Extratos lipídicos de seis macroalgas (Rhodophyta e Chlorophyta) coletadas na costa do Estado do Ceará foram avaliadas para atividade antibacteriana pelo método de difusão em disco. Os extratos de Amansia multifida (obtidos a partir dos solventes orgânicos hexana, clorofórmio e etanol) demonstraram os melhores resultados contra as espécies entéricas Gram negativas de Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, S. cholerae-suis, Serratia marcescens, Vibrio cholerae e bactérias Gram positivas Bacillus subtilis e Staphylococcus aureus.

Hexane, chloroform and ethanol extracts of six marine macroalgae (Rhodophyta and Chlorophyta) from North Ceará coast (Northeast Brazil) were evaluated for antibacterial activity by the single disk method. Best results were shown by the hexane extracts of Amansia multifida against enteric Gram-negative strains such as Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, S. cholerae-suis, Serratia marcescens, Vibrio cholerae and the Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus.