Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 84
Filtrar
1.
Mar Pollut Bull ; 202: 116275, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38564821

RESUMEN

Mesopelagic water from the deep Eastern Mediterranean Sea (EMS) was collected under disrupted (REPRESS) or undisturbed (HP) pressure conditions and was acclimated to oil (OIL) or dispersed-oil (DISPOIL) under in situ pressure and temperature (10 MPa, 14 °C). Decompression resulted in oil-acclimatised microbial communities of lower diversity despite the restoration of in situ pressure conditions during the 1-week incubation. Further biodiversity loss was observed when oil-acclimatised communities were transferred to ONR7 medium to facilitate the isolation of oil-degrading bacteria. Microbial diversity loss impacted the degradation of recalcitrant oil compounds, especially PAHs, as low-abundance taxa, linked with PAH degradation, were outcompeted in the enrichment process. Thalassomonas, Pseudoalteromonas, Halomonas and Alcanivorax were enriched in ONR7 under all experimental conditions. No effect of dispersant application on the microbial community structure was identified. A. venustensis was isolated under all tested conditions suggesting a potential key role of this species in hydrocarbons removal in the deep EMS.


Asunto(s)
Biodiversidad , Microbiota , Petróleo , Mar Mediterráneo , Microbiota/efectos de los fármacos , Biodegradación Ambiental , Hidrocarburos Policíclicos Aromáticos/análisis , Bacterias , Medios de Cultivo , Contaminantes Químicos del Agua , Agua de Mar/microbiología , Agua de Mar/química , Presión
2.
Int J Phytoremediation ; 26(6): 964-974, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38038643

RESUMEN

Phytoremediation, including bacteria-assisted phytoremediation, presents a promising technology for treating shooting range soils contaminated with toxic metalloids. In this study, a pot experiment was performed using the halophyte Tamarix smyrnensis and soil collected from a shooting range and artificially spiked at two different antimonite (Sb(III)) concentrations (50 mg/kg and 250 mg/kg) with the aim to explore the Sb phytoremediation of the halophyte. The effect of salt (0.3%) and Mn addition (300 ppm) on its remediation capacity was also investigated. Moreover, the root endophytic community of the halophyte was found able to remove Sb(III) and was periodically inoculated to the plants. The consortium application increased the Sb bioavailable fraction in the soil and enhanced the Sb accumulation in root and aerial parts (up to 50% and 55% respectively at high Sb(III) concentration) compared to the uninoculated plants. Moreover, the presence of Mn increased the translocation factor (21% increase for inoculated and 46% increase for uninoculated plants) while lower TF was observed at high Sb concentrations (0,2 and 0,07 was the lowest value at low and high Sb treatments respectively). The addition of salt, Mn and root endophytic bacteria aided the halophyte to cope with elevated Sb concentrations. The total chlorophyll concentration was higher in inoculated plants compared to the uninoculated ones in all treatments, implying the positive effects of endophytic inoculation. The halophyte T. smyrnensis with the aid of endophytic community presents a promising alternative for remediating shooting range soils especially in areas impacted by salinity.


The halophyte T. smyrnensis presents a promising alternative for remediating shooting range soilsThe application of endophytic bacteria improved the Sb phytoremediation capacity of T. smyrnensisThe halophyte T. smyrnensis can be used for Sb phytoextraction in soils impacted by salinity.


