Browsing by Author "Pereira, S.I.A."
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- Endophytic culturable bacteria colonizing Lavandula dentata L. plants: Isolation, characterization and evaluation of their plant growth-promoting activitiesPublication . Pereira, S.I.A.; Monteiro, Cristina M.; Vega, A. L.; Castro, Paula M. L.Aromatic plants such as lavender are stirring the attention of many researchers due to their content in bioactive secondary metabolites that can be used in traditional medicine. However, information regarding naturally occurring lavender associated bacterial endophytes (BE) is limited. To the best of our knowledge, this is the first study which aims to assess the phylogenetic diversity of the culturable endophytic bacteria of Lavandula dentata cultivated under organic management and to evaluate their potential as plant growth promoting (PGP) agents. BE were grouped by random amplified polymorphic DNA and identified by 16S ribosomal RNA gene sequencing. Endophytes were further characterized for the ability to produce several PGP substances, like ammonia, siderophores, indol-3-acetic acid, and hydrogen cyanide and for the ability to solubilize phosphate. Plant cell-wall degrading enzymes were also determined. Densities of BE were higher in roots (log 6.39 CFU g−1 fresh weight) than in shoots (log 5.56 CFU g−1 fresh weight). Phylogenetic analysis showed that BE were affiliated to two major groups: -Proteobacteria (50%) and Firmicutes (31.6%) and a small part belonged to - (7.9%) and -Proteobacteria (10.5%), being Pseudomonas and Bacillus the most highly represented genera. Higher bacterial diversity was found in the lavender roots, with endophytes belonging to 6 different genera (Pseudomonas, Variovorax, Rhizobium, Caulobacter, Bacillus and Paenibacillus), than in shoots where only 3 genera (Bacillus, Pseudomonas and Xanthomonas) were found. Overall, BE showed ability to produce extracellular enzymes and multiple PGP traits, suggesting their potential use as efficient bioinoculants in sustainable cultivation of medicinal and aromatic plants.
- Impact of heavy metals and metalloids on soil microorganisms of mining areasPublication . Moreira, H.; Pereira, S.I.A.; Castro, P. M. L.Soil is a non-renewable resource that plays a key role in sustaining life. However, soils’ degradation has increased in the last decades due anthropogenic activities leading to the loss of their functions and ecosystems services. Mining operations are one of the majors soil disruptors and are associated with a broad range of environmental negative impacts, including the decline of soils’ quality over large areas. The release of hazardous compounds, such as heavy metals and metalloids, during the extraction and processing of mineral ores leads to long-term contamination and hampers the survival of soil-associated microorganisms. The microbial diversity and activity in such polluted soils is disturbed causing negative cross-effects in the ecosystems, as soil microorganisms play a significant role in nutrient recycling and in biogeochemical cycles. Although microbial redundancy may occur and some microorganisms reveal resistance or tolerance mechanisms, the simplification of microbial communities and the subsequent decrease in their activity can lead to the failure of general soil functions. In this review the effects of mining-generated heavy metals and metalloids on soil microbial activities and composition are discussed. Soil microbiological and biochemical properties such as biomass, enzyme activity, respiration and communities’ shifts commonly found in these areas are addressed and the general impact of these microbial modifications in the soil functions is underlined.
- Sustainable solutions for mediterranean agroecosystems through enhanced soil microbial diversityPublication . Epelde, L.; Anitua, A.; Lavín, J.L.; Garbisu, C.; Prieto-Fernández, Á.; Monterroso Martínez, M. C.; Rodríguez-Garrido, B.; Cepeda, C. Trasar; González-Prieto, S.; Cortet, J.; Delcourt, N.; Kadiri, N.; Vergnes, A.; Roussel, S.; Blayac, T.; Lavaine, E.; Boularbah, A; Benidire, L.; Balghiti, F. Z. El; Allani, M.; Soufi, S.; T., Bettaieb; Sahli, A.; Semida, W. M.; Abd El-Mageed, T. A.; Abdulfattah, M.A.; Alves, R.; Oliveira, M.; Santos, C.; Tassi, E.; Bretzel, F.; D'Acqui, L. P.; Pini, R.; di Lonardo, S.; Cortez, J.; Cardoso, E; Moreira, H.; Pereira, S.I.A.; Castro, P. M. L.