Cultivable microalgae diversity from a freshwater aquaculture filtering system and its potential for polishing aquaculture-derived water streams.

AIMS: Microalgae are ubiquitous in aquatic environments, including aquaculture farms, but few studies have delved into their phytoplankton diversity and bioremediation potential. In this study, the cultivable phytoplankton of a rainbow trout freshwater aquaculture farm was isolated, phylogenetically analysed and used to assemble a consortium to polish an aquaculture-derived effluent, with low concentrations of ammonium, nitrite and nitrate. METHODS AND RESULTS: Through standard plating in different selective media, a total of 15 microalgae strains were isolated from sludge from a rotary drum filtering system which removes suspended solids from the water exiting the facility. Based on 18S rRNA gene sequences, isolates were assigned to nine different genera of the Chlorophyta phylum: Asterarcys, Chlorella, Chloroccocum, Chlorosarcinopsis, Coelastrella, Desmodesmus, Micractinium, Parachlorella and Scenedesmus. Species from most of these genera are known to inhabit freshwater systems in Galicia and continental Spain, but the Coelastrella, Asterarcys or Parachlorella genera are not usually present in freshwater streams. In an onsite integrative approach, the capacity of a consortium of native microalgae isolates to grow on aquaculture-derived effluents and its nutrient removal capacity were assessed using a raceway pond. After 7 days, removal efficiencies of approximately 99%, 92% and 49% for ammonium, nitrite and nitrate, respectively, were achieved concomitantly with a microalgae biomass increase of ca. 17%. CONCLUSIONS: Sludge from the aquaculture filtering system presents a high diversity of microalgae species from the Chlorophyta phylum, whose application in a consortial approach revealed to be efficient to polish aquaculture-derived effluents with low nutrient content. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of native microalgae consortia from aquaculture systems can contribute to the development of efficient treatment systems for low-nutrient wastewater, avoiding nutrients release to the environment and promoting water recirculation. This may further strengthen the use of phycoremediation at the industrial scale, as an environment-friendly strategy.

Biodegradation and Metabolic Pathway of 17ß-Estradiol by Rhodococcus sp. ED55.

Endocrine disrupting compounds (EDCs) in the environment are considered a motif of concern, due to the widespread occurrence and potential adverse ecological and human health effects. The natural estrogen, 17ß-estradiol (E2), is frequently detected in receiving water bodies after not being efficiently removed in conventional wastewater treatment plants (WWTPs), promoting a negative impact for both the aquatic ecosystem and human health. In this study, the biodegradation of E2 by Rhodococcus sp. ED55, a bacterial strain isolated from sediments of a discharge point of WWTP in Coloane, Macau, was investigated. Rhodococcus sp. ED55 was able to completely degrade 5 mg/L of E2 in 4 h in a synthetic medium. A similar degradation pattern was observed when the bacterial strain was used in wastewater collected from a WWTP, where a significant improvement in the degradation of the compound occurred. The detection and identification of 17 metabolites was achieved by means of UPLC/ESI/HRMS, which proposed a degradation pathway of E2. The acute test with luminescent marine bacterium Aliivibrio fischeri revealed the elimination of the toxicity of the treated effluent and the standardized yeast estrogenic (S-YES) assay with the recombinant strain of Saccharomyces cerevisiae revealed a decrease in the estrogenic activity of wastewater samples after biodegradation.

Biodegradation and Metabolic Pathway of the Neonicotinoid Insecticide Thiamethoxam by Labrys portucalensis F11.

Thiamethoxam (TMX) is an effective neonicotinoid insecticide. However, its widespread use is detrimental to non-targeted organisms and water systems. This study investigates the biodegradation of this insecticide by Labrys portucalensis F11. After 30 days of incubation in mineral salt medium, L. portucalensis F11 was able to remove 41%, 35% and 100% of a supplied amount of TMX (10.8 mg L-1) provided as the sole carbon and nitrogen source, the sole carbon and sulfur source and as the sole carbon source, respectively. Periodic feeding with sodium acetate as the supplementary carbon source resulted in faster degradation of TMX (10.8 mg L-1); more than 90% was removed in 3 days. The detection and identification of biodegradation intermediates was performed by UPLC-QTOF/MS/MS. The chemical structure of 12 metabolites is proposed. Nitro reduction, oxadiazine ring cleavage and dechlorination are the main degradation pathways proposed. After biodegradation, toxicity was removed as indicated using Aliivibrio fischeri and by assessing the synthesis of an inducible ß-galactosidase by an E. coli mutant (Toxi-Chromo test). L. portucalensis F11 was able to degrade TMX under different conditions and could be effective in bioremediation strategies.