Asunto(s)
Contaminantes del Suelo , Tamaricaceae , Plantas Tolerantes a la Sal , Biodegradación Ambiental , Bacterias , Cloruro de Sodio/farmacología , Suelo , Contaminantes del Suelo/análisis
3.
Mar Drugs ; 21(12)2023 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-38132933

RESUMEN

Marine sponges are highly efficient in removing organic pollutants and their cultivation, adjacent to fish farms, is increasingly considered as a strategy for improving seawater quality. Moreover, these invertebrates produce a plethora of bioactive metabolites, which could translate into an extra profit for the aquaculture sector. Here, we investigated the chemical profile and bioactivity of two Mediterranean species (i.e., Agelas oroides and Sarcotragus foetidus) and we assessed whether cultivated sponges differed substantially from their wild counterparts. Metabolomic analysis of crude sponge extracts revealed species-specific chemical patterns, with A. oroides and S. foetidus dominated by alkaloids and lipids, respectively. More importantly, farmed and wild explants of each species demonstrated similar chemical fingerprints, with the majority of the metabolites showing modest differences on a sponge mass-normalized basis. Furthermore, farmed sponge extracts presented similar or slightly lower antibacterial activity against methicillin-resistant Staphylococcus aureus, compared to the extracts resulting from wild sponges. Anticancer assays against human colorectal carcinoma cells (HCT-116) revealed marginally active extracts from both wild and farmed S. foetidus populations. Our study highlights that, besides mitigating organic pollution in fish aquaculture, sponge farming can serve as a valuable resource of biomolecules, with promising potential in pharmaceutical and biomedical applications.


Asunto(s)
Agelas , Antiinfecciosos , Staphylococcus aureus Resistente a Meticilina , Poríferos , Animales , Humanos , Poríferos/química , Agelas/química , Staphylococcus aureus Resistente a Meticilina/metabolismo , Antiinfecciosos/farmacología , Antibacterianos/farmacología , Antibacterianos/metabolismo
4.
Water Res ; 246: 120687, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37801984

RESUMEN

Marine plastics, with their negative effects on marine life and the human health, have been recently recognized as a new niche for the colonization and development of marine biofilms. Members of the colonizing communities could possess the potential for plastic biodegradation. Thus, there is an urgent need to characterize these complex and geographically variable communities and elucidate the functionalities. In this work, we characterize the fungal and bacterial colonizers of 5 types of plastic films (High Density Polyethylene, Low Density Polyethylene, Polypropylene, Polystyrene and Polyethylene Terepthalate) over the course of a 242-day incubation in the south-eastern Mediterranean and relate them to the chemical changes observed on the surface of the samples via ATR-FTIR. The 16s rRNA and ITS2 ribosomal regions of the plastisphere communities were sequenced on four time points (35, 152, 202 and 242 days). The selection of the time points was dictated by the occurrence of a severe storm which removed biological fouling from the surface of the samples and initiated a second colonization period. The bacterial communities, dominated by Proteobacteria and Bacteroidetes, were the most variable and diverse. Fungal communities, characterized mainly by the presence of Ascomycota, were not significantly affected by the storm. Neither bacterial nor fungal community structure were related to the polymer type acting as substrate, while the surface of the plastic samples underwent weathering of oscillating degrees with time. This work examines the long-term development of Mediterranean epiplastic biofilms and is the first to examine how primary colonization influences the microbial community re-attachment and succession as a response to extreme weather events. Finally, it is one of the few studies to examine fungal communities, despite them containing putative plastic degraders.


Asunto(s)
Clima Extremo , Plásticos , Humanos , Agua de Mar/microbiología , ARN Ribosómico 16S , Polipropilenos , Polietileno , Bacterias/metabolismo
5.
Sci Rep ; 13(1): 16716, 2023 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-37794127

