Lysobacter oligotrophicus strain 107-E2(T) isolated from Antarctica produces dark-brown colored water-soluble pigment, in addition to hydrolases and lytic enzymes. The production of pigment is a common characteristic among members of the genus Lysobacter, but the identity of the pigments has been unknown. In this study, we identified the pigment from L oligotrophicus as melanin pigment (Lo-melanin) by chemical and spectroscopic analyses. Although melanin is generally insoluble in both aqueous and organic solvents, the results in this study revealed that Lo-melanin shows water-solubility by means of the added polysaccharide chain. Lo-melanin production of L. oligotrophicus was increased by ultraviolet (UV) exposure, and survival rate of Escherichia coli under UV-irradiated condition was increased by the addition of Lo-melanin to the medium. (C) 2014, The Society for Biotechnology, Japan. All rights reserved.