Actinobacteria isolated from wastewater treatment plants located in the east-north of Algeria able to degrade pesticides.

The pollution of water resources by pesticides poses serious problems for public health and the environment. In this study, Actinobacteria strains were isolated from three wastewater treatment plants (WWTPs) and were screened for their ability to degrade 17 pesticide compounds. Preliminary screening of 13 of the isolates of Actinobacteria allowed the selection of 12 strains with potential for the degradation of nine different pesticides as sole carbon source, including aliette, for which there are no previous reports of biodegradation. Evaluation of the bacterial growth and degradation kinetics of the pesticides 2,4-dichlorophenol (2,4-DCP) and thiamethoxam (tiam) by selected Actinobacteria strains was performed in liquid media. Strains Streptomyces sp. ML and Streptomyces sp. OV were able to degrade 45% of 2,4-DCP (50 mg/l) as the sole carbon source in 30 days and 84% of thiamethoxam (35 mg/l) in the presence of 10 mM of glucose in 18 days. The biodegradation of thiamethoxam by Actinobacteria strains was reported for the first time in this study. These strains are promising for use in bioremediation of ecosystems polluted by this type of pesticides.

Sediments in the mangrove areas contribute to the removal of endocrine disrupting chemicals in coastal sediments of Macau SAR, China, and harbour microbial communities capable of degrading E2, EE2, BPA and BPS.

The occurrence of endocrine disrupting chemicals (EDCs) is a major issue for marine and coastal environments in the proximity of urban areas. The occurrence of EDCs in the Pearl River Delta region is well documented but specific data related to Macao is unavailable. The levels of bisphenol-A (BPA), estrone (E1), 17α-estradiol (αE2), 17ß-estradiol (E2), estriol (E3), and 17α-ethynylestradiol (EE2) were measured in sediment samples collected along the coastline of Macao. BPA was found in all 45 collected samples with lower BPA concentrations associated to the presence of mangrove trees. Biodegradation assays were performed to evaluate the capacity of the microbial communities of the surveyed ecosystems to degrade BPA and its analogue BPS. Using sediments collected at a WWTP discharge point as inoculum, at a concentration of 2 mg l-1 complete removal of BPA was observed within 6 days, whereas for the same concentration BPS removal was of 95% after 10 days, which is particularly interesting since this compound is considered recalcitrant to biodegradation and likely to accumulate in the environment. Supplementation with BPA improved the degradation of bisphenol-S (BPS). Aiming at the isolation of EDCs-degrading bacteria, enrichments were established with sediments supplied with BPA, BPS, E2 and EE2, which led to the isolation of a bacterial strain, identified as Rhodoccoccus sp. ED55, able to degrade the four compounds at different extents. The isolated strain represents a valuable candidate for bioremediation of contaminated soils and waters.

Proposals and Comparisons from One-Sensor EEG and EOG Human-Machine Interfaces.

Human-Machine Interfaces (HMI) allow users to interact with different devices such as computers or home elements. A key part in HMI is the design of simple non-invasive interfaces to capture the signals associated with the user's intentions. In this work, we have designed two different approaches based on Electroencephalography (EEG) and Electrooculography (EOG). For both cases, signal acquisition is performed using only one electrode, which makes placement more comfortable compared to multi-channel systems. We have also developed a Graphical User Interface (GUI) that presents objects to the user using two paradigms-one-by-one objects or rows-columns of objects. Both interfaces and paradigms have been compared for several users considering interactions with home elements.

Assessment of an aerobic granular sludge system in the presence of pharmaceutically active compounds by quantitative image analysis and chemometric techniques.