RESUMEN

The colloidal stability of air nanobubbles (NBs) was studied at different temperatures (0-30 °C) and in the presence of sulfates, typically found in mining effluents, in a wide range of Na2SO4 concentrations (0.001 to 1 M), along with the effect of surfactants (sodium dodecyl sulfate), chloride salts (NaCl), and acid/base reagents at a pH range from 4 to 9. Using a nanobubble generator based on hydrodynamic cavitation, 1.2 × 108 bubbles/mL with a typical radius of 84.66 ± 7.88 nm were generated in deionized water. Multiple evidence is provided to prove their presence in suspension, including the Tyndall effect, dynamic light scattering, and nanoparticle size analysis. Zeta potential measurements revealed that NBs are negatively charged even after two months (from - 19.48 ± 1.89 to - 10.13 ± 1.71 mV), suggesting that their stability is due to the negative charge on their surface. NBs were found to be more stable in alkaline solutions compared to acidic ones. Further, low amounts of both chloride and sulfate dissolved salts led to a reduction of the size of NBs. However, when high amounts of dissolved salts are present, NBs are more likely to coalesce, and their size to be increased. Finally, the investigation of the stability of air NBs at low temperatures revealed a non-monotonic relationship between temperature and NBs upon considering water self-ionization and ion mobility. This research aims to open a new frontier towards the application of the highly innovative NBs technology on the treatment of mining, mineral, and metal processing effluents, which are challenging aqueous solutions containing chloride and sulfate species.

6.
Sci Total Environ ; 899: 165601, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37478929

RESUMEN

Besides the release of organic matter from uneaten feed and fish excreta, a considerable amount of deleterious chemicals may also end up into the marine environment from intensive aquaculture. A fraction of these pollutants remains freely dissolved and pose a threat to marine life due to increased bioavailability. Given the filter-feeding ability of sponges, we investigated the capacity of four ubiquitous Mediterranean species (Agelas oroides, Axinella cannabina, Chondrosia reniformis and Sarcotragus foetidus) in removing aquaculture-related dissolved organic pollutants. These included individual chemicals belonging to antibiotics (i.e., oxytetracycline), antifouling biocides (i.e., diuron and Irgarol 1051) and polycyclic aromatic hydrocarbons (i.e., 2,6-dimethylnapththalene, phenanthrene). The uptake of pollutants was assessed in vitro by exposing small sponge explants to each chemical for a period of 8 h. Additional "cleanup" experiments were performed for complex mixtures mimicking the dissolved organic material encountered in fish farms, such as filtrates of fish feed and excreta. All sponges exhibited a pronounced preference for lipophilic pollutants and a strong positive correlation was revealed between clearance rate and substrate hydrophobicity. Our best filter-feeder (i.e., A. oroides) was able to clear 10.0 ± 1.3 mL of seawater per hour and per gram of sponge, when exposed to 2,6-dimethylnapththalene. Active pumping was found to be the predominant mechanism dictating the assimilation of dissolved pollutants in all sponge species, as it was 3-10 times faster than pollutants' passive adsorption on sponges' pinacoderm. Additionally, the uptaken pollutants were shown to be strongly retained by sponges and they were hardly released back to seawater as a result of desorption or sponge excretory mechanisms. Our study corroborates that sponges are highly efficient in uptaking dissolved organic compounds and it offers new insights into the kinetics and mechanisms ruling this process.


Asunto(s)
Contaminantes Ambientales , Hidrocarburos Policíclicos Aromáticos , Poríferos , Contaminantes Químicos del Agua , Animales , Cinética , Acuicultura , Contaminantes Químicos del Agua/análisis
7.
J Hazard Mater ; 457: 131710, 2023 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-37276696

RESUMEN

The accumulation of plastic waste in the oceans has caused growing concern for its effects on marine life. The interactions of plastics with environmental factors have been linked to fragmentation to micro- and nanoparticles with different properties and consequences, but the mechanism of fragmentation has not been fully understood yet. In this work, we investigate the combined effect of marine communities and ultraviolet (UV) radiation towards the degradation of virgin and artificially weathered polypropylene (PP) pellets after a long-term incubation period in marine mesocosms. The surface chemical alterations and deterioration of the polymer, in conjunction with the attachment and evolution of marine bacterial communities, the development of biofilm and exopolymeric substances (EPS), as well as the colloidal properties (zeta-potential and hydrodynamic diameter) of the mesocosms were studied. The surface area of both types of pellets decreased over time, despite no concrete weight change being observed. Cell growth, EPS production and colloid particle size were correlated to the loss of area. Therefore, we propose that surface area could be effectively monitored, instead of weight loss, as an alternative indicator of polymer degradation in biodegradation experiments. Changes in the chemical structure of the polymer, in addition to the evolution of the biological factors, implied that a complex degradation process alternated between two phases: an abiotic phase, when UV irradiation contributes to the deterioration of the polymer surface layers and a biotic phase, when marine communities degrade the weathered polymer surface to reveal the underlying layer of virgin polymer. Finally, microscopic particles, produced as a result of the decrease in pellet area, promoted the aggregation of colloidal particles. The role and impacts of these colloidal particles in marine ecosystems are yet as unidentified as that of micro- and nano-sized plastic particles and call for further investigation.


