other organic waste streams and the efforts towards achieving a zero waste economy. Fertile arable soils were also over-represented while shallow unfertile soils were under-represented. Many of the latter are likely in agroforestry or forest plantation land use. The most studied theme was crop production. However, other themes that can provide evidence of mechanisms, as well as potential undesired side-effects, were relatively well represented. Biochar use for soil contamination remediation was the least represented theme; further work is needed to identify which specific contaminants, or mixtures of contaminants, have the potential for remediation by different biochars.
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    Trametes versicolor: Potential for atrazine bioremediation in calcareous clay soil, under low water availability conditions.
    (Elsevier, 2009-06) Bastos, Ana Catarina; Magan, Naresh
    This study examined the feasibility of Trametes versicolor to actively degrade atrazine (0.5 μg g−1) in non-sterile calcareous clay soil (Algarve, Portugal) microcosms for up to 24 weeks (20 °C), under low water availability (soil water potentials of −0.7 and −2.8 MPa). Soil respiration, laccase activity, and atrazine quantification by high-performance liquid chromatography (HPLC) were assessed. Respiration was significantly (p < 0.05) enhanced in soil containing the inoculant, particularly in the presence of atrazine, indicating that it remained metabolically active throughout the study. Furthermore, up to 98% and 85% (at −0.7 and −2.8 MPa, respectively) of atrazine was degraded in soil containing both the atrazine and the inoculant, compared to 96% and 50% in soil containing atrazine only. The contribution of T. versicolor to atrazine degradation was only significant (p < 0.005) under the driest soil treatment conditions. The strategies used for enhancing colonisation and biodegradation capabilities of the inoculant, as well as the selection of sawdust as carrier, were thus effective. However, there were no differences (p > 0.05) in quantified laccase activity in soil containing the inoculant and the control. Overall, this study demonstrated that T. versicolor was a strong candidate for atrazine bioremediation in soil with low moisture and organic matter contents, such as that found in semi-arid and Mediterranean-like ecosystems.