Cátia Santos

Winery wastewater treatment by combination of Cryptococcus laurentii and Fenton's reagent.

Winery wastewaters (WW) have high levels of organic matter, resulting in high COD and BOD and suspended solids. This paper studies the combination of biological and chemical processes in WW treatment. Among 10 yeast isolates, Filobasidium sp. (AGG 577) and Cryptococcus laurentii (AGG 726) were selected due to their superior performance in COD removal. During WW degradation, COD and total polyphenols (TPP) content removal of 89-90% for Filobasidium sp. and 90-93% for C. laurentii were obtained. However, despite similar degradation efficiency for both yeasts, COD kinetics and pH evolution during treatment reveals that C. laurentii presents a faster response than Filobasidium sp. The toxicity (inhibition of Vibrio fischeri luminescence) of C. laurentii treated WW decreases to an inhibition value below 2.5%. However, treated WW exceeds the legal limits, making necessary an additional treatment. In this case, the selection of Fentons reagent as a chemical final polish step process is a good compromise between efficiency and lower practical complexity. The best results for both COD and TPP removal were obtained with H2O2 initial concentration of 39.2mM and a H2O2:Fe(2+) molar ratio of 15:1. The combined C. laurentii - Fentons reagent treatment of WW achieved a total reduction of 98% and 96%, for COD and TPP, respectively.

Characterization of Cholinesterases in Plasma of Three Portuguese Native Bird Species: Application to Biomonitoring

Over the last decades the inhibition of plasma cholinesterase (ChE) activity has been widely used as a biomarker to diagnose organophosphate and carbamate exposure. Plasma ChE activity is a useful and non-invasive method to monitor bird exposure to anticholinesterase compounds; nonetheless several studies had shown that the ChE form(s) present in avian plasma may vary greatly among species. In order to support further biomonitoring studies and provide reference data for wildlife risk-assessment, plasma cholinesterase of the northern gannet (Morus bassanus), the white stork (Ciconia ciconia) and the grey heron (Ardea cinerea) were characterized using three substrates (acetylthiocholine iodide, propionylthiocholine iodide, and S-butyrylthiocholine iodide) and three ChE inhibitors (eserine sulphate, BW284C51, and iso-OMPA). Additionally, the range of ChE activity that may be considered as basal levels for non-exposed individuals was determined. The results suggest that in the plasma of the three species studied the main cholinesterase form present is butyrylcholinesterase (BChE). Plasma BChE activity in non-exposed individuals was 0.48±0.11 SD U/ml, 0.39±0.12 SD U/ml, 0.15±0.04 SD U/ml in the northern gannet, white stork and grey heron, respectively. These results are crucial for the further use of plasma BChE activity in these bird species as a contamination bioindicator of anti-cholinesterase agents in both wetland and marine environments. Our findings also underscore the importance of plasma ChE characterization before its use as a biomarker in biomonitoring studies with birds.

A multiple index integrating different levels of organization

Many methods in freshwater biomonitoring tend to be restricted to a few levels of biological organization, limiting the potential spectrum of measurable of cause-effect responses to different anthropogenic impacts. We combined distinct organisational levels, covering biological biomarkers (histopathological and biochemical reactions in liver and fish gills), community based bioindicators (fish guilds, invertebrate metrics/traits and chironomid pupal exuviae) and ecosystem functional indicators (decomposition rates) to assess ecological status at designated Water Framework Directive monitoring sites, covering a gradient of human impact across several rivers in northern Portugal. We used Random Forest to rank the variables that contributed more significantly to successfully predict the different classes of ecological status and also to provide specific cut levels to discriminate each WFD class based on reference condition. A total of 59 Biological Quality Elements and functional indicators were determined using this procedure and subsequently applied to develop the integrated Multiple Ecological Level Index (MELI Index), a potentially powerful bioassessment tool.

First description of blaIMP-8 in a Pseudomonas mendocina isolated at the Hospital Infante D. Pedro, Aveiro, Portugal.

