Optical fiber immunosensors based on surface plasmon resonance for the detection of Escherichia coli.

Every year, millions of people suffer some form of illness associated with the consumption of contaminated food. Escherichia coli (E. coli), found in the intestines of humans and other animals, is commonly associated with various diseases, due to the existence of pathogenic strains. Strict monitoring of food products for human consumption is essential to ensure public health, but traditional cell culture-based methods are associated with long waiting times and high costs. New approaches must be developed to achieve cheap, fast, and on-site monitoring. Thus, in this work, we developed optical fiber sensors based on surface plasmon resonance. Gold and cysteamine-coated fibers were functionalized with anti-E. coli antibody and tested using E. coli suspensions with concentrations ranging from 1 cell/mL to 105 cells/mL. An average logarithmic sensitivity of 0.21 ± 0.01 nm/log(cells/mL) was obtained for three independent assays. An additional assay revealed that including molybdenum disulfide resulted in an increase of approximately 50% in sensitivity. Specificity and selectivity were also evaluated, and the sensors were used to analyze contaminated water samples, which verified their promising applicability in the aquaculture field.

Ecotoxicological evaluation of effluent from bovine slaughterhouses disinfected by peracetic acid (PAA) using the bioindicator Girardia tigrina.

The evaluation of the ecotoxicological effects of the effluent after treatment with peracetic acid is relevant to help establish reference concentrations for the disinfection process and waste recovery. Therefore, the objective of this work was to evaluate the ecotoxicity of effluent from a bovine slaughterhouse treated with peracetic acid on Girardia tigrina. The toxicity bioassays for planaria were the acute test (LC50) and chronic assays: locomotion, regeneration, reproduction and fertility. The results showed that the effluent treated with peracetic acid showed less toxicity than the effluent without application of peracetic acid. The effluent after peracetic acid application showed a chronic toxic effect in the reduction of locomotor speed in all studied disinfectant concentrations (0.8, 1.6, 3.3 and 6.6 µg L-1 of peracetic acid) and a delay in the formation of G. tigrina photoreceptors at the concentration of 6.6 µg L-1 of peracetic acid. Peracetic acid concentrations of 0.8, 1.6 and 3.3 µg L-1 were not toxic for blastema regeneration, photoreceptor and auricle formation, fecundity and fertility. In addition, this study assists in defining doses of peracetic acid to be recommended in order to ensure the wastewater disinfection process without causing harm to aquatic organisms.

Multi-generation effects of lead (Pb) on two Daphnia species.

Two monophyletic Daphnia species (Daphnia magna and D. similis) were exposed to a sub-lethal concentration of Pb (50 µg/L) for nine generations under two food regimes (usual and restricted) and analyzed for acetylcholinesterase (AChE) activity, first reproduction delay, lifespan, and net reproductive rate (R0) at the subcellular, individual, and population levels, respectively. In the sixth generation, Pb-acclimated neonates were moved to clean media for three more generations to check for recovery. The net reproductive rate (R0) of D. magna was not affected by Pb. However, Pb stimulated reproduction, reduced lifespan, and decreased AChE activity. First reproduction delay and lifespan did not improve during the recovery process, suggesting a possible genetic adaptation. Food restriction reduced R0, lifespan, delayed hatching, and increased AChE activity; the opposite outcomes were observed for D. similis. The full recovery shown by R0 suggests the physiological acclimation of D. similis. Under food restriction, the animals exhibited a reduction of R0 and lifespan, delayed first reproduction, and increased AChE activity; however, there was no effect of Pb. The recovery process under food restriction showed that D. similis might not cope with Pb exposure, indicating a failed recovery. Such outcomes indicate that one model species' sensitivity may not represent another's sensitivity.

The role of warming in modulating neodymium effects on adults and sperm of Mytilus galloprovincialis.

The use of rare earth elements (REEs) has been increasing and one of the most used is neodymium (Nd). Being an emergent contaminant, its negative impacts are poorly understood. Aquatic organisms are also threatened by climate change-related factors, as is the case of warming, which can change the effects of REEs. Thus, the impacts of Nd, warming, and the combination of both stressors were studied in adult mussels and sperm of the species Mytilus galloprovincialis, after an exposure period of 28 days (adults) and 30 min (sperm). The effects were evaluated through the analysis of biochemical and histopathological alterations in adults and biochemical and physiological responses given by sperm. The results showed that mussels only activated their biotransformation capacity when exposed to the stressors acting alone, which was insufficient to avoid lipid peroxidation. Furthermore, warming (alone and combined with Nd) also produces damage to proteins. The digestive gland was the most sensitive organ to Nd, presenting several histopathological alterations. In the case of sperm, all stressors induced lipid peroxidation, a higher oxygen demand, and a decrease in velocity, even if the sperm viability was maintained. It seems that warming influenced the effects of Nd to some extent. The present findings contribute significantly to the field of REEs environmental toxicology by offering valuable insights into the impacts of Nd on various biological levels of mussels. Additionally, within the context of climate change, this study sheds light on how temperature influences the effects of Nd. The obtained results indicate that both stressors can potentially compromise the overall health of mussel populations, thereby affecting other species reliant on them for food and habitat. Moreover, this study highlights impaired sperm health, which could adversely affect their reproductive capacity and ultimately lead to population decline.

Holistic assessment of dimethoate toxicity in Carcinus aestuarii's muscle tissues.

Dimethoate (DMT) is one of the most harmful and commonly used organophosphate pesticides in agricultural lands to control different groups of parasitic insects. However, this pesticide is considered a dangerous pollutant for aquatic organisms following its infiltration in coastal ecosystems through leaching. Yet, our investigation aimed to gain new insights into the toxicity mechanism of DMT in the muscles of the green crab Carcinus aestuarii, regarding oxidative stress, neurotransmission impairment, histological aspects, and changes in lipid composition, assessed for the first time on the green crab's muscle. Specimens of C. aestuarii were exposed to 50, 100, and 200 µg DMT L-1 for 24 h. Compared to the negative control group, the higher the DMT concentration, the lower the saturated fatty acids (SFA), and the higher the monounsaturated fatty acids (MUFA). The significant increase in polyunsaturated fatty acid n-6 (PUFA n-6) was related to the high release, mainly, of linoleic acid (LA, C18: 2n6) and arachidonic acid (ARA, C20: 4n6) levels. Biochemical biomarkers showed that DMT exposure promoted oxidative stress, highlighted by increased levels of hydrogen peroxide (H2O2), malondialdehyde (MDA), advanced oxidation protein product levels (AOPP), and protein carbonyl (PCO). Furthermore, the antioxidant defense system was activated, as demonstrated by the significant changes in the enzymatic activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and reduced glutathione (GSH) levels associated with an adaptation process of C. aestuarii to cope with the DMT exposure. This pesticide significantly impairs the neurotransmission process, as evidenced by the inhibition of acetylcholinesterase (AChE) activity. Finally, several histopathological changes were revealed in DMT-treated crabs, including vacuolation, and muscle bundle loss.This research offered new insights into the toxic mechanism of DMT, pointing to the usefulness of fatty acid (FA) composition as a sensitive biomarker in littoral crabs.

What does not kill it makes it stronger! The tolerance of the F1 larvae of Chironomus xanthus to a neonicotinoid insecticide formulation.

Thiamethoxam (TMX) is a systemic neonicotinoid that acts as a partial agonist of the nicotinic acetylcholine receptors (nAChRs). However, target species have shown resistance to formulations based on such neonicotinoids, which can also be expected for non-target insects. This research aimed to study the effects of a formulation based on TMX [Cruiser® 350 FS (CRZ)] on the life traits of Chironomus xanthus filial generation (F1) and compare it with the parental generation (P). Environmentally relevant concentrations of CRZ significantly decreased larvae growth P generation , also slowing and decreasing their emergence. Larvae of the F1 generation were less sensitive than their parents, suggesting that the progeny were able to thrive and perform basic physiological functions better than the parental generation. Our results highlight that insect resistance to neonicotinoids may be associated with the better performance of the filial generation, which is related to the change in affinities of the active ingredient for the sub-units constituting the nAChRs subtypes of F1 organisms, inherited from P organisms that were able to survive and reproduce. Moreover, further studies using biochemical and omics tools should be performed to disentangle the specific changes occurring at the nAChRs throughout insect development.

Impact of Sea Warming and 17-α-Ethinylestradiol Exposure on the Lipid Metabolism of Ruditapes philippinarum Clams.

