DNA stable isotope probing reveals the impact of trophic interactions on bioaugmentation of soils with different pollution histories.

Background: Bioaugmentation is considered a sustainable and cost-effective methodology to recover contaminated environments, but its outcome is highly variable. Predation is a key top-down control mechanism affecting inoculum establishment, however, its effects on this process have received little attention. This study focused on the impact of trophic interactions on bioaugmentation success in two soils with different pollution exposure histories.

Metaproteomic and gene expression analysis of interspecies interactions in a PAH-degrading synthetic microbial consortium constructed with the key microbes of a natural consortium.

Polycyclic Aromatic Hydrocarbons (PAHs) impose adverse effects on the environment and human life. The use of synthetic microbial consortia is promising in bioremediation of contaminated sites with these pollutants. However, the design of consortia taking advantage of natural interactions has been poorly explored.

Assessment of Biological Contribution to Natural Recovery of Anthropized Freshwater Sediments From Argentina: Autochthonous Microbiome Structure and Functional Prediction.

Monitored natural recovery (MNR) is an technique of conventional remediation for the treatment of contaminated sediments that relies on natural processes to reduce the bioavailability or toxicity of contaminants. Metabarcoding and bioinformatics approaches to infer functional prediction were applied in bottom sediments of a tributary drainage channel of Río de La Plata estuary, in order to assess the biological contribution to MNR. Hydrocarbon concentration in water samples and surface sediments was below the detection limit.

Design and evaluation of synthetic bacterial consortia for optimized phenanthrene degradation through the integration of genomics and shotgun proteomics.

Two synthetic bacterial consortia (SC) composed of bacterial strains sp. (AM), (B), sp. (Bc-h and T), sp.

Co-treatment of an oily sludge and aged contaminated soil: permanganate oxidation followed by bioremediation.

The bioremediation of an oily sludge (321 ± 30 mg of polycyclic aromatic hydrocarbons/kg and 13420 ± 1300 mg of aliphatic hydrocarbons/kg) by mixture with contaminated soil (23 ± 2 mg of polycyclic aromatic hydrocarbons/kg and 98 ± 10 mg of aliphatic hydrocarbons/kg) was studied. Furthermore, the effect of oxidative pretreatments (persulfate and permanganate) on the performance of the global process was examined. The treatments reached contamination levels lower than the original residues, indicating the presence of synergic processes between a highly contaminated sludge and soil with a selected hydrocarbon-degrading community.

Assessing interactions, predicting function, and increasing degradation potential of a PAH-degrading bacterial consortium by effect of an inoculant strain.

A natural phenanthrene-degrading consortium CON was inoculated with an exogenous strain Sphingobium sp. (ex Sp. paucimobilis) 20006FA yielding the consortium called I-CON, in order to study ecological interactions into the bacterial community.

Efficiency of surfactant-enhanced bioremediation of aged polycyclic aromatic hydrocarbon-contaminated soil: Link with bioavailability and the dynamics of the bacterial community.

Shifts in the bacterial-community dynamics, bioavailability, and biodegradation of polycyclic aromatic hydrocarbons (PAHs) of chronically contaminated soil were analyzed in Triton X-100-treated microcosms at the critical micelle concentration (T-CMC) and at two sub-CMC doses. Only the sub-CMC-dose microcosms reached sorbed-PAH concentrations significantly lower than the control: 166±32 and 135±4mgkg dry soil versus 266±51mgkg; consequently an increase in high- and low-molecular-weight PAHs biodegradation was observed. After 63days of incubation pyrosequencing data evidenced differences in diversity and composition between the surfactant-modified microcosms and the control, with those with sub-CMC doses containing a predominance of the orders Sphingomonadales, Acidobacteriales, and Gemmatimonadales (groups of known PAHs-degrading capability).

Strategies for oxidation of PAHs in aged contaminated soil by batch reactors.

