Dados do Trabalho

Título

BIOCHEMICAL AND PGP ACTIVITY OF MICROORGANSIMS FROM THE ROOT-ZONE OF BACCHARIS LINEARIS IN MINE TAILINGS

Resumo

Mine tailings (MTs) are characterised by high metal(loid) contents, acidic pH, poor physical structure, among others, which hinders the plant establishment. However, the application of organic amendments and microorganisms with beneficial traits for plants can assist the phytoremediation. This study evaluates the biological activity of microbial communities from the root-zone of Baccharis linearis naturally present in an abandoned MTs, to assess their potential as biotechnological tools for phytostabilization programs. The root-zone and bulk samples were taken from five B. linearis plants in a MT located in the Mediterranean zone of central Chile. The root-zone comprised the rhizosphere and the closest belowground soil, while the bulk sample consisted of a composited sample obtained random points 2 m apart from each plant. The fluorescein diacetate hydrolysis, arginine ammonification, and the activities of dehydrogenase, β-glucosidase, acid phosphatase and urease were measured. The community-level physiological profile (CLPP) and the average well-colour development (AWCD) were assessed with the MicroRespTM system. Bacterial plant growth-promoting (PGP) traits and colony-forming units (CFU) were evaluated by qualitative and microbiological methods, respectively. Physicochemical properties of the MT were also assessed. The CFU was 50 times higher in the root-zone compared with the bulk samples. Enzyme activities and AWCD were significantly higher in the root-zone than in bulk samples. CLPP showed that individual microbial utilization of C sources was higher in the root-zone except for carboxylic acids. Five isolated bacteria strains were obtained from the root-zone, which showed PGP traits such as P solubilisation, N acquisition, indole acetic acid production, among others. Results suggest that microbial communities from the root-zone of B. linearis represent a potential biotechnological tool for further ecological management of mine tailings

Palavras-chave

Enzyme activities, Rhizosphere, Mining, PGPR

Instituição financiadora

This research was funded by the FONDECYT project 3210752 of HA