Microbial community evolution during restoration of stream Morales (Matanza-Riachuelo basin, Marcos Paz Municipality)

AGNELLO, A.C.; DEL PANNO, M.T.; DE CABO, L.; TRENTINI, A.G.; MARCONI, P.L.

Montevideo

Encuentro; X Encuentro Latinoamericano y del Caribe de Biotecnología Agropecuaria y XI Simposio REDBIO Argentina; 2019

REDBIO, INIA

Stream Morales has near its coast, in Marcos Paz Municipality, a landfill (7 ha) that has been used as dumping ground during, almost, 30 years. During 2017, the waste disposal was organized and the landfill was closed. In order to restore the landfill, the wastes were removed and the landfill was covered with crushed stones (March 2017-March 2018). The restoration processes were ended in December 2018 with the assembly of a biocorridor of native flora in the Matanza-Riachuelo basin. Trees, shrubs and herbaceous plants were distributed in 3 ha according to their environmental requirements. Four months later, the vegetal ground cover reached up to 92% (initially was only 3% plant cover). The objective of the present work was to study the diversity of microbial communities developed in the rhizosphere of different plant species used to restore the ex-landfill. Soil samples were obtained from 1) a control area without a story of dumping activities, 2) a control area in the dumping site that was not restored with vegetation and 3) the rhizosphere of vegetated restored area at the beginning of the intervention process and four months later. Microbial diversity of soil and rhizosphere samples was studied by DNA extraction, PCR amplification of 16S rRNA hypervariable regions and separation of the PCR products by denaturing gradient gel electrophoresis (DGGE).Clustering analysis using the UPGMA algorithm and the Jaccard coefficient revealed a shift in microbial communities of the rhizosphere of restored areas over time. After four months, bacterial communities of vegetated areas became more similar to the microbiome of the control soil that was never used as landfill. The results of this first monitoring indicate that the development of a plant cover could be an auspicious initial step to restore bacterial communities of the ex-landfill.