Melanins are widely used in medicine, pharmacology, cosmetics and other fields. Although several technologies for the purification of water-insoluble dioxyphenylalanine (DOPA) melanins have been described, a source of water-soluble melanin is highly desirable. Here we describe an effective procedure for the isolation and purification of water-soluble melanin using the culture medium of Bacillus thuringiensis subsp. galleriae strain K1. Water-soluble melanin from this organism has an isoelectric point (pI=3.0-3.2) and was purified optimally by adsorbtion using the IA-1r resin and elution as a concentrated solution. The purified melanin obtained exhibited a similar infra-red absorbtion spectrum to synthetic melanin and contained quinolic and phenolic structures and an amino acid content of around 20% after acid hydrolysis. The molecular weight of the purified melanin determined by SDS-PAGE was 4 kDa and the electromagnetic spin resonance spectrum of the purified microbial melanin was a slightly asymmetric singlet without hyperfine structure with about 7 Gauss width of the line between points of the maximum incline and g=2.006. The concentration of paramagnetic centers in melanin is 0.21x10(18) spin/g. The results obtained provide a rapid, simple and inexpensive method for the large scale purification of water soluble melanin that may have widespread applications.

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XANES and EPR spectra data are presented which prove the existence of holes with 3d9L configuration in YBa 2 Cu 3 O 7 − δ at 293 K. With a growth of concentration of these holes, the absorption intensity in XANES spectra near the absorption of the formally trivalent copper at T < T c grows with the increase of T c . When this absorption appears in XANES spectra at T < T c , disappearance of EPR signal is observed under the same conditions. Such absorption is also observed in the bismuth ceramics at T < T c . The data obtained prove that pairing holes make a contribution to this absorption.