We have recently signed an agreement with the Centre for Environmental Studies from Vitoria-Gasteiz (Spain) to carry out research on the recovery of degraded and contaminated sites around the city of Vitoria-Gasteiz (Spain). We will focus our research on the design and implementation of phytomanagement strategies to recover soil functionality and the provision of essential soil ecosystem services in degraded sites around the city of Vitoria-Gasteiz.
Carlos Garbisu gave a TEDx talk in Vitoria-Gasteiz, Spain (https://www.youtube.com/watch?v=c4QAo6mWPoE) on the well-known problem of the dissemination of antibiotic resistance among bacteria. He focused his talk on the need to carry out research on Microbial Ecology to better understand the behaviour of bacteria in their natural environment, so that we can then design more effective strategies to fight bacterial pathogens and, alternatively, to learn from the incredible metabolic capacities found in the bacterial world.
One more academic year (2018-2019), we have participated in the Master on Biodiversity, Function and Ecosystem Management (University of the Basque Country, Spain), coordinating a course on rehabilitation and bioremediation of contaminated soils. This year we have (1) paid special attention to microbial speciation processes and (2) discussed the concepts of top-down vs. bottom-up biology, and systems biology. We have also emphasized the need to incorporate a network perspective to studies on soil microbial communities.
Last week we attended the 1st Iberian Ecological Society Meeting. The conference was the kickoff of SIBECOL (Sociedad Ibérica de Ecología) a new scientific society, joining ecologists from Iberian countries, whatever the system or approach they work on. The Asociación Española de Ecología Terrestre (AEET), the Asociación Ibérica de Limnologia (AIL), the Sociedad Española de Etología y Ecología Evolutiva (SEEEE) and the Sociedade Portuguesa de Ecologia (SPECO), as well as a group of Iberian Marine Ecologists, support this initiative.
It was a conference full of inspiring talks that we hope to apply in our future work in SMEG. We also presented two posters related to our work with the dissemination of antibiotic resistance in agriculture and the utilization of arbuscular mycorrhiza as biostimulants.
Authors: Garbisu C, Garaiyurrebaso O, Lanzén A, Álvarez-Rodríguez I, Arana L, Blanco F, Smalla K, Grohmann E, Alkorta I
Title: Mobile genetic elements and antibiotic resistance in mine soil amended with organic wastes
Journal: Science of the Total Environment
Vol: 621 Pages:725-733 Date: 2018
Technosols can be used to rehabilitate degraded land and reuse wastes. Ideally, these newly formed soils should also fulfil the main soil functions. In this study, initially, we characterized the physicochemical and microbial properties of different formulations and their ingredients (i.e., dirt from a waste recovery plant, recycled bentonite, sewage sludge). When these technosols were then used for the rehabilitation of a quarry, the evolution of such properties was monitored for three consecutive years. Physicochemical and microbial properties were compared to those of a reference soil from a nearby forest. Diversity and composition of prokaryotes and eukaryotes were determined using 16S and 18S rRNA amplicon sequencing. Three years after establishment, as much as 78.8% and 63.9% of the prokaryotic and eukaryotic orders, respectively, were shared between the technosols and the reference forest soil. Although technosols initially showed lower values of CO2 emission, compaction and functional diversity (Biolog EcoPlates), at the end of the study these values were similar to those observed in the reference forest soil. It was concluded that the microbiota of the studied technosols resembles that of the nearby forest soil after just three years of establishment.
Livestock manure-derived amendments can be beneficial for agricultural soil quality, as they can increase the content of soil organic matter and nutrients, stimulate microbial activity and biomass, and enhance crop yield. Here, we studied the impact of six different manure-derived amendments, according to the origin (horse manure-derived vs. chicken manure-derived) and type of amendment (fresh vs. composted vs. bokashi), on agricultural soil quality. To this purpose, an experiment was conducted with lettuce plants, paying special attention to amendment-induced changes in soil microbial properties and the abundance and risk of dissemination of antibiotic resistance genes (ARGs) through horizontal gene transfer (HGT). Soils amended with fresh manure showed higher values of microbial biomass and activity. In particular, fresh chicken manure yielded the highest crop yield of lettuce, but also increased the abundance of ARGs considerably. Genes encoding mobile genetic elements (tnpA, intI1) were positively correlated with ARGs, suggesting a risk of dissemination of antibiotic resistance via HGT in agricultural soils, as a result of the application of livestock manure-derived amendments. In order to minimize this risk, we therefore suggest that manure-derived amendments be properly treated and managed prior to their application to agricultural soil.