Beschreibung:
<jats:title>Abstract</jats:title><jats:p>The problem of resistance and infectious pathogenicity of bacteria to humans is new at now. The search for alternative new drug compounds from seaweed bioactive content as one of the new antibacterial sources. The purpose of this research is to utilize<jats:italic>Gracilaria sp</jats:italic>. on the antibacterial effectiveness of<jats:italic>Escerichia coli</jats:italic>,<jats:italic>Clostridium perfringens</jats:italic>and<jats:italic>Stapylococcus aureus</jats:italic>The method used in an experimental laboratory. Extraction was done by maceration with n-hexane, ethyl acetate and ethanol. Test antibacterial activity by agar diffusion method. Phytochemical screening based on discoloration. Analysis of bacterial cell leakage based on spectrophotometer results. Yields of 8.08% (ethanol), 5.47% (ethyl acetate) and 1.10% (hexane). Phytochemical screening results contain 6 secondary metabolite compounds in the ethanol and hexane treatment and 7 compounds in the ethyl acetate treatment. The best activity test results on ethyl acetate solvent with inhibition zone of 33.54 mm (<jats:italic>Esherichia coli</jats:italic>), 24.12 mm (<jats:italic>Clostridium perfringens</jats:italic>) and 29.14 mm (<jats:italic>Stapylococcus aureus</jats:italic>). MIC value at 0.51%. The absorbance obtained was 0.178 to 1.898 at a wavelength of 260 nm and 0.149 to 1,328 at a wavelength of 280 nm.</jats:p>