This paper reports on an NMR metabolomics study of lipophilic extracts of Ruditapes philippinarum clams exposed to the hormonal contaminant 17-α-ethinylestradiol (EE2), at 17 °C and 21 °C. The results reveal that exposure at 17 °C triggers a weak response at low EE2 concentrations, suggestive of a slight increase in membrane rigidity, followed by lipid metabolic stability at higher EE2 concentrations. On the other hand, at 21 °C, lipid metabolism begins to respond at 125 ng/L EE2, with antioxidant docosahexaenoic acid (DHA) helping to tackle high-oxidative-stress conditions, in tandem with enhanced storage of triglycerides. Exposure to 625 ng/L EE2 (highest concentration) enhances phosphatidylcholine (PtdCho) and polyunsaturated fatty acid (PUFA) levels, their direct intercorrelation suggesting PUFA incorporation in new membrane phospholipids. This should lead to increased membrane fluidity, probably aided by a decrease in cholesterol. PUFA levels, considered a measure of membrane fluidity, were strongly (and positively) correlated to intracellular glycine levels, thus identifying glycine as the main osmolyte entering the cells under high stress. Membrane fluidity also seems to elicit the loss of taurine. This work contributes to the understanding of the mechanisms of response of R. philippinarum clams to EE2 in tandem with warming while unveiling novel potential markers of stress mitigation, namely high levels of PtdCho, PUFAs (or PtdCho/glycerophosphocholine and PtdCho/acetylcholine ratios) and linoleic acid and low PUFA/glycine ratios.

Mapping Africa's Biodiversity: More of the Same Is Just Not Good Enough.

Species distribution data are fundamental to the understanding of biodiversity patterns and processes. Yet, such data are strongly affected by sampling biases, mostly related to site accessibility. The understanding of these biases is therefore crucial in systematics, biogeography, and conservation. Here we present a novel approach for quantifying sampling effort and its impact on biodiversity knowledge, focusing on Africa. In contrast to previous studies assessing sampling completeness (percentage of species recorded in relation to predicted), we investigate whether the lack of knowledge of a site attracts scientists to visit these areas and collect samples of species. We then estimate the time required to sample 90% of the continent under a Weibull distributed biodiversity sampling rate and the number of sampling events required to record $ \ge $50% of the species. Using linear and spatial regression models, we show that previous sampling has been strongly influencing the resampling of areas, attracting repeated visits. This bias has existed for over two centuries, has increased in recent decades, and is most pronounced among mammals. It may take between 172 and 274 years, depending on the group, to achieve at least one sampling event per grid cell in the entire continent. Just one visit will, however, not be enough: in order to record $ \ge $50% of the current diversity, it will require at least 12 sampling events for amphibians, 13 for mammals, and 27 for birds. Our results demonstrate the importance of sampling areas that lack primary biodiversity data and the urgency with which this needs to be done. Current practice is insufficient to adequately classify and map African biodiversity; it can lead to incorrect conclusions being drawn from biogeographic analyses and can result in misleading and self-reinforcing conservation priorities. [Amphibians; birds; mammals; sampling bias; sampling gaps; Wallacean shortfall.].

How temperature rise will influence the toxic impacts of 17 α-ethinylestradiol in Mytilus galloprovincialis?

Pharmaceutical drugs are Contaminants of Emerging Concern (CECs) and are continuously discharged into the environment. As a result of human and veterinary use, these substances are reaching aquatic coastal systems, with limited information regarding the toxic effects of these compounds towards inhabiting organisms. Among CECs are pharmaceuticals like 17 α-ethinylestradiol (EE2), which is a synthetic hormone with high estrogenic potency. EE2 has been increasingly found in different aquatic systems but few studies addressed its potential toxicity to marine wildlife, in particular to bivalves. Therefore, the aim of the present study was to evaluate the influence of temperature (17 °C-control and 21 °C) on the potential effects of EE2 on the mussel Mytilus galloprovincialis. For this purpose, mussels were exposed to different concentrations of EE2 (5.0; 25.0; 125.0 and 625 ng/L), resembling low to highly polluted sites. Mussels exposed to each concentration were maintained under two temperatures, 17 and 21 °C, which represent actual and predicted warming conditions, respectively. After 28 days, oxidative stress status, metabolism related parameters, neurotoxicity and histopathological alterations were measured. The results obtained clearly showed an interactive effect of increased temperature and EE2, with limited antioxidant and biotransformation capacity when both stressors were acting together, leading to higher cellular damage. The combination of both stressors also enhanced mussels' metabolic capacity and neurotoxic effects. Nevertheless, loss of redox balance was confirmed by the strong decrease of the ratio between reduce glutathione (GSH) and oxidized glutathione (GSSG) in contaminated mussels, regardless the temperature. Histopathological indexes in contaminated mussels were significantly different from the control group, indicating impacts in gills and digestive glands of mussels due to EE2, with higher values observed at 21 °C. Overall, this study demonstrates that of EE2 represents a threat to mussels and predicted warming conditions will enhance the impacts, which in a near future might result in impairments at the population and community levels.

