Abstract
Marine algae have various antibacterial molecules to protect them from pathogens. To identify new antibacterial molecules, we examined five red algae (Scinaia japonica, Galaxaura elegans, Callophyllis japonica, Gelidium elegans, Ptilopbora subcostata) to screen antibacterial molecules. These red algae were homogenized with distilled water, and then incubated with Bacillus subtilis spores in agar well diffusion assay . We found that the extract of Ptilopbora subcostata inhibited growth of the bacteria. We partially purified the antibacterial molecule with anion-exchange column chromatography. The partially purified fraction was applied to SDS-PAGE . Two major bands with molecular masses of 40kDa and 29kDa were detected. N-terminal sequence of 29kDa shows high similarity to hexose oxidase from Chondrus crispus. The antibacterial activity of the fraction did not inhibit the growth of bacteria in a medium containing catalase or a medium without glucose. These data indicate that P. subcostata hexose oxidase in the antibacterial molecule.
