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The pollution of aquatic bodies by pharmaceutical compounds is an emerging environmental problem, with little explored consequences. Oxytetracycline (OTC) is an antibiotic used for treatment of infections caused by a variety of microorganisms and it is widely employed in medicine, livestock husbandry and aquaculture. This pharmaceutical compound may cause deleterious effects on non-target aquatic organisms as microalgae. The objective of this study was to evaluate the effects of OTC on growth, pigment content and morpho-physiology of the microalga Isochrysis galbana Parke. The results highlighted that OTC exposure inhibited the growth of I. galbana in cultures treated with OTC 5.0 and 10.0 mg/L after 3 days and in cultures treated with OTC 5.0, 7.5 and 10.0 mg/L after 5 days. Effects of OTC on cells ultrastructure and physiology consisted in large cytoplasmic lipid inclusions and in a decrease of photosynthetic pigments amount. Image 1 • OTC affects growth, pigment content and cell ultrastructure of Isochrysis galbana. • An inhibitory effect of OTC on I. galbana was more evident in the stationary phase. • A decrease in pigment content was observed in cultures treated with OTC 10.0 mg/L. • OTC caused lipid inclusions formation and chloroplast alterations in I. galbana. This work highlights for the first time the effects of oxytetracycline on the morpho-physiology of the microalga Isochrysis galbana Parke. [ABSTRACT FROM AUTHOR]

Abstract In this work the antifouling properties of different Plasma Electrolytic Oxidation (PEO) coatings produced on samples of 7075 aluminum alloy were studied and compared with those of samples treated with more commercial treatments, such as traditional anodizing and painting, and untreated ones. After the treatments, the different samples were characterized through scanning electron microscope (SEM) observations. The antifouling tests were carried out immersing the different coated samples in the Piave river for a month, collecting one sample series every week. After the immersion test, to evaluate the colonization by microalgae, the samples were investigated through stereomicroscope, inverted light microscope, and SEM. Results showed that the addition of silver/copper particles in the electrolyte does not modify the PEO process, obtaining thick and adherent coatings that contain particles both inside and outside of the pores. As regards the antifouling properties, surface PEO treated with copper particles exhibited a good effect inhibiting the colonization by microalgae. Highlights • Plasma Electrolytic Oxidation (PEO) coating with copper particles exhibited good effect inhibiting colonization by microalgae. • All the treated samples are characterized by higher corrosion resistance. • In all tested samples the developed microfouling communities were dominated by benthic diatoms. • Combination of copper-containing PEO coating with varnish gives to the sample good corrosion and fouling resistance. [ABSTRACT FROM AUTHOR]

The pollution of aquatic bodies by drugs is an emerging environmental problem, because of their extensive use in animal and human context. Ibuprofen, 2-[4-(2-methylpropyl)phenyl]propanoic acid, is the non-steroidal anti-inflammatory drug mainly present both in wastewater and in rivers and lakes in Europe. Since in literature there is little information about the effects of ibuprofen on microalgae, in this paper we presented the results on the effects of this molecule at different concentrations (62.5 μg L −1 , 250 μg L −1 and 1000 μg L −1 ) on cultures of the freshwater microalga Scenedesmus rubescens (P.J.L. Dangeard) E. Kesslet et al. Ibuprofen effects on the alga were assayed at first through analyses of the growth curve. Moreover, analyses of cell morphology, ultrastructure, and photosynthetic pigments were additionally performed. The first negative effect of the drug was on the microalga growth, suggesting a drug action dose-dependent mechanism type, more evident at the concentration of 1000 μg L −1 ibuprofen and in the last phase of the growth curve. In support of this, following ibuprofen exposure, the cells exhibited morphological and ultrastructural alterations, mainly consisting in large cytoplasmic inclusions, probably of lipids and/or carotenoids. The decrease of chlorophyll amounts and, on the contrary, the increase of carotenoids were correlated with a stressful condition induced by drug. [ABSTRACT FROM AUTHOR]