Combined effects of polyethylene microplastics and natural stressors on Chironomus riparius life-history traits.

Several studies have shown that ingestion of microplastics causes adverse effects in aquatic organisms, including sediment-dwelling invertebrates. Most studies focus on evaluating the effects of plastic particles alone without testing the mediating effects of different natural stressors and thus lacking realistic exposure scenarios. The present study addresses the interactive effects of exposure to polyethylene microplastics (PE-MPs; 2.5 g/kg) in the midge Chironomus riparius life history traits under different temperatures (15, 20 and 25 °C), a salinity gradient (0, 1 and 3 g L-1 sodium chloride - NaCl) and different levels of food (0.5, 0.25 and 0.125 mg macerated fish food larva-1day-1). By the analyses of linear models and independent action models applied to different life-history traits, such as larval growth, development time and imagoes body weight, the present work reveals that under temperatures lower than 20 °C or severe food shortage (<0.25 mg macerated fish food larva-1day-1), microplastics' effects can be stronger than those observed at standard toxicity test conditions (20 °C and 0.5 mg food larva-1day-1). Additionally, we also found that, in general, toxicity induced by PE-MPs to C. riparius larvae was reduced under warmer temperature (25 °C) and salinity. As observed, MPs toxicity can be mediated by natural stressors, which underlines the importance of co-exposure studies. In this sense, these results contribute to a more accurate risk assessment of microplastics. Despite the complex interactions between microplastics and natural factors here tested, were not found evidence that the deleterious effects of PE-MPs on C. riparius life cycle history are aggravated under increased temperature, food shortage, or salinisation of freshwaters.

The multigenerational effects of clothianidin on Chironomus xanthus: Larvae exposed to this acetylcholine super agonist show no clear resistance.

Clothianidin (CLO) is an insecticide belonging to the second-generation class of neonicotinoids. In this study, we evaluated how CLO affects the survival and the complete life cycle of the tropical insect Chironomus xanthus, a non-target species, considering the Parental (P) and Filial (F1) generations. We found a 48 h-lethal concentration (LC50) of CLO of 3.78 µg/L. The lowest observed effect concentrations (LOECs) were: i) for body growth and head capsule width in P generation = 47.3 ng/L CLO; ii) for body growth and head capsule width in F1 generation larvae = 80 and 36.4 ng/L CLO, respectively; iii) for cumulative emergence it was 80 ng/L CLO in the P generation, while there was no significant difference in the F1 generation; iv) for total developmental time for males and females = 61.53 ng/L in P generation; v) in the F1 generation, the LOEC was determined to be 36.4 ng/L for males and 80 ng/L for females; vi) The number of total hatched eggs and total hatched eggs/female had LOECs of 36.4 ng/L CLO for both generations. Our study reveals that environmentally relevant concentrations of the CLO-based insecticide are highly toxic to C. xanthus. It also shows that the F1 generation, resulting from parents exposed to CLO was not clearly resistant to the insecticide. This fact might be explained by the different effects observed for males and females of F1 generation. Understanding the sub-types of acetylcholine receptors present on target and non-target insect species and toxicological effects of neonicotinoids seems to be desirable for the insecticide industry to deal with insect pests and the environmental protection of non-target organisms.

Effects of Carbamazepine in Bivalves: A Review.