In this study, a sequencing batch reactor (SBR) with aerobic granular sludge (AGS) was operated with synthetic wastewater containing environmental relevant concentrations of 17ß-estradiol (E2), 17α-ethinylestradiol (EE2) and sulfamethoxazole (SMX). Despite the presence of the studied PhAC, the granular fraction clearly predominated (TSSgran/TSS ranging from 0.82 to 0.98) throughout the monitoring period, presenting aggregates with high organic fraction (VSS/TSS above 0.83) and good settling characteristics (SVI5 ranging from 15 to 39 mL/gTSS). A principal component analysis (PCA) with quantitative image analysis (QIA) based data allowed to distinguish the different operational periods, namely with mature granules (CONT), and the E2, EE2, and SMX feeding periods. It further revealed a positive relationship between the biomass density, sludge settling ability, overall and granular biomass contents, granulation properties, granular biomass fraction and large granules fraction and size. Moreover, a discriminant analysis (DA) allowed to successfully discriminate not only the different operational periods, mainly by using the floccular apparent density, granular stratification and contents data, but also the PhAC presence in samples. The filamentous bacteria contents, sludge settling properties, settling properties stability and granular stratification, structure and contents parameters were found to be crucial for that purpose.

Simultaneous nitrification and phosphate removal by bioaugmented aerobic granules treating a fluoroorganic compound.

The presence of toxic compounds in wastewater can cause problems for organic matter and nutrient removal. In this study, the long-term effect of a model xenobiotic, 2-fluorophenol (2-FP), on ammonia-oxidizing bacteria (AOB), nitrite oxidizing bacteria (NOB) and phosphate accumulating organisms (PAO) in aerobic granular sludge was investigated. Phosphate (P) and ammonium (N) removal efficiencies were high (>93%) and, after bioaugmentation with 2-FP degrading strain FP1, 2-FP was completely degraded. Neither N nor P removal were affected by 50 mg L-1 of 2-FP in the feed stream. Changes in the aerobic granule bacterial communities were followed. Numerical analysis of the denaturing gradient gel electrophoresis (DGGE) profiles showed low diversity for the ammonia monooxygenase (amoA) gene with an even distribution of species. PAOs, including denitrifying PAO (dPAO), and AOB were present in the 2-FP degrading granules, although dPAO population decreased throughout the 444 days reactor operation. The results demonstrated that the aerobic granules bioaugmented with FP1 strain successfully removed N, P and 2-FP simultaneously.

FDD Channel Estimation via Covariance Estimation in Wideband Massive MIMO Systems.

A method for channel estimation in wideband massive MIMO systems using hybrid digital analog architectures is developed. The proposed method is useful for FDD at either sub-6 GHz or mmWave frequency bands and takes into account the beam squint effect caused by the large bandwidth of the signals. To circumvent the estimation of large channel vectors, the posed algorithm relies on the slow time variation of the channel spatial covariance matrix, thus allowing for the utilization of very short training sequences. This is possibledue to the exploitation of the channel structure. After identifying the channel covariance matrix, the channel is estimated on the basis of the recovered information. To that end, we propose a novel method that relies on estimating the tap delays and the gains as sociated with each path. As a consequence, the proposed channel estimator achieves low computational complexity and significantly reduces the training overhead. Moreover, our numerical simulations show better performance results compared to the minimum mean-squared error solution.

Synergistic effects of arbuscular mycorrhizal fungi and plant growth-promoting bacteria benefit maize growth under increasing soil salinity.

