Role of Agricultural Management in the Provision of Ecosystem Services in Warm Climate Vineyards: Functional Prediction of Genes Involved in Nutrient Cycling and Carbon Sequestration.

(1) Background: Maintaining soil fertility and crop productivity using natural microbial diversity could be a feasible approach for achieving sustainable development in agriculture. In this study, we compared soils from vineyards under organic and conventional management by predicting functional profiles through metagenomic analysis based on the 16S rRNA gene. (2) Methods: The structure, diversity and predictive functions of soil bacteria related to the biogeochemical cycle of the soil were analyzed, including oxidative and hydrolytic C-cycling enzymes, N-cycling enzymes and P-cycling enzymes.

Resistance and Not Plant Fruit Traits Determine Root-Associated Bacterial Community Composition along a Domestication Gradient in Tomato.

Soil bacterial communities are involved in multiple ecosystem services, key in determining plant productivity. Crop domestication and intensive agricultural practices often disrupt species interactions with unknown consequences for rhizosphere microbiomes. This study evaluates whether variation in plant traits along a domestication gradient determines the composition of root-associated bacterial communities; and whether these changes are related to targeted plant traits (e.

Tomato Domestication Affects Potential Functional Molecular Pathways of Root-Associated Soil Bacteria.

While it has been well evidenced that plant domestication affects the structure of the root-associated microbiome, there is a poor understanding of how domestication-mediated differences between rhizosphere microorganisms functionally affect microbial ecosystem services. In this study, we explore how domestication influenced functional assembly patterns of bacterial communities in the root-associated soil of 27 tomato accessions through a transect of evolution, from plant ancestors to landraces to modern cultivars. Based on molecular analysis, functional profiles were predicted and co-occurrence networks were constructed based on the identification of co-presences of functional units in the tomato root-associated microbiome.

Involvement of the metabolically active bacteria in the organic matter degradation during olive mill waste composting.

RNA-based high-throughput sequencing is a valuable tool in the discernment of the implication of metabolically active bacteria during composting. In this study, "alperujo" composting was used as microbial model for the elucidation of structure-function relationships with physicochemical transformation of the organic matter. DNA and RNA, subsequently retrotranscribed into cDNA, were isolated at the mesophilic, thermophilic and maturation phases.

Long-term no-tillage application increases soil organic carbon, nitrous oxide emissions and faba bean (Vicia faba L.) yields under rain-fed Mediterranean conditions.

The introduction of legumes into crop sequences and the reduction of tillage intensity are both proposed as agronomic practices to mitigate the soil degradation and negative impact of agriculture on the environment. However, the joint effects of these practices on nitrous oxide (NO) and ammonia (NH) emissions from soil remain unclear, particularly concerning semiarid Mediterranean areas. In the frame of a long-term field experiment (23 years), a 2-year study was performed on the faba bean (Vicia faba L.

Spider Communities and Biological Control in Native Habitats Surrounding Greenhouses.

The promotion of native vegetation as a habitat for natural enemies, which could increase their abundance and fitness, is especially useful in highly simplified settings such as Mediterranean greenhouse landscapes. Spiders as generalist predators may also be involved in intra-guild predation. However, the niche complementarity provided by spiders as a group means that increased spider diversity may facilitate complementary control actions.

Long-term effects of contrasting tillage on soil organic carbon, nitrous oxide and ammonia emissions in a Mediterranean Vertisol under different crop sequences.

This 2-year study aimed to verify whether the continuous application of no tillage (NT) for over 20years, in comparison with conventional tillage (CT), affects nitrous oxide (NO) and ammonia (NH) emissions from a Vertisol and, if so, whether such an effect varies with crop sequence (continuous wheat, WW and wheat after faba bean, FW). To shed light on the mechanisms involved in determining N-gas emissions, soil bulk density, water filled pore space (WFPS), some carbon (C) and nitrogen (N) pools, denitrifying enzyme activity (DEA), and nitrous oxide reductase gene abundance (nosZ gene) were also assessed at 0-15 and 15-30cm soil depth. Tillage system had no significant effect on total NH emissions.

Bottom-up effects on herbivore-induced plant defences: a case study based on compositional patterns of rhizosphere microbial communities.

Below-ground soil microorganisms can modulate above-ground plant-insect interactions. It still needs to be determined whether this is a direct effect of single species or an indirect effect of shifts in soil microbial community assemblages. Evaluation of the soil microbiome as a whole is critical for understanding multi-trophic interactions, including those mediated by volatiles involving plants, herbivorous insects, predators/parasitoids and microorganisms.

Impact of agricultural management on bacterial laccase-encoding genes with possible implications for soil carbon storage in semi-arid Mediterranean olive farming.

Background: In this work, we aimed to gain insights into the contribution of soil bacteria to carbon sequestration in Mediterranean habitats. In particular, we aimed to use bacterial laccase-encoding genes as molecular markers for soil organic C cycling. Using rainfed olive farming as an experimental model, we determined the stability and accumulation levels of humic substances and applied these data to bacterial laccase-encoding gene expression and diversity in soils under four different agricultural management systems (bare soils under tillage/no tillage and vegetation cover under chemical/mechanical management).

Molecular tools to understand the bioremediation effect of plants and earthworms on contaminated marine sediments.