Carbamazepine (CBZ) is among the ten most frequent pharmaceuticals that occur in the aquatic systems, with known effects on inhabiting organisms, including bivalves. Bivalves are important species in coastal ecosystems, often exhibiting a dominant biomass within invertebrate communities. These organisms play a major role in the functioning of the ecosystem and particularly in food webs (as suspension-feeders) and represent a significant fraction of the fisheries resource. They also have strong interactions with the environment, water and sediment and are considered good bioindicator species. The present paper reviews the known literature on the impacts of CBZ in biological endpoints of marine bivalves exposed to environmentally and non-environmentally relevant concentrations, highlighting differences in terms of biological responses, associated with exposure period, concentrations tested, and species used. Overall, the literature available showed that CBZ induces individual and sub-individual effects in marine bivalves (adults and life stages) and the most common effect reported was the induction of oxidative stress.

How do life-history traits influence the fate of intertidal and subtidal Mytilus galloprovincialis in a changing climate?

Coastal organisms (i.e. intertidal or upper subtidal species) live in between the terrestrial and aquatic realms, making them particularly vulnerable to climate change. In this context, intertidal organisms may suffer from the predicted sea level rise (increasing their submerged time) while subtidal organisms may suffer from anthropically-induced hypoxia and its consequences. Although there is some knowledge on how coastal organisms adapt to environmental changes, the biochemical and physiological consequences of prolonged submergence periods have not yet been well characterized. Thus, the present study aimed to assess the biochemical alterations experienced by intertidal organisms maintained always under tidal exposure (IT); intertidal organisms maintained submersed (IS); subtidal organisms maintained always submersed (SS); subtidal organisms under tidal exposure (ST). For this, Mytilus galloprovincialis specimens from contiguous intertidal and subtidal populations were exposed to the above mentioned conditions for twenty-eight days. Results indicated that both intertidal and subtidal mussels are adapted to the oxidative stress pressure caused by tidal and submerged conditions tested. Intertidal mussels did not seem to be negatively affected by submergence while ST specimens were energetically challenged by tidal exposure. Both IT and ST mussels consumed glycogen to fuel up mechanisms aiming to maintain redox homeostasis. Overall, both intertidal and subtidal populations were capable of coping with tidal exposure, although the strategies employed differed between them. These findings indicate that although IT mussels may not significantly suffer from the longer-term submergence, hypoxic events occurring in the context of global warming and other anthropogenic impacts may have consequences on both IT and ST populations. Altogether, it is important to highlight that tides may act as a confounding factor in experiments concerning coastal organisms, as it causes additional physiological and biochemical perturbations.

How temperature can alter the combined effects of carbon nanotubes and caffeine in the clam Ruditapes decussatus?

Nowadays, multi-walled carbon nanotubes are considered to be emerging contaminants and their impact in ecosystem has drawn special research attention, while other contaminants, such as caffeine, have more coverage in literature. Despite this, the effects of a combination of the two has yet to be evaluated, especially considering predicted temperature rise. In the present study a typical bioindicator species for marine environment, the clam Ruditapes decussatus, and classical tools, such as biomarkers and histopathological indices, were used to shed light on the species' response to these contaminants, under actual and predicted warming scenarios. The results obtained showed that both contaminants have a harmful effect at tissue level, as shown by higher histopathological index, especially in digestive tubules. Temperatures seemed to induce greater biochemical impacts than caffeine (CAF) and -COOH functionalized multi-walled carbon nanotubes (f-MWCNTs) when acting alone, namely in terms of antioxidant defences and energy reserves content, which were exacerbated when both contaminants were acting in combination (MIX treatment). Overall, the present findings highlight the complex response of clams to both pollutants, evidencing the role of temperature on clams' sensitivity, especially to mixture of pollutants.

How Ulva lactuca can influence the impacts induced by the rare earth element Gadolinium in Mytilus galloprovincialis? The role of macroalgae in water safety towards marine wildlife.

