Dissolved oxygen threshold for the repression of endo-polygalacturonase production by Kluyveromyces marxianus

A detailed study was conducted in terms of the influence of dissolved oxyge n (DO) and growth temperature related to the endo-polygalacturonase synthes is by the yeast Kluyveromyces marxianus CDBB-L-278. It was found that 3.3 m g of DO/1 was the threshold for the repression of enzyme production. Growth temperature had no effect on the synthesis of this enzyme, but had an indi rect effect due to changes in oxygen solubility. Growth rate was influenced by temperature; maintaining the dissolved oxygen constant at 3.3 mg of DO/ 1, the optimum growth temperature was 40 degrees C. Pectin in the culture m edium allowed higher endo-polygalacturonase production; even with 3.3 mg of DO/1, pectin de-repressed the enzyme production. (C) 1999 Elsevier Science Ltd. All rights reserved.