ИСТИНА

Microscopic fungi of extreme habitats represent the promising organisms for producers of enzymes with new properties. The purpose was the evaluation of spectrum of extracellular proteases of alcaliphilic and alkalotolerant fungi Sodiomyces alkalinus, S. magadi, Chordomyces antarcticum, Acrostalagmus luteoalbus, Verticillium zaregamsianum, Gibellulopsis nigrescens. The spectrum of different classes of peptidases have been identified with azocasein and specific synthetic para-nitroanilide substrates (endopeptidase -GlpAALpNA, GlpFpNA, BzRpNA, GlpFApNA и экзопептидаз - LpNA, FpNA, ЕpNA, APpNA, GPpNA, RPpNA). The measurements were carried out in the culture fluid at pH 9.5. Two types of aminopeptidase activity were detected between the strains. The greatest activity was shown on the substrate with leucine residue - LpNA. The activity was significantly lower or absent on the substrate L-Phenylalanine-4-nitroanilide. The strains did not hydrolyze L-Glutamic acid 1-(4-nitroanilide) or their activity were low. Majority of strains have demonstrated high metalloprotease activity. The strains with trypsin and chymotrypsin activities of serine proteases were not detected. At the same time, half of strains had active subtilisin serine proteases. Strains with high protease activity at pH 6-10, 30-50 °C, high concentrations of NaCl (up to 30%) and the content of Triton X-100 - 8% and Ariel detergent in the culture fluid were selected.