Asunto(s)
Polipropilenos , Contaminantes Químicos del Agua , Ecosistema , Contaminantes Químicos del Agua/química , Plásticos/química , Polímeros
8.
Environ Sci Technol ; 57(21): 8130-8138, 2023 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-37194994

RESUMEN

The durability of plastics in the marine environment has emerged as a crucial environmental issue. However, the contribution of several factors and the threshold point after which a plastic product generates secondary micro- and nanoplastics is still unclear. To investigate the interaction of environmental parameters with the physicochemical properties of polyethylene (PE) and polypropylene (PP) films in the marine environment, polyolefin films were subjected to weathering in emulated coastal and marine environments for 12 months, focusing on the relationship between radiation load, alteration on the surface, and subsequent generation of microplastics (MPs). The weight average molecular weight (Mw) was found to be strongly correlated with the generated particles and the Feret diameter, implying the generation of secondary microplastics at decreased Mw. A significant and strong relationship between the carbonyl index (CI) and the Feret diameter for PP films weathered on beach sand was identified. This CI-fragmentation relationship involves three sequential stages and suggests that spontaneous fragmentation occurs at CI values above 0.7.


Asunto(s)
Plásticos , Contaminantes Químicos del Agua , Plásticos/química , Microplásticos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Polipropilenos
9.
Environ Pollut ; 316(Pt 1): 120725, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36427827

RESUMEN

European marine waters are infested with plastic, with an average density of 1 plastic item in every four square-meters. Research relevant to MPs-NPs ingestion by wild decapods in European waters is limited, none of which regards the European spiny lobster. Totally 4102 plastic particles were extracted from the spiny lobster stomach tissues of both sexes. Out of the 63 samples analysed only three (4.8%) of them were found with no plastic particles. The range of number of MPs in stomachs was from 20 to 273 MPs individual-1. The 98.3% were fragments. In total 3833 plastic particles were extracted from the gill tissues of both sexes. MPs were found in all samples (n = 50),99.2% of the detected particles were fragments. The MPs detected in gills ranged from 11 to 339 MPs individual-1. The DLS method was used in order to evaluate the NPs presence. Nanoplastics were detected in 22.6% of stomachs and in the 48.1% of gills. A total of 43 polymer types were identified in both tissues. Also, our study assessed the accumulation of heavy metals at the edible tail muscle. Certain elements were detected above the EU's Maximum Residue Level, including arsenic. The present results are alarming and the potential human health implications could be serious.


Asunto(s)
Metales Pesados , Palinuridae , Contaminantes Químicos del Agua , Animales , Humanos , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Grecia , Metales Pesados/análisis , Plásticos
10.
Microorganisms ; 10(10)2022 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-36296296

