Highly efficient production of Aspergillus niger amylase cocktail by solid-state fermentation using triticale grains as a well-balanced substrate

Abstract

Triticale (Triticosecale, Wittmak) an important industrial crop, with high grain yield, containing high amounts of starch, proteins and also major and minor mineral elements, is not sufficiently utilized yet. The simultaneous production of ?-amylase and glucoamylase isoforms by Aspergillus niger on triticale grains, without any nutritive supplements, has been developed, optimized and scaled up 10 fold for the first time. The specific combination of examined effects led to the production of a novel glucoamylase isoform. Reduction of particle size, increase of oxygen availability and substrate height lead to increase of amylases production of 30%. Reduction of relative humidity from 65% to 30% increased glucoamylase production 2 times and ?-amylase production for 30%. Peak production of ?-amylase (158 U/g) and glucoamylase (170 U/g) were obtained in erlenmayers and in scaled-up trays. The obtained A. niger amylase cocktail was more efficient in raw starch hydrolysis from wheat flour, 29% more efficient in glucose formation and 10% more efficient in total reducing sugar formation, than commercially available amylase cocktail SAN Super 240L widely used in industry.