Tashirev A B, Romanovskaia V A, Rokitko P V, Matveeva N A, Shilin S O, Tashireva A A
Mikrobiol Z. 2012 Sep-Oct;74(5):2-8.
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.
我们对从南极生物群落中分离出的五株类似于黑色外瓶霉（纳氏瓶霉）的黑色酵母菌株进行了研究。在分批培养过程中，五个受试菌株的绝对干生物量最高水平为每升培养基3.2 - 7.8克，黑色素产量为细胞绝对干重的6 - 9%。已筛选出两株高产菌株。所研究的黑色酵母色素不溶于水，但可溶于碱和浓酸。酵母色素的最大吸收波长在220纳米范围内。所研究酵母色素的上述特性与纳氏瓶霉和一些显微蘑菇的黑色素组分描述相符。色素的碱性溶液经透析后得到了水溶性黑色素色素。黑色素色素水溶液的紫外光谱和可见吸收光谱与初始碱性溶液几乎相同。结果表明，所研究的酵母对高浓度有毒金属（Hg2 +、Cu2 +、Co2 +、Cr(VI)和Ni2 +）具有抗性，并且向培养基中添加Co2 +会导致色素合成增加。
