Isabel Peres

Biological treatment of the effluent from a bleached kraft pulp mill using basidiomycete and zygomycete fungi

Three white-rot fungi (Pleurotus sajor caju, Trametes versicolor and Phanerochaete chrysosporium) and one soft-rot fungi (Rhizopus oryzae) species confirmed their potential for future applications in the biological treatment of effluents derived from the secondary treatment of a bleached kraft pulp mill processing Eucalyptus globulus. Among the four species P. sajor caju and R. oryzae were the most effective in the biodegradation of organic compounds present in the effluent, being responsible for the reduction of relative absorbance (25-46% at 250 nm and 72-74% at 465 nm) and of chemical oxygen demand levels (74 to 81%) after 10 days of incubation. Laccase (Lac), lignin (Lip) and manganese peroxidases (MnP) expression varied among fungal species, where Lac and LiP activities were correlated with the degradation of organic compounds in the effluent treated with P. sajor caju. The first two axes of a principal component analysis explained 88.9% of the total variation among sub-samples treated with the four fungus species, after different incubation periods. All the variables measured contributed positively to the first component except for the MnP enzyme activity which was the only variable contributing negatively to the first component. Absorbances at 465 nm, LiP and Lac enzyme activities were the variables with more weight on the second component. P. sajor caju revealed to be the only species able to perform the biological treatment without promoting an increment in the toxicity of the effluent to the Vibrio fischeri, as it was assessed by the Microtox assay. The opposite was recorded for the treatments with the other three species of fungus. EC(50-5 min) values ranging between 28 and 57% (effluent concentrations) were recorded even after 10 to 13 days of treatment with P. chrysosporium, R. oryzae or with T. versicolor.

Effects of diamond nanoparticle exposure on the internal structure and reproduction of Daphnia magna

Nanomaterials have significant technological advantages but their release into the environment also carry potential ecotoxicological risks. Carbon-based nanoparticles and particularly diamond nanoparticles have numerous industrial and medical applications. The aim of the present study was to evaluate the toxic effects of diamond nanoparticles with an average particle size of 20 nm on the survival, reproduction and tissue structure of the freshwater crustacean Daphnia magna. The chronic toxicity test results showed 100% mortality at concentrations higher than 12.5 mg l(-1) and that reproduction inhibition occurred in concentrations higher than 1.3 mg l(-1). Light microscopy showed that diamond nanoparticles adhere to the exoskeleton surface and accumulate within the gastrointestinal tract, suggesting that food absorption by the gut cells may be blocked. The results support the use of chronic approaches in environmental protection as part of an integrated environmental monitoring and assessment strategy.

Assessing the estrogenic potency in a Portuguese wastewater treatment plant using an integrated approach

The estrogenic potency of a wastewater treatment plant (WWTP) was evaluated using chemical and biological analyses, which showed that after the station treatment processes some of the selected endocrine disruptor compounds (EDCs) were still present in the treated effluent (e.g., bisphenol A, alkylphenols, estrone). Thus, the most common endocrine EDCs were identified and quantified and the overall estrogenicity of the treated effluent assessed by integrating the results. Male goldfish (Carassius auratus) were used as biological indicators in a 28-day experiment. Vitellogenin (Vtg), gonadosomatic and hepatosomatic indices, steroids (17beta-estradiol and 11-ketotestosterone) and histopathology were biomarkers used in fish to evaluate WWTP treated effluent estrogenicity, in combination with instrumental analyses. The results showed a significant increase (P < 0.01) in plasma and liver Vtg, which were significantly correlated (r = 0.66; P < 0.01). The gonadosmatic index was significantly (P < 0.01) reduced in exposed fish. The steroid analyses revealed significant elevations in 17beta-estradiol and depressed 11-ketotestosterone concentrations. The histological examinations show changes in exposed fish gonads, such as regressed testes and in some cases (43% to 75%) the development of ovo-testis in fish exposed to 50% and 100% treated effluent.

Metallothionein responses in the Asiatic clam (Corbicula fluminea) after exposure to trivalent arsenic

Abstract The main objective of this work was to evaluate arsenic effects on metallothionein (MT) induction by exposing a freshwater Asiatic clam (Corbicula fluminea) to different concentrations of this metalloid. The presence of MT-like proteins was detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis and compared with a standard rabbit MT. In addition, the polarographic response showed good correspondence between standard MT and MT-like curves from C. fluminea, allowing MT quantification. The results show that clams exposed to different concentrations of arsenic are able to induce significant levels of MTs. Although variability was found in MT induction, significant differences in MT levels were found after 28 days of exposure in all treatments in comparison with the controls, suggesting that exposure to arsenic induced MT-like proteins in C. fluminea.

Liver Alterations in Two Freshwater Fish Species ( Carassius auratus and Danio rerio ) Following Exposure to Different TiO 2 Nanoparticle Concentrations

The toxicity of titanium dioxide nanoparticles (TIO₂ NPs) and oxidative stress effects were studied in two freshwater fish species (Carassius auratus and Danio rerio) exposed for 21 days to different concentrations (0.01, 0.1, 1, 10, 100/mgL) of TiO₂ NPs and to a control (tap water). Additional fish were transferred to clean water for 14 days to assess the ability to recover from exposure to TiO₂ NPs. Activities of the enzyme glutathione-S-transferase (GST) and lipid peroxidation (LPO) (malondialdheyde) were measured as indicators of oxidative stress. Histological and ultra-structural changes in livers from both species of fish were evaluated by light and electron microscopy. Results show a general GST activity increase according to TiO₂ NPs concentrations, which is in agreement with data from LPO. After 21 days, GST activities decreased possibly caused by suppression of GST synthesis as a result of severe stress. Histological and ultra-structural analysis of livers from exposed fish show degeneration of the hepatic tissue and alterations in hepatocytes such as glycogen depletion and an increase in lipofucsin lysosome-like granules. After a depuration period a partial recovery for biochemical markers and cells was observed. The results suggest that TiO₂ promotes alterations in hepatic tissues compatible with oxidative stress.

