Browsing by Author "Castro, P."
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- Beneficial effects of phytomanagement options on soil structural and functional microbial biodiversityPublication . Urra, J.; Epelde, L.; Kidd, P.; Becerril, J.M; Mench, M.; Oustrière, N.; Burges, A.; Castro, P.; Moreira, H. Gomes; Pereira, S.; Garbisu, C.Through the proper phytomanagement of contaminated sites, soil structural and functional microbial biodiversity can be restored, thereby enhancing soil functionality and the provision of vital ecosystem services. Here, a network of sites (located in Spain, France and Portugal) contaminated by metal(loid)s and organic compounds were subjected to a variety of phytomanagement options. Short- and long-term effects on soil microbial communities, as biological indicators of sol quality, were determined for assessing the beneficial effects of applied phytomanagement options on soil functionality and, concomitantly, soil ecosystem services. In particular, a variety of microbial parameters that provide in formation on the biomass (total bacteria and fungi by qPCR). activity (enzyme activities) and diversity (community. level physiological profiles with Biolog Fcoplates ™, 1GS +RNA amplicon sequencing, HT-qPCR of functional genes) were determined in soil samples. In general, phytomanagement treatments led to an improvement in soil functionality. 'The application of organic amendments resulted in a significant increase in soil microbial biomass, activity and diversity. A PCA analysis carried out with all the microbial parameters studied here differentiated the sites and phytomanagement treatments. Similarly, the composition of TU obtained from next generation sequencing data (16S RNA) varied significantly among the different sites and treatments. The data presented here provide insights into the structural and functional diversity of soil microbial communities subjected to phytomanagement. It was concluded that, during phytomanagement, a proper selection of the organic amendments and plants species is essential for the intended reduction in the adverse effects caused by contaminants on soil microbial diversity.
- Ectomycorrhizal fungi as an alternative to the use of chemical fertilisers in nursery production of Pinus pinasterPublication . Sousa, N.; Franco, A.; Oliveira, R.; Castro, P.
- A GAC biofilm reactor for the continuous degradation of 4-chlorophenol: treatment efficiency and microbial analysisPublication . Carvalho, M.; Vasconcelos, I.; Bull, A.; Castro, P.Using a continuous enrichment technique, a bacterial consortium capable of degrading 4-chlorophenol (4-CP) was obtained from the rhizosphere of Phragmites australis. A granular activated carbon (GAC) biofilm reactor was established using this consortium, and the degradation of 4-CP was investigated under continuous flow operation using a feed of 20-50 mg l-1 with a hydraulic residence time of 17 min over a 6-month period. Chloride liberation occurred throughout the operation, and the reactor had 4-CP removal efficiencies of 69-100%. Periods of lower performance were attributed to clogging of the column with biomass and the formation of channels. Subsequently, the immobilized biofilm was subjected to a starvation period of 5 months, after which its degradative capacity was still maintained. The microbial consortium was characterized during the continuous flow experiment and dynamic population changes were observed throughout. One isolate recovered from the biofilm was shown to be capable of degrading 4-CP as a sole carbon and energy source.
- Potential of slurry from intensive dairy cattle farms for Paulownia and Populus trees, as organic fertilizer: I. effect on productionPublication . Menino, R.; Pereira, S. A.; Moreira, H.; Branco, A. C.; Gomes, A. A.; Rodrigues, A.; Cunha, J.; Castro, P.; Vega, A.; Cardoso, E.; Machado, M. J.; Alves, R.; Cardoso, F.; Lopes, F.; Guedes, R.
- Rhizobacterial isolates from the metal hyperaccumulator noccaea caerulescens growing in a Ni enriched soilPublication . Prieto-Fernández, Á.; Moreira, H.; Pereira, S.; Castro, P.; Kidd, P. S.; Rodríguez-Garrido, B.Introduction: Ultramafic (serpentine) outcrops occupy about 1% of the planet and are constituted by igneous or metamorphic rocks with low content in silicon (< 45 % SiO2) more than 70 % of ferromagnesium minerals and usually with high contents of several toxic trace elements (TEs) (Brooks, 1987). The soils developed over these rocks are characterized by deficiency in organic matter and essential nutrients, unfavourable Ca/Mg ratio, high concentrations of potentially phytotoxic trace metals such as Ni, Co and Cr, etc. which make them a harsh environment for the plant growth (serpentine syndrome). The organisms inhabiting these environments developed numerous adaptation mechanisms, as a result, they host a highly valuable biodiversity. The ultramafic flora includes a particular group of plants called hyperaccumulators, which are able to accumulate in their aboveground tissues extremely high concentrations of Ni. The ultramafic outcrops in the NW of Spain host two endemic TE hyperaccumulators: Noccaea caerulescens (J.Presl & C.Presl) and Odontarrhena serpyllifolia (Desf.) Jord. & Fourr. The project Phy2SUDOE (SOE4/P5/E1021), funded by Interreg SUDOE, works on the establishment and maintenance of phytomanagement options, as well as, on the conservation and valorisation of endemic plant and microbial biodiversity in several degraded areas, among them a serpentine quarry in Bandeira (NW Spain). In the frame of this project, this study presents data relative to the hyperaccumulating characteristics of the population of N. caerulescens growing in the Bandeira quarry, as well as, the first results on the diversity of isolates cultivated from the rhizosphere of individuals of this species. Material and methods: An ultramafic area in Bandeira (42o 45´N; 8o 17´W, NW of Spain) was selected for the study (Fig.1). Several individuals of Noccaea caerulescens were collected in the surroundings of a serpentine quarry (Fig. 2). The rhizosphere soil tightly attached to the roots was carefully separated and extracted with 1% sodium hexametaphosphate solution. Dilutions of the soil extract were cultivated in mineral medium amended with 3 mM Ni and with glucose fructose, gluconate, lactate and pyruvate as C sources. 48 bacterial strains were isolated after repeated subculturing. Partial sequencing of the gene 16S rRNA was used for the identification of isolates. Properties related to plant growth promotion (PGP) and mobilization of TE of the rhizobacterial isolates are being studied (e.g. P solubilization, production of organic acids, siderophores and indoleacetic acid (IAA)). Conclusions: The N. caerulescens growing in the serpentine quarry hyperaccumulates Ni and shows capacity of uptake and translocation of Co and Zn. The N. caerulescens studied seems unsuitable as monocrop in phytomining because of its reduced biomass; however, it is interesting to explore its usefulness in intercropping with other hyperaccumulators. Most of the rhizobacterial isolated obtained from N. caerulescens where classified as Pseudarthrobacter, Streptomyces or Mesorhizobium, genera which include known PGP strains. The identified isolates with PGP and TE mobilization capacities may have potential application in phytomining or in other biotechnologies aiming at the mobilization of valuables elements from soils and other TE enriched substrates.