SUGAR ABSORPTION BY CHAETOMIUM GLOBOSUM

Abstract

The absorption of the sugars, glucose and fructose, by Chaetomium globosum does not involve an accumulation against an internal concentration but is associated with immediate assimilation. The process is sensitive to the presence of inhibitors, anaerobiosis, and to the concentration supplied. The relationship to concentration is hyperbolic and the half maximum rates occur at about 6–8 × 10‐3 M for fructose and 9 × 10‐5 M for glucose. Glucose and fructose compete for the uptake mechanism so that in mixed solutions when the glucose concentration is at about 13% of that of fructose the uptake of the latter is abolished. The uptake of carbohydrate from sucrose solutions is mainly an uptake of the hexose moeities released from sucrose. The amount of sucrose absorbed intact is very small. Sucrose is split by an enzyme system which appears to be located at or near the hyphal surface. It is relatively resistant to temperature and metabolic inhibitors and appears to be stimulated by alkali metal ions in solution. Copyright © 1962, Wiley Blackwell. All rights reserved