Browsing by Author "Castro, P.M.L."
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- Bacterial community dynamics in horizontal flow constructed wetlands with different plants for high salinity industrial wastewater polishingPublication . Calheiros, C.S.C.; Teixeira, A.; Pires, C.; Franco, A.R.; Duque, A.F.; Crispim, L.F.C.; Moura, S.C.; Castro, P.M.L.This study is focused on the diversity of bacterial communities from two series of horizontal subsurface flow constructed wetlands (CW) polishing high salinity tannery wastewater. Each series was planted with Arundo donax or Sarcocornia sp. in a substrate composed by expanded clay and sand. Chemical and biochemical oxygen demand removal efficiencies were similar in each series, varying between 58 and 67% (inlet COD 218 ± 28 mg L−1) and 60 and 77% (inlet BOD5 37 ± 6 mg L−1), respectively. High numbers of culturable bacteria were obtained from substrate and root samples – 5.75 × 106-3.95 × 108 CFU g−1 recovered on marine agar and 1.72 × 107-8.46 × 108 CFU g−1 on nutrient agar. Fifty bacterial isolates were retrieved from the CW, related phylogenetically to Firmicutes, Actinobacteria, Bacteroidetes, α-, β-, and γ-Proteobacteria. Changes in the bacterial communities, from roots and substrate of each series, related to the plant species, hydraulic loading rates and along CW operation were examined using denaturating gradient gel electrophoresis (DGGE). The clustering analysis suggested that a diverse and distinct bacterial community inhabits each series, which was related to the type of plant present in each CW.
- Diversity of metallophytes and metal(loid)-tolerant bacterial strains in a portuguese mine for phytotechnologies purposesPublication . Sousa, A. S. S.; Pereira, S. I. A.; Moreira, H.; Cunha, J.; Vila-Viçosa, C.; Castro, P.M.L.Soil contamination with metal(loid)s due to anthropogenic activities, such as mining, is a worldwide issue that affects ecosystem functioning and human health. Efforts are currently made to restore these soils through sustainable and economically strategies. Phytotechnologies stand out as reliable and ecologically sound options, focusing on the use of plants and their associated microorganisms to reclaim contaminated lands and decrease pollutant linkages. These options can also provide economic revenues, integrating soil restoration into the circular economy concept. Mining areas host metallophytes, either excluders or (hyper)accumulators, and plant growth-promoting bacteria (PGPB), adapted to high concentrations of metal(loid)s, that can be used in phytoremediation strategies. The Borralha mine is a deactivated tungsten producer located in the northern Portugal, in which the ending of mineral extraction left several open-air tailings highly contaminated with metal(loid)s, such as Cu, Zn, Cd, As and Pb. This study aimed to assess the most abundant metallophytes and characterize the culturable bacterial community present in Borralha mine tailings for biotechnological purposes. Plant biodiversity was assessed over 1 year period, covering the different seasons. Based on plant taxonomy, a total of 14 plant species were identified, with some species (e.g., Agrostis capillaris, Cytisus striatus, Erica arborea, Pinus pinaster, Rubus ulmifolius, Salix caprea and Sedum arenarium) showing potential to be used in remediation strategies. For soil bacteria characterization, a composite soil sample was collected from vegetated and non-vegetated areas in the tailing zone. A total of 65 bacterial isolates were isolated and characterized genotypically and phenotypically (e.g. metal tolerance and plant growth promoting traits). Several bacterial strains showed potential to be used as bioinoculants in assisted- phytoremediation approaches
- Potential of slurry from intensive dairy cattle farms for paulownia and populus trees, as organic fertilizer: I. effect on productionPublication . Menino, R.; Pereira, S. I. A.; Moreira, H.; Castelo-Branco, A.; Gomes, A. A.; Rodrigues, A.; Cunha, J.; Castro, P.M.L.; Vega, A.; Cardoso, E.; Machado, M. J.; Alves, R.; Cardoso, F.; Lopes, F.; Guedes, R.Intensive dairy cattle breeding have a relevant social and economic impact in portugal, particularly in the northern region. This activity generates a high flow of livestock effluents (slurry), rich in important nutrients for plant growth, which can be introduced into forest production systems. These effluents can provide a good alternative to mineral fertilizers, not only from an economic perspective, but also from the point of view of soil fertility resilience. In the present study, the effect of increasing doses of slurry on tree growth was evaluated in clones of paulownia and populus, as they are genotypes that have a high efficiency in the mobilization of soil nutrients and in the capture of co2 from the atmosphere, as well as high biomass calorific value. To this end, a demonstration field was installed, where the trees were planted with the compasses of: 2.5 x 1.5 m and 2.5 x 0.75 m, respectively for paulownia and for populus. In the field, the following treatments were performed: t0 - no fertilization, either mineral or organic; t1 - amount of slurry equivalent to 85 kg of n ha-1; t2 - amount of slurry equivalent to 170 kg of n ha-1; t3 - amount of slurry equivalent to 340 kg of n ha-1, either with or without inoculation prior to transplantation, with mycorrhizal arbuscular fungi and plant growth-promoting bacteria. Results evidenced a positive effect of the slurry application, both in the diameter at breast height and in total stand height, showing its fertilizing potential which should later be assessed on the ability to constitute an alternative or, simply, a complement to mineral fertilization