Process for preparing glucoamylase

Claim 1

In a process for the production of glucoamylase comprising, cultivating a culture of a glucoamylase-producing microorganism in a pre-sterilized nutrient medium under aeration in a plurality of development stages and thereafter inoculating, in a final development stage, the last culture development stage (seed stage) of glucoamylase-producing microorganisms in a pre-sterilized fermentation medium comprising a carbon source in the form of carbohydrates and a nitrogen source, wherein the carbon source comprises enzymatically liquified ground corn, and fermenting the innoculated pre-sterilized fermentation medium to thereby obtain the glucoamylase enzyme, the improvement comprising: preparing the sterilized fermentation medium by the steps comprising: (1) forming a fermentation medium by admixing ground corn as a primary carbon source, a primary nitrogen source and water at a temperature ranging from about 20° C. to about 60° C.; (2) heating the medium in step (1) by the action of steam to a temperature in the range from about 55° C. to about 80° C. and at a pH in the range from about 4.5 to about 7.5 in the presence of a bacterial alpha-amylase preparation derived from a Bacillus licheniformis microorganism, said bacterial alpha-amylase enzyme preparation being added to the medium before or during the steam heating of the medium for a time sufficient to substantially liquify all the ground corn (3) further heating the medium by the action of steam at a temperature of at least 100° C. and holding the medium at this temperature to sterilize the medium; and (4) cooling the medium to thereby obtain a sterilized fermentation medium containing enzymatically liquified ground corn having a solids content greater than about 16% and up to about 25% by weight dry substance basis which is inoculated with the development stage (seed stage) of glucoamylase-producing microorganism to produce glucoamylase by fermentation in said medium.