Rare earth elements (REEs) are gaining growing attention in environmental and ecotoxicological studies due to their economic relevance, wide range of applications and increasing environmental concentrations. Among REEs, special consideration should be given to Gadolinium (Gd), whose wide exploitation as a magnetic resonance imaging (MRI) contrast agent is enhancing the risk of its occurrence in aquatic environments and impacts on aquatic organisms. A promising approach for water decontamination from REEs is sorption, namely through the use of macroalgae and in particular Ulva lactuca that already proved to be an efficient biosorbent for several chemical elements. Therefore, the present study aimed to evaluate the toxicity of Gd, comparing the biochemical effects induced by this element in the presence or absence of algae. Using the bivalve species Mytilus galloprovincialis, Gd toxicity was evaluated by assessing changes on mussels' metabolic capacity and oxidative status. Results clearly showed the toxicity of Gd but further revealed the capacity of U. lactuca to prevent injuries to M. galloprovincialis, mainly reducing the levels of Gd in water and thus the bioaccumulation and toxicity of this element by the mussels. The results will advance the state of the art not only regarding the effects of REEs but also with regard to the role of algae in accumulation of metals and protection of aquatic organisms, generating new insights on water safety towards aquatic wildlife and highlighting the possibility for resources recovery.

Lumbriculus variegatus (oligochaeta) exposed to polyethylene microplastics: biochemical, physiological and reproductive responses.

Freshwater sediments are a repository of microplastics (MPs) resulting from inland anthropogenic activities. Benthic invertebrates, particularly endobenthic sediment-ingesting species such as the annelid Lumbriculus variegatus (blackworm), are commonly found in contaminated sediments where they likely find and ingest MPs. In the present study, L. variegatus was exposed to concentrations between 0.51 and 20 g kg-1 dry sediment of four size-classes of irregularly-shaped polyethylene MPs (PE-MPs; size-class A: 32-63, B: 63-125, C: 125-250 and D: 250-500 µm) for 48 h to assess their sub-cellular responses to particles ingested, and for 28 days to determine chronic effects on worm's reproduction and biomass. After the short-term exposure (48 h), number of PE-MPs in blackworms' gut were related to MPs concentration in the sediment. In general, PE-MPs ingestion by blackworms induced depletion of their energy reserves (e.g., sugars in all size classes and lipids in the size-classes of PE-MPs > 125 µm), concomitant with the activation of antioxidant and detoxification mechanisms (increased level of total glutathione in all size-classes, and increased glutathione-S-transferase activity in PE-MPs > 250 µm), preventing lipid peroxidation. In addition, it was observed a reduction of aerobic energy production (decreased activity of the electron transport system) and a slight increase in neurotransmission (cholinesterase activity). After a long-term exposure (28 d), the presence and ingestion of PE-MPs did not affect reproduction and biomass of L. variegatus. The activation and efficiency of the antioxidant and detoxification mechanisms allied with the anatomy and physiology of L. variegatus, its feeding strategy and potentially dynamic ingestion/egestion capacity seem to be key features preventing MP deleterious effects under short- and chronic-exposures. Considering the MPs levels reported for freshwater sediments, and despite evidence of MPs ingestion and some sub-organismal effects, our results suggest no adverse impacts of PE-MPs contamination on L. variegatus populations fitness. This study applies an integrative approach in which data concerning the ingestion of different sized MPs and subsequent sub-cellular and apical responses are delivered, raising knowledge on endobenthic invertebrates' strategies to potentially overcome MP toxicity in field contaminated sites.

Differential accumulation of PAHs within planarian cephalic and posterior body parts.

It has been observed that freshwater planarians can accumulate cadmium in their head portions, with neurotoxicity and head loss accompanying this phenomenon. Since planarians exhibit head loss and symptoms of neurotoxicity in response to PAHs, we investigated the differential accumulation of pyrene and B[a]P in the body and head portions of Girardia tigrina, a freshwater planarian. It is evidenced that planarian head fragments present higher amounts of pyrene- and B[a]P-equivalents than body fragments, indicating a differential distribution of these compounds within planarian tissues.

Gut and faecal bacterial community of the terrestrial isopod Porcellionides pruinosus: potential use for monitoring exposure scenarios.