Polycyclic aromatic hydrocarbons (PAH) are neutral, nonpolar and hydrophobic molecules that tend to sorb onto soil organic matter. Chemical oxidation is a good choice to avoid the limitations of bioremediation. To evaluate the efficiency of different types of oxidation (permanganate, hydrogen peroxide, and persulfate) and activation (heat, alkaline, and iron), batch reactors were prepared.

Assigning ecological roles to the populations belonging to a phenanthrene-degrading bacterial consortium using omic approaches.

The present study describes the behavior of a natural phenanthrene-degrading consortium (CON), a synthetic consortium (constructed with isolated strains from CON) and an isolated strain form CON (Sphingobium sp. AM) in phenanthrene cultures to understand the interactions among the microorganisms present in the natural consortium during phenanthrene degradation as a sole carbon and energy source in liquid cultures. In the contaminant degradation assay, the defined consortium not only achieved a major phenanthrene degradation percentage (> 95%) but also showed a more efficient elimination of the intermediate metabolite.

Monitoring the impact of bioaugmentation with a PAH-degrading strain on different soil microbiomes using pyrosequencing.

The effect of bioaugmentation with Sphingobium sp. AM strain on different soils microbiomes, pristine soil (PS), chronically contaminated soil (IPK) and recently contaminated soil (Phe) and their implications in bioremediation efficiency was studied by focusing on the ecology that drives bacterial communities in response to inoculation. AM strain draft genome codifies genes for metabolism of aromatic and aliphatic hydrocarbons.

Remediation of phenanthrene-contaminated soil by simultaneous persulfate chemical oxidation and biodegradation processes.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous compounds with carcinogenic and/or mutagenic potential. To address the limitations of individual remediation techniques and to achieve better PAH removal efficiencies, the combination of chemical and biological treatments can be used. The degradation of phenanthrene (chosen as a model of PAH) by persulfate in freshly contaminated soil microcosms was studied to assess its impact on the biodegradation process and on soil properties.

Archaeosomes made of Halorubrum tebenquichense total polar lipids: a new source of adjuvancy.

Background: Archaeosomes (ARC), vesicles prepared from total polar lipids (TPL) extracted from selected genera and species from the Archaea domain, elicit both antibody and cell-mediated immunity to the entrapped antigen, as well as efficient cross priming of exogenous antigens, evoking a profound memory response. Screening for unexplored Archaea genus as new sources of adjuvancy, here we report the presence of two new Halorubrum tebenquichense strains isolated from grey crystals (GC) and black mood (BM) strata from a littoral Argentinean Patagonia salt flat. Cytotoxicity, intracellular transit and immune response induced by two subcutaneous (sc) administrations (days 0 and 21) with BSA entrapped in ARC made of TPL either form BM (ARC-BM) and from GC (ARC-GC) at 2% w/w (BSA/lipids), to C3H/HeN mice (25 microg BSA, 1.

Study of the degradation activity and the strategies to promote the bioavailability of phenanthrene by Sphingomonas paucimobilis strain 20006FA.

The present study describes the phenanthrene-degrading activity of Sphingomonas paucimobilis 20006FA and its ability to promote the bioavailability of phenanthrene. S. paucimobilis 20006FA was isolated from a phenanthrene-contaminated soil microcosm.

Dynamics of microbial community during bioremediation of phenanthrene and chromium(VI)-contaminated soil microcosms.

The combined effect of phenanthrene and Cr(VI) on soil microbial activity, community composition and on the efficiency of bioremediation processes has been studied. Biometer flask systems and soil microcosm systems contaminated with 2,000 mg of phenanthrene per kg of dry soil and different Cr(VI) concentrations were investigated. Temperature, soil moisture and oxygen availability were controlled to support bioremediation.

Effect of petrochemical sludge concentrations on microbial communities during soil bioremediation.

Qualitative and quantitative changes of microbial communities in soil microcosms during bioremediation were determined throughout one year. The soil was contaminated with 0%, 2.5%, 5%, 10% (wt/wt) of petrochemical sludge containing polynuclear aromatic hydrocarbons.