Cell Bound α-Amylase inAspergillus oryzae

It has been found that exocellular α-amylase could be fixed to mycelia of Aspergillus oryzae at an acidic pH region and fixed α-amylase was released reversely at an alkaline pH region. The fixation has more remarkably been observed in mycelia obtained from a phosphate deficient medium where endocellular accumulation of a-amylase occurs more easily than in an ordinary mycelia which secrete a large amount of α-amylase into medium. Bound form of α-amylase was more resistant to low pH and less active than the free form. The results appear to support the previous suggestion that a large quantity of endocellular α-amylase might be located on mycelial surface of the mold.