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Kolbas A.,University of Bordeaux 1 | Mench M.,University of Bordeaux 1 | Herzig R.,Phytotech Foundation | Nehnevajova E.,Free University of Berlin | Bes C.M.,University of Bordeaux 1
International Journal of Phytoremediation | Year: 2011

Use of sunflower (Helianthus annuus L.) for Cu phytoextraction and oilseed production on Cu-contaminated topsoils was investigated in a field trial at a former wood preservation site. Six commercial cultivars and two mutant lines were cultivated in plots with and without the addition of compost (5% w/w) and dolomitic limestone (0.2% w/w). Total soil Cu ranged from 163 to 1170 mg kg -1. In soil solutions, Cu concentration varied between 0.16-0.93 mg L -1. The amendment increased soil pH, reduced Cu exposure and promoted sunflower growth. Stem length, shoot and capitulum biomasses, seed yield, and shoot and leaf Cu concentrations were measured. At low total soil Cu, shoot Cu mineralomass was higher in commercial cultivars, i.e., Salut, Energic, and Countri, whereas competition and shading affected morphological traits of mutants. Based on shoot yield (7 Mg DW ha -1) and Cu concentration, the highest removal was 59 g Cu ha -1. At high total soil Cu, shoot Cu mineralomass peaked for mutants (e.g., 52 g Cu ha -1 for Mutant 1 line) and cultivars Energic and Countri. Energic seed yield (3.9 Mg air-DW ha -1) would be sufficient to produce oil. Phenotype traits and shoot Cu removal depended on sunflower types and Cu exposure. © Taylor & Francis Group, LLC.

Kolbas A.,French National Institute for Agricultural Research | Kolbas A.,Brest State University | Kidd P.,CSIC - National Institute of Agrobiological Sciences | Guinberteau J.,French National Institute for Agricultural Research | And 3 more authors.
Environmental Science and Pollution Research | Year: 2015

Endophytic bacteria from roots and crude seed extracts of a Cu-tolerant population of Agrostis capillaris were inoculated to a sunflower metal-tolerant mutant line, and their influence on Cu tolerance and phytoextraction was assessed using a Cu-contaminated soil series. Ten endophytic bacterial strains isolated from surface-sterilized A. capillaris roots were mixed to prepare the root endophyte inoculant (RE). In parallel, surface-sterilized seeds of A. capillaris were crushed in MgSO4 to prepare a crude seed extract containing seed endophytes (SE). An aliquot of this seed extract was filtered at 0.2 μm to obtain a bacterial cell-free seed extract (SEF). After surface sterilization, germinated sunflower seeds were separately treated with one of five modalities: no treatment (C), immersion in MgSO4 (CMg) or SEF solutions and inoculation with RE or SE. All plants were cultivated on a Cu-contaminated soil series (13–1020 mg Cu kg−1). Cultivable RE strains were mostly members of the Pseudomonas genera, and one strain was closely related to Labrys sp. The cultivable SE strains belonged mainly to the Bacillus genera and some members of the Rhodococcus genera. The treatment effects depended on the soil Cu concentration. Both SE and SEF plants had a higher Cu tolerance in the 13–517 mg Cu kg−1 soil range as reflected by increased shoot and root DW yields compared to control plants. This was accompanied by a slight decrease in shoot Cu concentration and increase in root Cu concentration. Shoot and root DW yields were more promoted by SE than SEF in the 13–114 mg Cu kg−1 soil range, which could reflect the influence of seed-located bacterial endophytes. At intermediate soil Cu (416–818 mg Cu kg−1 soil), the RE and CMg plants had lower shoot Cu concentrations than the control, SE and SEF plants. At high total soil Cu (617–1020 mg Cu kg−1), root DW yield of RE plants slightly increased and their root Cu concentration rose by up to 1.9-fold. In terms of phytoextraction efficiency, shoot Cu removal was increased for sunflower plants inoculated with crude and bacterial cell-free seed extracts by 1.3- to 2.2-fold in the 13–416 mg Cu kg−1 soil range. Such increase was mainly driven by an enhanced shoot DW yield. The number and distribution of endophytic bacteria in the harvested sunflower tissues must be further examined. © 2015, Springer-Verlag Berlin Heidelberg.

Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: KBBE.2010.3.5-01 | Award Amount: 3.95M | Year: 2011

Gentle remediation options (g.r.o.) include various (mostly plant based) approaches to remediate trace element contaminated soils at low cost and without significant negative effects for the environment. Although g.r.o. comprise very innovative and efficient technologies, they are still not widely used as practical site solution due to several reasons of hindrance for applying g.r.o. as practical solution. Greenland is bringing gentle remediation options (phytoremediation, in situ stabilisation) into practical application and to solve the final problems comprising still major reasons of hindrance. The major objectives are: test the remediation efficiency and success in pilot field case studies develop a toolkit to quantify the remediation progress and targets (no total, but bioavailable trace element fractions) test different technologies of biomass valorisation (incineration, gasification, biodiesel production, etc.) develop a decision support tool publish a best practice guide Greenland has defined two groups of end users: 1) companies that will offer gentle remediation options commercially (including the treatment of metal-rich biomass) - these group is part of the project consortium 2) stakeholders (including environmental agencies) that will decide for gentle remediation options - these are not part of the project consortium but of the advisory board. The main task of the advisory board is to take part at 4 Greenland meetings (kick off, 2 midterm, final meeting) to give feedback on the project progress. The members of the advisory board should especially consider if their requirements are met (e.g. do we provide all needed information to allow the future stakeholders deciding for gentle remediation options). The travel costs will be covered by the consoritum.

Herzig R.,Phytotech Foundation | Nehnevajova E.,Phytotech Foundation | Nehnevajova E.,Ecole Polytechnique Federale de Lausanne | Nehnevajova E.,Free University of Berlin | And 6 more authors.
International Journal of Phytoremediation | Year: 2014

Phytoextraction with somaclonal variants of tobacco and sunflower mutant lines (non-GMs) with enhanced metal uptake and tolerance can be a sustainable alternative to conventional destructive decontamination methods, especially for stripping bioavailable zinc excess in topsoil. The overall results of a 5-year time series experiment at field scale in north-eastern Switzerland confirm that the labile Zn pool in soil can be lowered by 45-70%, whereas subplots without phytoextraction treatment maintained labile Zn concentrations. In 2011, the phytoextraction experiment site was enlarged by a factor of 3, and the labile 0.1 M NaNO3 extractable Zn concentration in the soil was reduced up to 58% one period after harvest. A Mass Balance Analysis confirmed soil Zn decontamination in line with plant Zn uptake. The plants partially take Zn from the non-labile pool of the total. The sustainability of Zn phytoextraction in subplots that no longer exceed the Swiss trigger value is now assessed over time. In contrary to the phytoextraction of total soil Zn which needs a long cleaning up time, the bioavailable Zn stripping is feasible within a few years period. © 2014 Copyright Taylor and Francis Group, LLC.

Kolbas A.,French National Institute for Agricultural Research | Kolbas A.,University of Bordeaux 1 | Kolbas A.,Brest State University | Marchand L.,French National Institute for Agricultural Research | And 5 more authors.
Plant and Soil | Year: 2013

Background and aims: The potential use of a metal-tolerant sunflower mutant line for both biomonitoring and phytoremediating a Cu-contaminated soil series was investigated. Methods: The soil series (21-1,170 mg Cu kg-1) was sampled in field plots at control and wood preservation sites. Sunflowers were cultivated 1 month in potted soils under controlled conditions. Results: pH and dissolved organic matter influenced Cu concentration in the soil pore water. Leaf chlorophyll content and root growth decreased as Cu exposure rose. Their EC10 values corresponded to 104 and 118 μg Cu L-1 in the soil pore water, 138 and 155 mg Cu kg-1 for total soil Cu, and 16-18 mg Cu kg-1 DW shoot. Biomass of plant organs as well as leaf area, length and asymmetry were well correlated with Cu exposure, contrary to the maximum stem height and leaf water content. Conclusions: Physiological parameters were more sensitive to soil Cu exposure than the morphological ones. Bioconcentration and translocation factors and distribution of mineral masses for Cu highlighted this mutant as a secondary Cu accumulator. Free Cu2+ concentration in soil pore water best predicted Cu phytoavailability. The usefulness of this sunflower mutant line for biomonitoring and Cu phytoextraction was discussed. © 2013 Springer Science+Business Media Dordrecht.

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