RESUMEN

The interactions between marine bacteria and particulate matter play a pivotal role in the biogeochemical cycles of carbon and associated inorganic elements in the oceans. Eutrophic plumes typically form around nutrient-releasing particles and host intense bacterial activities. However, the potential of bacteria to reshape the nutrient plumes remains largely unexplored. We present a high-resolution numerical analysis for the impacts of nutrient uptake by free-living bacteria on the pattern of dissolution around slow-moving particles. At the single-particle level, the nutrient field is parameterized by the Péclet and Damköhler numbers (0 < Pe < 1000, 0 < Da < 10) that quantify the relative contribution of advection, diffusion and uptake to nutrient transport. In spite of reducing the extent of the nutrient plume in the wake of the particle, bacterial uptake enhances the rates of particle dissolution and nutrient depletion. These effects are amplified when the uptake timescale is shorter than the plume lifetime (Pe/Da < 100, Da > 0.0001), while otherwise they are suppressed by advection or diffusion. Our analysis suggests that the quenching of eutrophic plumes is significant for individual phytoplankton cells, as well as marine aggregates with sizes ranging from 0.1 mm to 10 mm and sinking velocities up to 40 m per day. This microscale process has a large potential impact on microbial growth dynamics and nutrient cycling in marine ecosystems.

11.
J Environ Manage ; 302(Pt B): 114076, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34781052

RESUMEN

In this study two plant species, Punica granatum L. and Myrtus communis L., have been tested as candidates for phytoremediation of olive mill wastewater (OMW) through recirculation in soil pilot units, according to the proposed patented technology by Santori and Cicalini [EP1216963 A. 26 Jun 2002]. Wastewater was treated in batches of low to high organics strength (COD: 2 700-45 700 mg/L) during summer months of two consecutive years. Dynamics of the most important wastewater parameters were investigated, and corresponding removal rates were estimated. During treatment of low organic load OMW, average removal rate of organics, phenolics, total nitrogen and total phosphorus were 0.68 g-COD/kg-soil d, 0.073 g-TPh/kg-soil d, 0.033 g-TN/kg-soil d and 0.0074 g-TP/kg-soil d respectively and plants proved to be tolerant to the OMW. During treatment of high organic load OMW removal rates were roughly 10-fold higher although phytotoxic symptoms were observed. Plants were found to contribute greatly to the OMW treatment process since organics removal rates in pilot units were found to be at least 10-fold higher than in wastewater treatment in non-vegetated soil. Plant species with high added value products such as pomegranate and myrtle trees were used in this study, improving the circular economy potential of the aforementioned technology. Moreover, its efficiency has been demonstrated by quantification of the overall removal rates of key constituents as well as the contribution of the plants in the OMW treatment.


Asunto(s)
Olea , Aguas Residuales , Biodegradación Ambiental , Residuos Industriales/análisis , Aceite de Oliva , Eliminación de Residuos Líquidos
12.
Sci Total Environ ; 804: 150141, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34509832

RESUMEN

Microplastics (MPs) have been detected in atmosphere, soil, and water and have been characterized as contaminants of emerging concern. When exposed to these environments, MPs interact with the chemical compounds as well as the (micro)organisms inhabiting these ecosystems. This paper overviews the interactions and significant factors influencing the sorption process of antibiotics on MPs since distinct interactions are developed between MPs and antibiotics. The interplay between the MPs and the antibiotic resistant genes (ARGs) microbial hosts is presented and the important factors that may shape the plastisphere resistome are discussed. The interactions of MPs, antibiotics and antibiotic resistant bacteria (ARB) and ARGs in wastewater treatment plants (WWTPs) were discussed with the aim to provide a perspective for better understanding of the role of WWTPs in bringing together MPs, antibiotics and ARB/ARGs and further as release points of MPs carrying antibiotics, and ARB/ARGs.


