The effect of microplastics pollution in microalgal biomass production: a biochemical study

Microplastics (MPs) are widely spread throughout aquatic systems and water bodies. Given that water quality is one of the most important parameters in the microalgal-based industry, it is critical to assess the biochemical impact of short- and long-term exposure to MPs pollution. Here, the microalga Phaeodactylum tricornutum was exposed to water contaminated with 0.5 and 50 mg L-1 of polystyrene (PS) and/or polymethyl methacrylate (PMMA). Results show that the microalgal cultures exposed to lower concentrations of PS displayed a growth enhancement of up to 73% in the first stage (days 3-9) of the exponential growth phase. Surprisingly, and despite the fact that long-term exposure to MPs contamination did not impair microalgal growth, a steep decrease in biomass production (of up to 82%) was observed. The production of photosynthetic pigments was shown to be pH-correlated during the full growth cycle, but cell density-independent in later stages of culturing. The extracellular carbohydrates production exhibited a major decrease during long-term exposure. Still, the production of extracellular proteins was not affected by the presence of MPs. This pilot laboratory-scale study shows that the microalgal exposure to water contaminated with MPs disturbs its biochemical equilibrium in a time-dependent manner, decreasing biomass production. Thus, microalgal industry-related consequences derived from the use of MPs-contaminated water are a plausible possibility.info:eu-repo/semantics/publishedVersio

Análise da permeabilidade das luvas de látex para procedimento mais utilizadas por alunos da Faculdade de Odontologia da Universidade Federal da Bahia

The objective of this paper is to analyze the permeability of latex gloves, used by dentistry students of Federal University of Bahia. Forty gloves from two different brands which were filled with water plus violet gentian were observed. After two hours they presented superficial damp.Este trabalho teve como objetivo analisar a permeabilidade das luvas de látex para procedimento mais usadas por alunos da Faculdade de Odontologia da Universidade Federal da Bahia. Foram observadas quarenta luvas de duas marcas distintas, as quais, que após duas horas infladas com água corada com violeta de genciana, apresentaram umidade superficial