A meso-scale pilot plant was set up to test the efficiency of a bioremediation scheme applied to marine sediments contaminated by heavy metals and hydrocarbons. The experiment was implemented for three years in two stages using two remediation agents: plants (Paspalum vaginatum and Tamarix gallica) and earthworms (Eisenia fetida). DNA and RNA-based methodologies were applied to elucidate the dynamics of the bacterial population and were related to improving biological and chemical conditions of the sediments.

Bacterial β-glucosidase function and metabolic activity depend on soil management in semiarid rainfed agriculture.

Genomic and transcriptomic approaches were used to gain insights into the relationship between soil management and bacterial-mediated functions in an olive orchard agroecosystem. Four management practices were assessed in a 30-year trial in a semiarid Mediterranean region. Transcriptional activity of bacterial 16S rRNA genes increased in noncovered soils, indicating higher microbial maintenance requirements to thrive in less favorable environmental conditions.

Bioconversion of wastes from olive oil industries by vermicomposting process using the epigeic earthworm Eisenia andrei.

The present work evaluates the possible bioconversion of wet olive cake by low-cost biostabilization (vermicomposting process). Wet olive cake fresh (WOC), precomposted (WOCP), or mixed with biosolids (WOCB), were vermicomposted for 6 months to obtain organic amendments for agricultural and remediation purposes. The results showed initial differences depending on previous treatment.

Dynamic changes in bacterial community structure and in naphthalene dioxygenase expression in vermicompost-amended PAH-contaminated soils.

The aim of the present study was to explore the potential for using vermicompost from olive-mill waste as an organic amendment for enhanced bioremediation of polycyclic aromatic hydrocarbons (PAHs)-contaminated soils. The focus was to analyse the genetic potential and the naphthalene dioxygenase (NDO) expression of the bacterial communities involved in the degradation of naphthalene, as chemical model for the degradation of PAH. The structure of the metabolically active bacterial population was evidenced in the RNA-based denaturing gradient gel electrophoresis (DGGE) profiles.

Solvent tolerance acquired by Brevibacillus brevis during an olive-waste vermicomposting process.

In this work, a cultivable, Gram-positive, solvent-resistant bacterium was isolated from vermicomposted olive wastes (VOW). The highest 16S rRNA sequence similarity (99%) was found in Brevibacillus brevis. The genome of the isolate, selected for trichloroethylene (TCE)-tolerance, contained a nucleotide sequence encoding a conserved protein domain (ACR_tran) ascribable to the HAE1-RND family.

Metabolic and bacterial diversity in soils historically contaminated by heavy metals and hydrocarbons.

The aim of this study was to characterize soils contaminated by different levels of heavy metals and hydrocarbons (Madonna Dell'Acqua, Pisa, Italy). The soils were chemically and biochemically analysed by measuring the standard chemical properties and some enzyme activities related to microbial activity (dehydrogenase activity) and the soil carbon cycle (total and extracellular beta-glucosidase activities). The metabolic capacities of soil microorganisms to degrade hydrocarbons through catechol 2,3-dioxygenase were also described.

Restoring biochemical activity and bacterial diversity in a trichloroethylene-contaminated soil: the reclamation effect of vermicomposted olive wastes.

Background, Aim, And Scope: In this work, the potential for using olive-mill solid waste as an organic amendment for biochemical and biological restoration of a trichloroethylene-contaminated soil, which has previously been stabilized through vermicomposting processes, has been explored.

Materials And Methods: Trichloroethylene-contaminated water was pumped into soil columns with a layer of vermicompost at 10-cm depth (biobarrier system). The impacts of the trichloroethylene on the microbial community were evaluated by determining: (1) the overall microbial activity (estimated as dehydrogenase activity) and enzyme activities related to the main nutrient cycles (beta-glucosidase, o-diphenoloxidase, phosphatase, urease, and arylsulphatase activities).

Potential use of olive-waste ash from cogeneration plants as a soil amendment.

A greenhouse study was conducted to evaluate the potential use of olive-cake ash as a soil amendment, using pepper (Capsicum annuum, L. cv Italian sweet). Three soils of different pH (acidic, neutral and calcareous) were used.

Development and assessment of an innovative soil-washing process based on the use of cholic acid-derivatives as pollutant-mobilizing agents.

Surfactant-aided soil washing is often proposed for the restoration of aged organic pollutant-contaminated soils. As many of commercial surfactants have been found to be toxic and recalcitrant, the opportunity to use in this process cheap, non-toxic, and biodegradable pollutant-mobilizing agents, such as deoxycholic acid (DA), bovine bile (BB), and the residue resulting from DA extraction from BB (BBR), was studied in this work. A soil historically contaminated by chlorinated anilines and benzenes, thiophenes, and several polycyclic aromatic hydrocarbons was suspended at 15% w/v and washed in water or water amended at 1.

Vermicomposting of winery wastes: a laboratory study.

In Mediterranean countries, millions of tons of wastes from viticulture and winery industries are produced every year. This study describes the ability of the earthworm Eisenia andrei to compost different winery wastes (spent grape marc, vinasse biosolids, lees cakes, and vine shoots) into valuable agricultural products. The evolution of earthworm biomass and enzyme activities was tracked for 16 weeks of vermicomposting, on a laboratory scale.