Asunto(s)
Microplásticos , Purificación del Agua , Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina , Antibacterianos/farmacología , Farmacorresistencia Microbiana/genética , Ecosistema , Genes Bacterianos , Plásticos , Aguas Residuales
13.
Plants (Basel) ; 12(1)2022 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-36616220

RESUMEN

Antimony (Sb) is considered to be a toxic metalloid of increasing prevalence in the environment. Although several phytoremediation studies have been conducted, research regarding the mechanisms of Sb accumulation and translocation within plants remains limited. In this study, soil from a shooting range was collected and spiked with an initial Sb(III) concentration of 50 mg/kg. A pot experiment was conducted to investigate whether Nerium oleander could accumulate Sb in the root and further translocate it to the aboveground tissue. Biostimulation of the soil was performed by the addition of organic acids (OAs), consisting of citric, ascorbic, and oxalic acid at low (7 mmol/kg) or high (70 mmol/kg) concentrations. The impact of irrigation with water supplemented with oxygen nanobubbles (O2NBs) was also investigated. The results demonstrate that there was a loss in plant growth in all treatments and the presence of OAs and O2NBs assisted the plant to maintain the water content at the level close to the control. The plant was not affected with regards to chlorophyll content in all treatments, while the antioxidant enzyme activity of guaiacol peroxidase (GPOD) in the roots was found to be significantly higher in the presence of Sb. Results revealed that Sb accumulation was greater in the treatment with the highest OAs concentration, with a bioconcentration factor greater than 1.0. The translocation of Sb for every treatment was very low, confirming that N. oleander plant cannot transfer Sb from the root to the shoots. A higher amount of Sb was accumulated in the plants that were irrigated with the O2NBs, although the translocation of Sb was not increased. The present study provides evidence for the phytoremediation capacity of N. oleander to bioaccumulate Sb when assisted by biostimulation with OAs.

14.
Wound Repair Regen ; 29(6): 1062-1079, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34655455

RESUMEN

Non-healing wounds are steadily becoming a global-health issue. Prolonged hypoxia propagates wound chronicity; yet, oxygenating treatments are considered inadequate to date. Dissolved oxygen (DO) in aqueous solutions introduces a novel approach to enhanced wound oxygenation, and is robustly evaluated for clinical applications. A systematic literature search was conducted, whereby experimental and clinical studies of DO technologies were categorized per engineering approach. Technical principles, methodology, endpoints and outcomes were analysed for both oxygenating and healing effects. Forty articles meeting our inclusion criteria were grouped as follows: DO solutions (17), oxygen (O2 ) dressings (9), O2 hydrogels (11) and O2 emulsions (3). All technologies improved wound oxygenation, each to a variable degree. They also achieved at least one statistically significant outcome related to wound healing, mainly in epithelialization, angiogenesis and collagen synthesis. Scarcity in clinical data and methodological variability precluded quantitative comparisons among the biotechnologies studied. DO technologies warrantee further evaluation for wound oxygenation in the clinical setting. Standardised methodologies and targeted research questions are pivotal to facilitate global integration in healthcare.


Asunto(s)
Oxígeno , Cicatrización de Heridas , Vendajes , Hidrogeles
15.
Sci Total Environ ; 793: 148526, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34175606

RESUMEN

Plastic pollution is presently one of the most widespread and minimally understood problems. Vast quantities of plastics that have entered the marine environment should be detected floating on the sea surface are seemingly missing from the global budget. A vertical transfer process should be able to explain the imbalance in mass, as well as the findings of buoyant plastics at the bottom of the sea. These processes are of paramount importance to modelling efforts on the fate of plastics and microplastics in the marine environment. In order to fill this gap and develop correlations that could be used in modelling activities, we have designed and performed a 300-day long field experiment to monitor the interactions between microplastics (pellets and films) and the marine environment for five types of plastic polymers. Fouling, changes in diameter, gravimetric weight and sinking velocity were monitored and the correlations between them were studied using principal component analysis (PCA). Density, fouling and sample form (strip or pellet) were found to greatly affect the sinking characteristics of the polymers, leading to an increase or decrease in the sinking velocity. Finally, mathematical expressions for the estimation of fouling attachment and the sinking velocity with respect to time for each type of plastic were determined from the experimental data.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Contaminación Ambiental , Plásticos , Contaminantes Químicos del Agua/análisis
16.
Mar Drugs ; 20(1)2021 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-35049879

