USE OF GREEN ALGAE Oocystis sp LIKE A BIOLOGICAL MODEL FOR TOXICOLOGICAL EVALUATIONS OF BDE-209

DARUICH, G.J; GONZALEZ, P; ALMEIDA, C; PÉREZ-IGLESIAS JM

Congreso; XXXVII Reunión Científica Anual, Sociedad de Biología de Cuyo.; 2019

Microalgae are photoautotrophic oxygen evolving microorganisms which includes (Chlorophyceae, Cyanophyceae and Bacillariophyceae). They are morphologically diverse and of extensive distribution. Microalgae reflect a wide range of physiological properties and are more tolerant to environmental stress. Therefore, they have been widely used as model species to evaluate different environmental stressors in ecotoxicological tests. The microalgae Oocystis sp is one of the numerous planktonic green algae, usually of reservoir waters. It has characteristics of a model species: rapid growth and it is easy to handle in laboratory conditions. Our goal is to propose to Oocystis sp as a model species for ecotoxicological tests. The samples of the microalgae were collected with a phytoplankton net from temporary puddles in the town of El Volcán, San Luis province. In the laboratory, the organisms were kept in BBM culture medium (Bold´s Basal Medium). The initial biomass (6 106 cells / mL) was exposed to contaminants such as polybrominated biphenyls (BDE-209) of known toxicity for 96 h. Cell count examination was performed using haemocytometer (Neubauer) under Optic Microscope (400X), chlorophyll stress index and oxidative stress enzymes (ROS) by spectrometry. Oocystis sp showed sensitivity with a 50% growth inhibition with respect to the control from 100 µg / L for BDE-209. Catalase values were increased with values greater than 100 µg/L of BDE-209; while TBARS showed differences only in algae exposed to BDE-209 at 100 µg/L. Chlorophyll showed signs of stress and senescence from 100 µg/L BDE-209 (value 0.03 mg/g). Oocystis sp showed toxicity response evaluated, which provides relevant information about sensitivity, and can be used as a model in environmental risk studies to BDE-209.