ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Summary The maltose utilization system of Candida utilis was affected by glucose through two different mechanisms: catabolite repression and inactivation. Maltose permease was under the control of both, whereas α-glucosidase was only repressed. In glucose-maltose continuous culture, both sugars were consumed simultaneously at glucose steady-state concentrations in the fermentor below 100 mg/l, corresponding to dilution rates lower than 0.4 h-1. At higher dilution rates, and consequently higher glucose concentrations, repression increased steeply, being complete when glucose concentration reached 170 mg/l. Glucose induced inactivation of maltose permease, in maltose-growing and resting cells, by decreasing V max, without changing maltose affinity for its transport system. The inactivation process apparently required the entrance of the inactivator into the cell and its subsequent phosphorylation because: 1) The specific inactivation rate showed a dependence on glucose similar to that of glucose transport and 2) only rapidly phosphorylated glucose analogues could mimic the inactivation effect.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00253901
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