Salt-affected soils are a major problem worldwide for crop production. Bioinocula such as plant growth-promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF) can help plants to thrive in these areas but interactions between them and with soil conditions can modulate the effects on their host. To test potential synergistic effects of bioinoculants with intrinsically different functional relationships with their host in buffering the effect of saline stress, maize plants were grown under increasing soil salinity (0-5 g NaCl kg--1 soil) and inoculated with two PGPB strains (Pseudomonas reactans EDP28, and Pantoea alli ZS 3-6), one AMF (Rhizoglomus irregulare), and with the combination of both. We then modelled biomass, ion and nutrient content in maize plants in response to increasing salt concentration and microbial inoculant treatments using generalized linear models. The impacts of the different treatments on the rhizosphere bacterial communities were also analyzed. Microbial inoculants tended to mitigate ion imbalances in plants across the gradient of NaCl, promoting maize growth and nutritional status. These effects were mostly prominent in the treatments comprising the dual inoculation (AMF and PGPB), occurring throughout the gradient of salinity in the soil. The composition of bacterial communities of the soil was not affected by microbial treatments and were mainly driven by salt exposure. The tested bioinocula are most efficient for maize growth and health when co-inoculated, increasing the content of K+ accompanied by an effective decrease of Na+ in plant tissues. Moreover, synergistic effects potentially contribute to expanding crop production to otherwise unproductive soils. Results suggest that the combination of AMF and PGPB leads to interactions that may have a potential role in alleviating the stress and improve crop productivity in salt-affected soils.

Enantioselective degradation of ofloxacin and levofloxacin by the bacterial strains Labrys portucalensis F11 and Rhodococcus sp. FP1.

Fluoroquinolones are a class of antibiotics widely prescribed in both human and veterinary medicine of high environmental concern and characterized as environmental micropollutants due to their ecotoxicity and persistence and antibacterial resistance potential. Ofloxacin and levofloxacin are chiral fluoroquinolones commercialized as racemate and in enantiomerically pure form, respectively. Since the pharmacological properties and toxicity of the enantiomers may be very different, understanding the stereochemistry of these compounds should be a priority in environmental monitoring. This work presents the biodegradation of racemic ofloxacin and its (S)-enantiomer levofloxacin by the bacterial strains Labrys portucalensis F11 and Rhodococcus sp. FP1 at a laboratory-scale microcosm following the removal and the behavior of the enantiomers. Strain F11 could degrade both antibiotics almost completely when acetate was supplied regularly to the cultures. Enrichment of the (R)-enantiomer was observed in FP1 and F11 cultures supplied with ofloxacin. Racemization was observed in the biodegradation of the pure (S)-ofloxacin (levofloxacin) by strain F11, which was confirmed by liquid chromatography - exact mass spectrometry. Biodegradation of ofloxacin at 450 µg L-1 by both bacterial strains expressed good linear fits (R2 > 0.98) according to the Rayleigh equation. The enantiomeric enrichment factors were comprised between - 22.5% to - 9.1%, and - 18.7% to - 9.0% in the biodegradation of ofloxacin by strains F11 and FP1, respectively, with no significant differences for the two bacteria under the same conditions. This is the first time that enantioselective biodegradation of ofloxacin and levofloxacin by single bacteria is reported.

Bacterial community dynamics within an aerobic granular sludge reactor treating wastewater loaded with pharmaceuticals.

Pharmaceuticals are micropollutants often present in wastewater treatment systems. In this study, the potential impact of such micropollutants on the bacterial population within aerobic granular sludge (AGS) bioreactor was investigated. The AGS bacterial community structure and composition were accessed combining DGGE fingerprinting and barcoded pyrosequencing analysis. Both revealed the existence of a dynamic bacterial community, independently of the pharmaceuticals presence. The AGS microbiome at both phylum and class levels varied over time and, after stopping pharmaceuticals feeding, the bacterial community did not return to its initial composition. Nevertheless, most of the assigned OTUs were present throughout the different operational phases. This core microbiome, represented by over 72% of the total sequences in each phase, probably played an important role in biological removal processes, avoiding their failure during the disturbance period. Quantitative-PCR revealed that pharmaceuticals load led to gradual changes on the abundance of ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB) and polyphosphate-accumulating organisms (PAO) but their persistence during that phase demonstrated the resilience of such bacterial groups. AGS microbiome changed over time but a core community was maintained, probably ensuring the accomplishment of the main biological removal processes.

Biodegradation of Diclofenac by the bacterial strain Labrys portucalensis F11.

