ABSTRACT
Screening of producers of alpha-N-acetylgalactosaminidase among 854 strains of micromycetes, 171 yeast and 357 bacterial cultures has been carried out. A capacity to synthesize the enzyme was revealed in 11% of cultures. Representatives of Aspergillus genus (activity--0.11-0.142 un./ml) were most active in producing the enzyme. It has been established that glucosidases spectrum in the culture liquid of 18 most active strains was characterized by complete homogeneity and by the presence of a rather high level (0.5-0.9 un./ml) of alpha-galactosidase activity. Complex preparations of alpha-N-acetylgalactosaminidase and alpha-galactosidase have been obtained from the culture liquid of producers by fractionation by ammonium sulphate (30 and 90% saturation); their pH- and thermo-optimum, pH- and thermal stability have been studied. It was shown possibility to induce alpha-N-acetylgalactosaminidase synthesis by a number of carbohydrates (galactose, glucose, galactosamine, and glucosamine), complex-forming substances (guanidine HCl), nitroaminoguanidin and guanidine carbonate and bovine blood. As a result the strain of Aspergillus niger 185 III was chosen which activity level could be increased more than 3 times (activity--0.6 un./ml as compared to initial one).