RESUMEN

Chronic discharge of surplus organic matter is a typical side effect of fish aquaculture, occasionally leading to coastal eutrophication and excessive phytoplankton growth. Owing to their innate filter-feeding capacity, marine sponges could mitigate environmental impact under integrated multitrophic aquaculture (IMTA) scenarios. Herein, we investigated the clearance capacity of four ubiquitous Mediterranean sponges (Agelas oroides, Axinella cannabina, Chondrosia reniformis and Sarcotragus foetidus) against three microalgal substrates with different size/motility characteristics: the nanophytoplankton Nannochloropsis sp. (~3.2 µm, nonmotile) and Isochrysis sp. (~3.8 µm, motile), as well as the diatom Phaeodactylum tricornutum (~21.7 µm, nonmotile). In vitro cleaning experiments were conducted using sponge explants in 1 L of natural seawater and applying different microalgal cell concentrations under light/dark conditions. The investigated sponges exhibited a wide range of retention efficiencies for the different phytoplankton cells, with the lowest average values found for A. cannabina (37%) and the highest for A. oroides (70%). The latter could filter up to 14.1 mL seawater per hour and gram of sponge wet weight, by retaining 100% of Isochrysis at a density of 105 cells mL-1, under darkness. Our results highlight differences in filtering capacity among sponge species and preferences for microalgal substrates with distinct size and motility traits.


Asunto(s)
Microalgas , Poríferos , Animales , Acuicultura , Organismos Acuáticos , Mar Mediterráneo , Agua de Mar
17.
Sci Total Environ ; 748: 142427, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-33113705

RESUMEN

Microplastics (MPs), defined as particles with diameters <5 mm and including nanoplastics (NPs), with diameters <1 µm, are characterized by large specific surface areas and hydrophobicity. In aquatic and terrestrial environments, MPs interact with co-occurring organic pollutants through sorption and desorption, which alters the environmental behavior of the pollutants, such as their toxicity, bioaccumulation, degradation, and transport. In this review, we summarize the results of current studies of the interactions between MPs and organic contaminants, and focus on the different mechanisms and subsequent ecological risks of contaminant transfer among environmental media, MPs and organisms. The sorption/desorption of organic pollutants on/from MPs is discussed with respect to solution conditions and the properties of both the MPs and the pollutants. More importantly, the ability of MPs to alter the toxicity, bioaccumulation, degradation, and transport of organic pollutants through these interactions is considered as well. We then examine the interrelationships of the different environmental behaviors of MPs and organic pollutants and the roles played by environmental processes. Finally, we identify the remaining knowledge gaps that must be filled in further studies in order to accurately evaluate the environmental risks of MPs and their associated organic pollutants.

18.
Microorganisms ; 7(10)2019 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-31554215

RESUMEN

The microbiome associated with plants used in phytodepuration systems can boost plant growth and services, especially in ecosystems dealing with recalcitrant compounds, hardly removed via traditional wastewater (WW) treatments, such as azo-dyes used in textile industry. In this context, we aimed to study the cultivable microbiome selected by Phragmites australis plants in a Constructed Wetland (CW) in Morocco, in order to obtain candidate inoculants for the phytodepuration of azo-dye contaminated WW. A collection of 152 rhizospheric and endophytic bacteria was established. The strains were phylogenetically identified and characterized for traits of interest in the phytodepuration context. All strains showed Plant Growth Promotion potential in vitro and 67% of them significantly improved the growth of a model plant in vivo compared to the non bacterized control plants. Moreover, most of the isolates were able to grow in presence of several model micropollutants typically found in WW, indicating their potential use in phytodepuration of a wide spectrum of effluents. The six most promising strains of the collection were tested in CW microcosms alone or as consortium: the consortium and two single inocula demonstrated to significantly increase the removal of the model azo-dye Reactive Black 5 compared to the non bacterized controls.