Pseudomonas mendocina carrying a novel class 1 integron containing an IMP-8 gene was isolated from an inanimate surface in a female ward sanitary facility of the Hospital Infante D. Pedro, Aveiro, Portugal. Hybridization with the integrase gene (intI1) and 16S rDNA revealed that the integron is chromosomally located. Here we report for the first time the presence of an IMP-8 metallo-beta-lactamase gene in the Pseudomonas genus.

A novel complex class 1 integron found in a Klebsiella pneumoniae isolate from Portugal.

Klebsiella pneumoniae Kp1 carrying a novel complex class 1 integron was isolated from an inanimate surface of a female ward sanitary facility in the Hospital Infante D. Pedro, Aveiro, central Portugal. The integron consists of two variable regions (VRs); VR1 was previously described in Escherichia coli and Vibrio cholerae, and VR2 contains an In37-like structure and is located downstream of an ISCR1 element. The integron was found on a plasmid of 225 kb. The qnrB10 gene, although present, is not associated with the complex class 1 integron.

Effects of a novel anticorrosion engineered nanomaterial on the bivalve Ruditapes philippinarum

Metallic corrosion is an unsolved problem that has been minimized through the application of specialized coatings containing corrosion inhibitors, such as 2-mercaptobenzothiazole (MBT). Recently, engineered nanomaterials (ENM), such as layered double hydroxides (LDH), have been used to immobilize or encapsulate those compounds promoting their controlled release in a more eco-friendly way. The present study aims to assess the toxicity of a novel anticorrosion nano-based solution (LDH loaded with MBT) and its major compounds separately (MBT and LDH) to the clam Ruditapes philippinarum, during a short-term exposure (96 h). The endpoints were lethality and changes in the physiological and biochemical parameters. MBT induced mortality (LC20 = 78.14 mg L−1) and significant physiological and biochemical changes. Globally, these effects were more severe than those treated with LDH and LDH–MBT that still induced significant biochemical effects. The present study demonstrated the eco-friendly properties of the immobilization process of the corrosion inhibitor in the nanoclays. Effects were observed at higher concentrations than those expected to occur in the environment and therefore these novel nanomaterials can be a promising anticorrosion material with low environmental hazard and risk.

Suitability of enzymatic markers to assess the environmental condition of natural populations of Gambusia affinis and Daphnia magna —a case study

In recent years, the use of biochemical markers, especially in the assessment of toxic effects and modes of action, under controlled laboratory conditions has increased. However, transposing their use to in situ monitoring or risk assessment evaluations has encountered barriers, mainly related to the difficulty in interpreting the meaning of biochemical variation. In this work, we aimed at understanding if biochemical marker activities (cholinesterase, glutathione S-transferase and lactate dehydrogenase) can be used to monitor the health status of natural populations of fish (Gambusia affinis) and daphnids (Daphnia magna). For that, two ponds with different water properties were chosen as study sites, and organisms collected at four sampling periods along the year. The pattern of biochemical marker responses was not the same in the two species, showing higher integrated biochemical marker response values in the winter for G. affinis and in the autumn for D. magna, suggesting specificities that must be taken into account in biomonitoring programmes by including representative species of several trophic levels. In the case of G. affinis, the differences in key physicochemical parameters between the two ponds (especially dissolved oxygen levels) did not seem to affect biochemical marker levels as if organisms were already perfectly adapted to their environment. In general, seasonal variation of water quality seems to have an important role on biochemical marker responses. Several parameters above Environmental Quality Standards were identified such as dissolved oxygen (DO), ammonia, nitrites, sulphides and metals, but eventual responses to these stressors could not be discriminated from natural variation except for particular cases.

