ISSN:
0749-503X
Schlagwort(e):
Pyruvate decarboxylase
;
yeast
;
Candida utilis
;
Kluyver effect
;
glycosidase
;
β-glucosidase
;
anaerobic sugar fermentation
;
aerobiosis
;
anaerobiosis
;
activation
;
deactivation
;
catabolite repression
;
enzyme induction
;
Life and Medical Sciences
;
Genetics
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Biologie
Notizen:
The glucose-fermenting yeast, Candida utilis cannot use the β-D-glucoside, cellobiose, anaerobically, although it is able to do so aerobically. β-Glucoside transport and hydrolysis and pyruvate decarboxylase activities of this yeast were measured aerobically and anaerobically. β-Glucoside transport was five-fold faster aerobically than anaerobically, but there was no corresponding difference in β-glucosidase activity. Pyruvate decarboxylase activity varied greatly, being synthesized de novo in response to the presence of D-glucose and anaerobic conditions and about 50% deactivated on the removal of D-glucose or the addition of air. Activation and deactivation were rapidly reversible. Failure to utilize cellobiose anaerobically, in particular, and the Kluyver effect, in general, probably depends on much reduced glycolytic flux, associated under anaerobic conditions, with (i) lower transport rate, (ii) low substrate affinity of the relevant glycosidase and (iii) deactivation of pyruvate decarboxylase. So, in addition to the complex effects of oxygen, anaerobiosis and specific sugars on induction, repression and derepression, there are fine controls on pyruvate decarboxylase activity, leading to fast activation or deactivation of the enzyme.
Zusätzliches Material:
6 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/yea.320070507
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