A multi-integrated approach on toxicity effects of engineered TiO2 nanoparticles

The new properties of engineered nanoparticles drive the need for new knowledge on the safety, fate, behavior and biologic effects of these particles on organisms and ecosystems. Titanium dioxide nanoparticles have been used extensively for a wide range of applications, e.g, self-cleaning surface coatings, solar cells, water treatment agents, topical sunscreens. Within this scenario increased environmental exposure can be expected but data on the ecotoxicological evaluation of nanoparticles are still scarce. The main purpose of this work was the evaluation of effects of TiO2 nanoparticles in several organisms, covering different trophic levels, using a battery of aquatic assays. Using fish as a vertebrate model organism tissue histological and ultrastructural observations and the stress enzyme activity were also studied. TiO2 nanoparticles (Aeroxide® P25), two phase composition of anatase (65%) and rutile (35%) with an average particle size value of 27.6±11 nm were used. Results on the EC50 for the tested aquatic organisms showed toxicity for the bacteria, the algae and the crustacean, being the algae the most sensitive tested organism. The aquatic plant Lemna minor showed no effect on growth. The fish Carassius auratus showed no effect on a 21 day survival test, though at a biochemical level the cytosolic Glutathione-S-Transferase total activity, in intestines, showed a general significant decrease (p<0.05) after 14 days of exposure for all tested concentrations. The presence of TiO2 nanoparticles aggregates were observed in the intestine lumen but their internalization by intestine cells could not be confirmed.

Impact of a secondary treated bleached Kraft pulp mill effluent in both sexes of goldfish (Carassius auratus L.)

The aim of the present study was to assess the toxic effects of a secondary treated effluent from a modern pulp mill processing Eucalyptus globulus on both sexes of goldfish. The effects in the exposed fish were investigated by measuring biomarkers which have been used to assess the effects of BKME on aquatic biota, with particular emphasis in fish. However, few studies have been focused on effluents from pulp mill plants processing eucalyptus. The relative proportion of cytochrome P450 (CYP1A) and vitellogenin (VTG) induction were analyzed in the livers of males and females goldfish, exposed to different concentrations of a bleached Kraft pulp mill (BKPM) effluent. Somatic indices such as HSI (hepatosomatic index) and GSI (gonadosomatic index) were calculated and a significant reduction was found in males GSI. A significant increase of HSI was recorded for both sexes exposed to 50% BKPM effluent. Exposure to BKPM effluent induced CYP1A synthesis in both sexes and decreased VTG synthesis in females according to the different effluent concentrations suggesting that the secondary treated effluent contained compounds that affect fish negatively. The results suggest that BKPM effluent can cause sex-related biochemical changes in xenobiotic metabolism.

Sea warming affects bream (Sparus aurata) tissues and stress proteins (HSP70)

***** and M.S. Diniz* *REQUIMTE, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Centro de Quimica Fina e Biotecnologia, Universidade Nova de Lisboa, 2829-516 Caparica. **Laboratorio Maritimo da Guia, Centro de Oceanografia, Faculdade de Ciencias da Universidade de Lisboa, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal ***Centro de Oceanografia, Faculdade de Ciencias, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal ****IMAR-Instituto do Mar, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa -Departamento de Ciencias e Engenharia do Ambiente. Quinta da Torre, 2829-516 Caparica, Portugal. *****BIOSCOPE Group, Physical-Chemistry Department, Faculty of Science, Campus Ourense, University of Vigo, 32004, Ourense, Spain. ******Unitat d´Enginyeria de Proteines i Proteomica, Institut de Biotecnologia i Biomedicina, Universitat Autonoma de 08193, Barcelona, Spain The increase in CO

A prática oceanográfica e a coleção iconográfica do rei dom Carlos I

After the Challenger expedition (1872-1878), other nations started to show interest in oceanographic research and organizing their own expeditions. As of 1885, Prince Albert I of Monaco conducted oceanographic campaigns with the collaboration of some of the best marine biologists and physical oceanographers of the day, inventing new techniques and instruments for the oceanographic work. Prince Albert’s scientific activity certainly helped kindle the interest of his friend, Dom Carlos I, king of Portugal, in the study of the oceans and marine life. Both shared the need to use photography to document their studies. This article analyzes the role of scientific photography in oceanography, especially in the expeditions organized by the Portuguese monarch.

Histological and biochemical effects of exposure to TiO 2 nanoparticles in livers of two freshwater fish species: Carassius auratus and Danio rerio

1REQUIMTE, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Centro de Quimica Fina e Biotecnologia, Universidade Nova de Lisboa, 2829-516 Caparica. 2Anatomia Patologica, Centro Hospitalar de Lisboa Central Hospital Curry Cabral, Rua da Beneficencia 8, 1069-166 Lisboa, Portugal, and Centro de Estudos do Ambiente e do Mar (CESAM/FCUL) – Faculdade de Ciencias da Universidade de Lisboa, Campo Grande, 1749-016, Lisboa, Portugal 3IMAR-Instituto do Mar, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa -Departamento de Ciencias e Engenharia do Ambiente. Quinta da Torre, 2829-516 Caparica, Portugal. 4LNEG, Estrada do Paco do Lumiar 22, 1649-038 Lisboa, Portugal *mesd@fct.unl.pt