This work aimed to characterize the gut and faeces bacterial communities (BC) of Porcellionides pruinosus using high-throughput sequencing. Isopods were collected from the field and kept in laboratory conditions similar to those normally applied in ecotoxicology tests. Faeces and purged guts of isopods (n = 3 × 30) were analysed by pyrosequencing the V3-V4 region of 16 S rRNA encoding gene. Results showed that gut and faecal BCs were dominated by Proteobacteria, particularly by an OTU (Operational Taxonomic Unit) affiliated to genus Coxiella. Diversity and richness values were statistically higher for faecal BC, mainly due to the occurrence of several low-abundance phylotypes. These results may reflect faecal carriage of bacterial groups that cannot settle in the gut. BCs of P. pruinosus comprised: (1) common members of the soil microbiota, (2) bacterial symbionts, (3) bacteria related to host metabolic/ecological features, and (4) bacterial etiological agents. Comparison of BC of this isopod species with the BC from other invertebrates revealed common bacterial groups across taxa. The baseline information provided by this work will assist the design and data interpretation of future ecotoxicological or biomonitoring assays where the analysis of P. pruinosus BC should be included as an additional indicator. CAPSULE: Terrestrial isopods bacterial communities might support ecotoxicological assays and biomonitoring processes as a valuable tool.

Physiological and Biochemical Effects of Cd Stress in Thlaspi Arvense L-A Non-Accumulator of Metals.

The field pennycress (Thlaspi arvense L.) is a sensitive non-accumulator of metals. The main objective of the present work was to evaluate the effects of Cd stress in T. arvense using a physiological approach. Four-week-old plants were exposed to increasing concentrations of Cd (0, 10, 50 and 100 µM Cd(NO3)2) for 14 days. Plants were harvested at days 0, 3, 7 and 14 to assess the following parameters: shoot and root length and fresh weight; osmolality and conductivity in leaves; chlorophyll a and b contents and photosynthetic efficiency in leaves (young and expanded); water content, Cd accumulation and nutrient imbalances in leaves (young and expanded) and roots. Thlaspi arvense presented a reduction of 27% in the length of roots exposed to 100 µM Cd, and in plants exposed to 50 and 100 µM Cd, a reduction in the fresh weight of both shoots (53 and 58%, respectively) and roots (58 and 63%, respectively) was observed. In general, in plants exposed to the highest concentrations of Cd, a decrease in leaves osmolality and membrane permeability and in water content of both roots and leaves were observed, as well as several nutrient imbalances. As for the photosynthetic parameters, young and expanded leaves responded differently to Cd stress. Exposed young leaves presented no alterations in photosynthetic efficiency or chlorophyll contents, while expanded leaves of 100 µM Cd-treated plants showed a reduction of up to 67% in chlorophyll contents and a concomitant reduction of 30% in photosynthetic efficiency. Overall, Cd-induced senescence in the non-accumulator plant T. arvense exposed to high concentrations of Cd, which was measured as a decrease in several physiological and biochemical parameters and nutrient imbalances. These Cd-induced alterations resulted in lower plant growth, which might have further implications on plant performance at the population level.

Concentrations levels and effects of 17alpha-Ethinylestradiol in freshwater and marine waters and bivalves: A review.

Pharmaceutical drugs are contaminants of emerging concern and are amongst the most frequent in the aquatic environment. Even though a vast literature indicate that pharmaceuticals exert negative impacts towards aquatic organisms, mainly in vertebrates, there is still limited information regarding the effects of these drugs in freshwater and marine bivalves. Marine bivalves have a high ecological and socio-economic value and are considered good bioindicator species in ecotoxicology and risk assessment programs. Furthermore, another lacking point on these studies is the absence of bioconcentration data, with no clear relationship between the concentration of drugs on tissue and the biological effects. 17alpha-ethinylestradiol (EE2) is a synthetic hormone with high estrogenic potency that was added to the Watch List adopted by the European Commission stating the priority substances to be monitored. Thus, this review summarizes the current knowledge on the concentration levels and effects of EE2 on freshwater and marine bivalves. The inclusion in the Watch List, the presence in freshwater and marine systems, and the impact exerted on aquatic biota, even at trace concentrations, justify the review devoted to this pharmaceutical drug. Globally the available studies found that EE2 induces individual and sub-individual (e.g. tissue, cellular, biochemical and molecular levels of biological organization) impacts in bivalves. Essentially, this estrogenic compound, even in trace concentrations, was found to have accumulated in wild and laboratory exposed bivalves. The most common effects reported were changes on the reproductive function and energy metabolism. The studies used in this review support keeping the EE2 on the Watch List and highlight the need to increase the number of monitorization studies since clear negative effects were exerted on bivalves by this drug.