Diclofenac (DCF) is a widely used non-steroidal anti-inflammatory pharmaceutical which is detected in the environment at concentrations which can pose a threat to living organisms. In this study, biodegradation of DCF was assessed using the bacterial strain Labrys portucalensis F11. Biotransformation of 70% of DCF (1.7-34 µM), supplied as the sole carbon source, was achieved in 30 days. Complete degradation was reached via co-metabolism with acetate, over a period of 6 days for 1.7 µM and 25 days for 34 µM of DCF. The detection and identification of biodegradation intermediates was performed by UPLC-QTOF/MS/MS. The chemical structure of 12 metabolites is proposed. DCF degradation by strain F11 proceeds mainly by hydroxylation reactions; the formation of benzoquinone imine species seems to be a central step in the degradation pathway. Moreover, this is the first report that identified conjugated metabolites, resulting from sulfation reactions of DCF by bacteria. Stoichiometric liberation of chlorine and no detection of metabolites at the end of the experiments are strong indications of complete degradation of DCF by strain F11. To the best of our knowledge this is the first report that points to complete degradation of DCF by a single bacterial strain isolated from the environment.

Calculation of the Connected Dominating Set Considering Vertex Importance Metrics.

The computation of a set constituted by few vertices to define a virtual backbone supporting information interchange is a problem that arises in many areas when analysing networks of different natures, like wireless, brain, or social networks. Recent papers propose obtaining such a set of vertices by computing the connected dominating set (CDS) of a graph. In recent works, the CDS has been obtained by considering that all vertices exhibit similar characteristics. However, that assumption is not valid for complex networks in which their vertices can play different roles. Therefore, we propose finding the CDS by taking into account several metrics which measure the importance of each network vertex e.g., error probability, entropy, or entropy variation (EV).

Growing substrates for aromatic plant species in green roofs and water runoff quality: pilot experiments in a Mediterranean climate.

Green roof technology has evolved in recent years as a potential solution to promote vegetation in urban areas. Green roof studies for Mediterranean climates, where extended drought periods in summer contrast with cold and rainy periods in winter, are still scarce. The present research study assesses the use of substrates with different compositions for the growth of six aromatic plant species - Lavandula dentata, Pelargonium odoratissimum, Helichrysum italicum, Satureja montana, Thymus caespititius and T. pseudolanuginosus, during a 2-year period, and the monitoring of water runoff quality. Growing substrates encompassed expanded clay and granulated cork, in combination with organic matter and crushed eggshell. These combinations were adequate for the establishment of all aromatic plants, allowing their propagation in the extensive system located on the 5th storey. The substrate composed of 70% expanded clay and 30% organic matter was the most suitable, and crushed eggshell incorporation improved the initial plant establishment. Water runoff quality parameters - turbidity, pH, conductivity, NH4+, NO3-, PO43- and chemical oxygen demand - showed that it could be reused for non-potable uses in buildings. The present study shows that selected aromatic plant species could be successfully used in green roofs in a Mediterranean climate.

Water masses surface temperatures assessment and their effect on surrounding environment.

The aim of this study was to evaluate the effect of water masses on the surface temperature with direct impact on the surrounding area. Three systems were used for the study: a fully vegetated system (subsurface flow constructed wetland (CW)), a lake with no vegetation and a lake partially vegetated with Lemna minor. Infrared thermography was applied for the different systems analysis, allowing the determination of the surface temperature spatial distribution. In general, the presence of plants and water in the analyzed systems contributed to lowering the surface temperatures when comparing to its surroundings. Differences up to about 22 °C were observed in the temperature between the CW canopy and the surrounding soil, and up to about 19 °C between the lake and the surrounding border. Different plant species (Canna flaccida, Canna indica and Zantedeschia aethiopica) inhabiting the CW were also compared and slightly higher average surface temperatures were observed for C. indica. The above mentioned results are relevant in terms of supporting a strategy for water systems inclusion, for example a lake or a CW, in a site as means of having influence in the surface temperature and to some extent in the heat island effect supporting a sustainable environmental management.

SiDIVS: Simple Detection of Inductive Vehicle Signatures with a Multiplex Resonant Sensor.

