RESUMO
The aim of this study was to improve the methodological procedure for the evaluation of sea urchin (Lytechinus variegatus) sperm sensitivity in MTT (3-(4,5-dimethylthiazol-2yl)-2,5 diphenyltetrazolium bromide) enzyme reduction assays with the formation of formazan (purple color) in the interior of viable cells. Assays were carried out with the reference toxicants sodium dodecyl sulfate (SDS), copper, zinc, cadmium and ammonium, using a sperm solution previously activated in sea water and a sperm solution prepared in sea water containing 400 µg L-1 verapamil, which enabled activation of the sperm to occur only when exposed to the toxicants. The assays performed with sperm in verapamil presented similar sensitivity to that shown in the fertilization tests with copper, zinc and SDS, while the assays carried out with the pre-activated sperm solution presented greater resistance to the action of the toxicants. It appears that the action of verapamil involves an intracellular effect on the distribution of Ca2+ ions and that the toxicants used prevent the metabolic reactivation of the sperm.
Assuntos
Colorimetria , Lytechinus/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Sais de Tetrazólio/química , Tiazóis/química , Testes de Toxicidade/métodos , Poluentes Químicos da Água/toxicidade , Compostos de Amônio/toxicidade , Animais , Sobrevivência Celular/efeitos dos fármacos , Formazans/química , Masculino , Metais Pesados/toxicidade , Dodecilsulfato de Sódio/toxicidadeRESUMO
Bacillus stratosphericus LAMA 585 was isolated from the Mid-Atlantic-Ridge seafloor (5,500-m depth). This bacterium presents the capacity for cellulase, xylanase, and lipase production when growing aerobically in marine-broth media. Genes involved in the tolerance of oligotrophic and extreme conditions and prospection of biotechnological products were annotated in the draft genome (3.7 Mb).
