A dicarboxylic acid compound obtainable by oxidative degradation of pradimicin antibiotics, which are antibiotics consisting of the benzonaphthacene skeleton, a D-amino acid side chain and a sugar chain, for the second saccharide residue of the sugar chain, and use thereof utilizing a specific microorganism binding property thereof are provided. The dicarboxylic acid compound has significantly improved water-solubility compared with the raw material antibiotics, whist maintaining the specific microorganism binding property.