Fulfilling spawning flow requirements for potamodromous cyprinids in a restored river segment

The Baixo Sabor hydroelectric scheme was recently constructed (began operating in 2015), blocking fish migration immediately at the river mouth. As a compensation measure for spawning habitat loss the Vilariça River which confluences with Sabor River, immediately downstream from the Baixo Sabor scheme, was chosen for rehabilitation site as an attempt to replace the spawning grounds lost in Sabor River for the potamodromous cyprinid Iberian barbel (Luciobarbus bocagei). Restoration activities included: placement of submerged weirs with fish ramps to increase the lotic/lentic sequence, bank reinforcement, boulder placement and river water profile increase. Water from the nearest reservoir was channeled underground to the lower Vilariça River in order to increase the water flow. The most appropriate volume of water was determined by means of a 1D model coupled with the CASiMiR to determine the weighted usable area for barbel spawners. Nine spawning grounds were identified. Fish migrations began in mid-April when water temperature increased (c. 16°C) and water flow decreased. Barbel tend to spawn in coarse substrate with shallow water and moderate current. Ontogenetic differences in habitat use were reported, with barbel juveniles preferring weaker currents and deeper zones when compared to spawners. Females also display different preferences, which are more apparent after spawning. Both life-stages exhibit the maximum habitat suitability at c. 1.5m3/s. The habitat model used in this study was able to accurately predict the occurrence of spawning grounds, representing, therefore, a valuable decision-making support tool for river managers.

Assessment of DNA damage in Ardea cinerea and Ciconia ciconia: A 5-year study in Portuguese birds retrieved for rehabilitation.

Over the past decades, the presence of micronucleated blood cells has been used to detect genotoxic effects of xenobiotics in fish, amphibians and birds. This study assessed the frequency of micronuclei (MN) and other nuclear abnormalities in erythrocytes of individuals of Ardea cinerea and Ciconia ciconia retrieved for rehabilitation in order to evaluate the influence of age, temporal and spatial factors on the occurrence of DNA damage in Portuguese wild birds. Blood smears from 65 birds with different life-history backgrounds (e.g. geographic origin, age) were collected between 2007 and 2011 and the frequency of erythrocyte nuclear abnormalities (ENAs) was analysed. Differences in DNA damage between ages were observed to occur in C. ciconia, with chicks displaying significantly higher frequencies of ENAs (both when looking at total ENAs or only MN frequency) than juveniles and adults. Additionally, significant differences in ENAs frequencies were observed between different years and geographic origins, whereas MN frequency alone did not show significant alterations concerning spatial and temporal variations. These results suggest that the assessment of ENAs rather than MN frequency alone may be a useful and valuable tool to complement the evaluation of DNA damage in populations of birds, as prompted by individual life-history traits and environmental factors.

Offspring Hg exposure relates to parental feeding strategies in a generalist bird with strong individual foraging specialization

Generalist species can potentially exploit a wide variety of resources, but at the individual level they often show a certain degree of foraging specialization. Specific foraging strategies, however, may increase exposure to environmental contaminants that can alter the cost-benefit balance of consuming particular food items. The Lesser Black-backed Gull (Larus fuscus) is known to opportunistically feed on a wide range of marine and terrestrial prey that differ in contaminant load, such as mercury (Hg) that strongly biomagnifies through the aquatic food web. The hypothesis tested in this study were: i) a predominant use of marine prey by females during egg-formation and by both parents during chick rearing increases the exposure to Hg during embryonic development and chick growth, and ii) this affects parental investment in clutch volume, chick growth and body condition. Total Hg burden and isotopic signatures of carbon (δ13C) and nitrogen (δ15N) were determined for eggs, down feathers, and primary feathers of L. fuscus chicks collected at a coastal colony in Belgium. As expected, eggs and feathers of chicks from parents with a stable isotope signature that suggested a predominantly marine diet had higher levels of Hg. The use of marine resources by females during the egg-formation period positively correlated to maternal investment in egg size, though entailing the cost of increased Hg-concentrations which in turn negatively affected clutch volume. Furthermore, it is shown that the use of chick down feathers is a suitable matrix to non-lethally estimate Hg concentrations in eggs. Contrary to our expectations, no relationship between Hg exposure and chick growth or chick body condition was found, which may be due the low concentrations found. We conclude that currently Hg contamination does not constitute a risk for development and condition of L. fuscus offspring at the levels currently observed at the Belgian coast.