c action. Presently at the industrial receipt of foods of hydrolysis of starch - decstrose, glucose and fructose syrups, on the stage of saccharification mainly use glucoamylases of producers, related to the genus Aspergilllus: Asp. niger. Asp. awamori, Asp. oryzae, optimal conditions of action of which рН 5.0 and temperature 55 o С.
Aspergillus are typical obligate aerobs, therefore they can develop only on the surface of solid or liquid medium or in a liquid, aerated enough medium. Optimal temperature for majority of Aspergillus 25-30 В° С, for some it is to 35 В° С. The majority of molds at surface cultivation can undergo short-term increase of temperatures to 40 В° C and even 45 В° C without the noticeable loss of enzymes activity. Optimal humidity of medium for them is about 65%. p align="justify"> The recombinant and mutant strains of glucoamylase producers molds Aspergillus niger are known. Such strains are described: Asp. niger, synthesizing 150 unit/ml of glucoamylase; Asp. niger N 402, got on the basis of natural strain, contains 20 copies of gene of glucoamylase; Asp. niger B0-1. Asp. oryzae is a mutant that synthesizes both glucoamylase and amylase. The use of recombinant strains is related to the necessity of realization of permanent researches on maintenance of strains in the stable and active state, by creation of the special conditions of cultivations which not always are accessible at the industrial conduct of process.of species Asp. awamori for the saccharification of starch-containing raw material at the industrial receipt of dextroses, glucose and fructose syrups, ethanol are known and widely used.enough in regard to the synthesis of glucoamylase from the known mold Asp. awamori is Asp. awamori 466, synthesizing 183 units/ml of enzyme at growth on medium with a corn-flour at the use of saccharification by malt milk and malt mash with diammonium phosphate during184 h of growth. Mycelium is strongly branched, with swelling, septate; a diameter of hyphae is 10-12 ? m, the form of conidium is rounded cylindrical or irregular; diameter of conidium 4.4-6.4 ? m, color - from olive-yellow to darkly-olive. [ Appendix. A1] descriptions: colonies on the Dox s agar of with a yeast extract, at 25 o С, have a diameter of a 70-71 mm/7days, radially grooved, surface velvety, edge thin, a conidial area is an umber; an exudate absent, back is dim-yellow.descriptions: conidial heads are spherical, disintegrating on separate columns, conidiophores weakly tinctured in terminal part, apical expansions are spherical 20-45 ? m in a diameter , st...
