title: [Synthesis of melanin pigments by Antarctic black yeast].
abstract: Five strains of the black yeast similar to Exophiala nigra (Nadsoniela nigra), which we have isolated from the Antarctic biotopes, are studied. At cultivation in a periodic operation the maximum level of absolutely dry biomass in five tested strains constituted 3.2-7.8 g/l of medium, melanin pigment yield being 6-9% of absolutely dry mass of cells. Two highly productive strains have been selected. Pigments of the studied black yeast are water-insoluble, however dissolve in alkali and concentrated acids. The maximum absorption of the yeast pigments was in the range of 220 nm. The above-stated properties of pigments of the investigated yeast correspond to the description of melanin fractions of Nadsoniela nigra and some microscopic mushrooms. The water-soluble melanin-pigments have been obtained after the dialysis of alkaline solution of the pigment. UV-spectra and visible absorption spectra of water solution of melanin-pigments are almost identical to those of initial alkaline solutions. It is shown that the studied yeast are resistant to high concentrations of toxic metals (Hg2+, Cu2+, Co2+, Cr(VI) and Ni2+), and introduction of Co2+ into the cultivation medium leads to the increase of pigments synthesis.
authors.forename: A B
authors.initials: AB
authors.lastname: Tashirev
authors.forename: V A
authors.initials: VA
authors.lastname: Romanovskaia
authors.forename: P V
authors.initials: PV
authors.lastname: Rokitko
authors.forename: N A
authors.initials: NA
authors.lastname: Matveeva
authors.forename: S O
authors.initials: SO
authors.lastname: Shilin
authors.forename: A A
authors.initials: AA
authors.lastname: Tashireva
mesh_terms: D000864:Antarctic Regions; D001688:Biological Products / Q000378:metabolism*; D002413:Cations, Divalent; D002857:Chromium / Q000494:pharmacology; D003035:Cobalt / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology; D003470:Culture Media; D005093:Exophiala / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D008543:Melanins / Q000096:biosynthesis*; D008628:Mercury / Q000494:pharmacology; D009532:Nickel / Q000494:pharmacology; D012988:Soil Microbiology; D012995:Solubility; D012997:Solvents; D013053:Spectrophotometry
chemical_list: D001688:Biological Products; D002413:Cations, Divalent; D003470:Culture Media; D008543:Melanins; D012997:Solvents; D002857:Chromium; D003035:Cobalt; D003300:Copper; D009532:Nickel; D008628:Mercury