The effective sorption method for melanin isolation and purification from fermentation solutions of Bacillus thuringiensis serovar galleriae K1 has been elaborated, the principle process flowsheet is presented. The identification of obtained pigment with the samples of natural and synthetic melanin was done by IR-spectroscopy, and the intensity ratio of optical absorption at 650 and 500 nm allows to refer the isolated melanin to eumelanin class. By thermal treatment it was determined, that melanin's amorphous sediment is steady at up to 120 degrees C temperatures, at that the concentration of paramagnetic centers is changed from 0.053 x 10(18) spin/g (48 degrees C) to 0.25 x 10(18) spin/g (120 degrees C). The rising of the temperature of treatment up to 210 degrees C brings to substantial increase of the concentration of unpaired electrons, and at 280 degrees C its sharp growth is observed. At 350 degrees C growth stops, then sharp decrease is observed. The obtained results were confirmed by methods of IR spectroscopy and derivatographic analysis.