This work provides a system capable of obtaining simultaneous inductive signatures of vehicles traveling on a roadway with minimal cost. Based on Time-Division Multiplexing (TDM) with multiple oscillators, one for each inductive loop, the proposed system detects the presence of vehicles by means of a shift in the oscillation period of the selected loop and registers the signature of the detected vehicles by measuring the duration of a fixed number of oscillator pulses. In order to test the system in an actual environment, we implement a prototype that we denote as SiDIVS (Simple Detection of Inductive Vehicle Signatures) and acquire different vehicle inductive signatures under real scenarios. We also test the robustness of the detector by simulating the effect of noise on the signature acquisition.

Contributions to the design of rainwater harvesting systems in buildings with green roofs in a Mediterranean climate.

Green roofs (GRs) are becoming a trend in urban areas, favouring thermal performance of buildings, promoting removal of atmospheric pollutants, and acting as possible water collection spots. Rainwater harvesting systems in buildings can also contribute to the management of stormwater runoff reducing flood peaks. These technologies should be enhanced in Mediterranean countries where water scarcity is increasing and the occurrence of extreme events is becoming very significant, as a result of climate change. An extensive pilot GR with three aromatic plant species, Satureja montana, Thymus caespititius and Thymus pseudolanuginosus, designed to study several parameters affecting rainwater runoff, has been in operation for 12 months. Physico-chemical analyses of roof water runoff (turbidity, pH, conductivity, NH4(+), NO3(-), PO4(3-), chemical oxygen demand) have shown that water was of sufficient quality for non-potable uses in buildings, such as toilet flushing. An innovative approach allowed for the development of an expression to predict a 'monthly runoff coefficient' of the GR system. This parameter is essential when planning and designing GRs combined with rainwater harvesting systems in a Mediterranean climate. This study is a contribution to improving the basis for the design of rainwater harvesting systems in buildings with extensive GRs under a Mediterranean climate.

Vehicle Classification Using the Discrete Fourier Transform with Traffic Inductive Sensors.

Inductive Loop Detectors (ILDs) are the most commonly used sensors in traffic management systems. This paper shows that some spectral features extracted from the Fourier Transform (FT) of inductive signatures do not depend on the vehicle speed. Such a property is used to propose a novel method for vehicle classification based on only one signature acquired from a sensor single-loop, in contrast to standard methods using two sensor loops. Our proposal will be evaluated by means of real inductive signatures captured with our hardware prototype.

Assessment of rhizospheric culturable bacteria of Phragmites australis and Juncus effusus from polluted sites.

This study aimed at the isolation and characterization of metal(loid)-tolerant bacteria from the rhizosphere of Phragmites australis and Juncus effusus plants growing in two long-term contaminated sites in Northern Portugal. Site 1 had higher contamination than Site 3. Bacteria were isolated using metal(loid)-supplemented (Cd, Zn, and As) media. Isolates were grouped by random amplified polymorphic DNA and identified by 16S rRNA gene sequencing. Strains were also examined for their metal(loid) tolerance. The counts of metal(loid)-tolerant bacteria were higher in Site 1 and ranged between log 7.17 CFU g(-1) soil in As-containing medium and log 7.57 CFU g(-1) soil in Zn-containing medium, while counts at Site 3 varied between log 5.33 CFU g(-1) soil in Cd-containing medium and log 6.97 CFU g(-1) soil in As-containing medium. The composition of bacterial populations varied between locations. In Site 1, the classes Actinobacteria (36%) and Bacilli (24%) were well represented, while in Site 3 strains were mainly affiliated to classes Actinobacteria (35%), γ-Proteobacteria (35%), and ß-Proteobacteria (12%). The order of metal(loid) toxicity for the isolated strains was Cd > As > Zn. Overall, 10 strains grew at 500 mg Cd L(-1) , 1000 mg Zn L(-1) , and 500 mg As L(-1) , being considered the most metal(loid)-tolerant bacteria. These strains belonged to genera Cupriavidus, Burkholderia, Novosphingobium, Sphingobacterium, Castellaniella, Mesorhizobium, Chryseobacterium, and Rhodococcus and were mainly retrieved from Site 1. The multiple metal(loid)-tolerant strains isolated in this study have potential to be used in bioremediation/phytoremediation.