Abstract
The authors previously suggested that a possible mechanism for the “Konjac” mannan metabolism by A. mannanolyticus may be related to glyoxylate pathway. However, later it was found that isocitritase was significantly formed in the cells grown on citrate medium, while no enzyme activity was measured in the cells grown on glucose medium. It was presumed from this that isocitritase may be adaptively formed by A. mannanolyticus grown on citrate. medium.
In the present paper, each enzyme activity concerning the TCA cycle in A. mannanolyticus was measured.
Most of the enzymes relating to the TCA cycle have been demonstrated to be presented constitutively in cell free extracts of A. mannanolyticus grown on citrate medium from the experimental data.
In conclusion, the authors correct the previous hypothesis for the “Konjac” mannan metabolism and propose as follows; “Konjac” mannan in human diet is decomposed to glucose and mannose by A. mannanolyticus in intestine, and subsequently a part of these sugars may be finally metabolized via TCA cycle by A. mannanolyticus in our gastrointestine.
