Effect of Culture Conditions on the Production of d-Galactose Oxidase by Dactylium dendroides1

Abstract

Effect of culture conditions on the production of D-galactose oxidase by Dactylium dendroides. Appl. Microbiol. 13:686-693. 1965.-The effects on enzyme production of inoculum size and age, medium composition, and culture conditions were studied in shake flasks and in a pilot-plant fermentor. Using a medium consisting of glucose, yeast extract, and inorganic salts in deionized water, we found that the addition of Cu++ was essential for the formation of active enzyme. Cultures grown in the absence of added copper produced an inactive enzyme protein which could be activated by 103 M Cu+. Thiamine fulfilled all requirements for exogenous vitamins for growth and enzyme production. Glucose concentrations higher than 1% markedly suppressed enzyme formation. The mycelium inactivated the enzyme on prolonged incubation of the culture. Mycelial autolysates and sonic extracts were found to contain a thermostable and slowly dialyzable galactose oxidase-inactivating factor. The experiments suggest that this factor operates as a chelating agent which forms complexes with the copper of the enzyme. Copper ions (10I8 M) prevented enzyme inactivation and restored activity to samples previously inactivated by this factor.

Production, purification, and characterization of a novel galactose oxidase from Fusarium acuminatum

“…The results of this study demonstrate that the production of galactose oxidase by F. acuminatum is also dependent on these ions, but that the increase or decrease of Cu 2+ in the medium did not improve the enzyme yield. In agreement with our results, Markus et al (1965) demonstrated that neither mycelial growth nor enzyme activity was affected by the increase in CuSO 4 concentration up to 1 mM in the culture medium of F. graminearum.…”

“…The effect of the different carbon sources added to the liquid medium on the production of galactose oxidase by F. acuminatum was also investigated. In agreement with previous literature on F. graminearum and G. fujikuroi (Aisaka and Terada 1981, Markus et al 1965, Avigad et al 1962, glucose, galactose, and sucrose were found to be good carbon sources for galactose oxidase production by F. acuminatum and lactose was found to decrease enzyme production. Sorbose used in the culture medium as a carbon source for F. acuminatum was found to decrease enzyme production, however, sorbose has been used as the carbon source for enzyme production by F. graminearum because it doubles the amount of enzyme secreted (Tressel andKosman 1982, Markus et al 1965).…”

“…The lower enzyme production obtained with the largest inoculum size (6%) may be due to an excessive initial growth. Markus et al (1965) also found that slowly growing F. graminearum mycelia produced more enzyme than rapidly growing ones.…”

“…The production of galactose oxidase by F. graminearum requires the presence of Mg 2+ , Mn 2+ , and Cu 2+ (Tressel and Kosman 1982, Markus et al 1965, Avigad et al 1962. The results of this study demonstrate that the production of galactose oxidase by F. acuminatum is also dependent on these ions, but that the increase or decrease of Cu 2+ in the medium did not improve the enzyme yield.…”

“…The liquid medium used was the one described by Markus et al (1965), but modified to contain 100 mM of phosphate buffer. This medium was prepared from three solutions: solution A: 15.14 mM (NH 4 ) 2 SO 4 , 12.5 mM NH 4 NO 3 , 0.1% yeast extract, 42 mM KH 2 PO 4 , 58 mM Na 2 HPO 4 , with pH corrected to 7.0 with HCl or NaOH; solution B: 1.62 mM MgSO 4 ⋅ 7 H 2 O, 12 µM MnSO 4 ⋅ H 2 O, 10 µM CuSO 4 ⋅ 5 H 2 O; and solution C: 1% glucose.…”