19.
J Hazard Mater ; 375: 33-42, 2019 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-31039462

RESUMEN

This work sheds light on the physicochemical changes of naturally weathered polymer surfaces along with changes of polymer buoyancy due to biofilm formation and degradation processes. To support the degradation hypothesis, a microcosm experiment was conducted where a mixture of naturally weathered plastic pieces was incubated with an indigenous pelagic community. A series of analyses were employed in order to describe the alteration of the physicochemical characteristics of the polymer (FTIR, SEC and GPC, sinking velocity) as well as the biofilm community (NGS). At the end of phase II, the fraction of double bonds in the surface of microbially treated PE films increased while changes were also observed in the profile of the PS films. The molecular weight of PE pieces increased with incubation time reaching the molecular weight of the virgin pieces (230,000 g mol-1) at month 5 but the buoyancy displayed no difference throughout the experimental period. The number-average molecular weight of PS pieces decreased (33% and 27% in INDG and BIOG treatment respectively), implying chain scission; accelerated (by more than 30%) sinking velocities compared to the initial weathered pieces were also measured for PS films with biofilm on their surface. The orders Rhodobacterales, Oceanospirillales and Burkholderiales dominated the distinct platisphere communities and the genera Bacillus and Pseudonocardia discriminate these assemblages from the planktonic counterpart. The functional analysis predicts overrepresentation of adhesive cells carrying xenobiotic and hydrocarbon degradation genes. Taking these into account, we can suggest that tailored marine consortia have the ability to thrive in the presence of mixtures of plastics and participate in their degradation.


Asunto(s)
Consorcios Microbianos/fisiología , Polietileno/metabolismo , Poliestirenos/metabolismo , Agua de Mar/microbiología , Bacterias/genética , Bacterias/metabolismo , Fenómenos Fisiológicos Bacterianos , Biodegradación Ambiental , Biopelículas , Plancton/fisiología , Polietileno/química , Poliestirenos/química , ARN Ribosómico 16S , Microbiología del Agua
20.
N Biotechnol ; 52: 94-103, 2019 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-31146037

RESUMEN

The occurrence of emerging organic contaminants (EOCs) in wastewaters and the inability of the conventional wastewater treatments plants to deal with them have been pointed out several times over the last few years. As a result, remnants of those compounds released into the aquatic environment present a potential risk for public health. Constructed wetlands (CWs) have been proposed as environmentally friendly, low-cost alternative systems with satisfactory results for different types of contaminants. This study aimed to evaluate the efficiency of a CW system, planted with the halophyte Juncus acutus, to eliminate bisphenol A (BPA) and two antibiotics, namely ciprofloxacin (CIP) and sulfamethoxazole (SMX) under different operating conditions. The behavior of Escherichia coli and enterococcal populations in terms of changes in their resistance profile for the selected antibiotics and the abundance of two resistance genes (qnrA and sul1) were also examined. BPA and CIP were significantly removed by the CW, with an overall removal of 76.2% and 93.9% respectively and with the plants playing a vital role. In contrast, SMX was not significantly eliminated. Moreover, fluctuations in the antibiotic resistance profile of bacteria were observed. Treatment processes affected the response of the two selected bacterial indicators, depending on the conditions employed in each case. Furthermore, increased levels of resistance genes were monitored in the system effluent. This study indicates that CWs, as tertiary wastewater treatment systems, may demonstrate high removal rates for some but not all EOCs. This implies that each EOC identified in the feed stream should be tested assiduously by analyzing the final effluents before their reuse or discharge into water bodies.


Asunto(s)
Bacterias/metabolismo , Farmacorresistencia Microbiana , Compuestos Orgánicos/aislamiento & purificación , Aguas Residuales/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Humedales , Antibacterianos/aislamiento & purificación , Compuestos de Bencidrilo/aislamiento & purificación , Fenoles/aislamiento & purificación , Reología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...