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Glucose metabolism, enzymic analysis and product formation in chemostat culture of Hanseniaspora uvarum
Author(s) -
Venturin C.,
Boze H.,
Moulin G.,
Galzy P.
Publication year - 1995
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/yea.320110405
Subject(s) - chemostat , acetaldehyde , pyruvate decarboxylation , pyruvate decarboxylase , pyruvate dehydrogenase complex , biochemistry , pyruvate dehydrogenase kinase , alcohol dehydrogenase , pyruvate dehydrogenase phosphatase , biology , dehydrogenase , branched chain alpha keto acid dehydrogenase complex , ethanol metabolism , ethanol , cofactor , metabolism , enzyme , genetics , bacteria
The physiology of Hanseniaspora uvarum K 5 was studied in glucose‐limited chemostat cultures and upon glucose pulse. Up to a dilution rate of 0·28 h −1 , glucose was completely metabolized in biomass and CO 2 . Above this value, increase in the dilution rate was accompanied by sequential production of metabolites (glycerol, acetate and ethanol) and decrease in cell yield. Similar results were observed upon glucose pulse. From the enzyme activities (pyruvate dehydrogenase, pyruvate decarboxylase, NAD and NADP‐dependent acetaldehyde dehydrogenases, acetyl coenzyme A synthetase and alcohol dehydrogenase) and substrate affinities, the following conclusions were drawn with respect to product formation of cells: (1) pyruvate was preferentially metabolized via pyruvate dehydrogenase, when biomass and CO 2 were the only products formed; (2) acetaldehyde formed by pyruvate decarboxylase was preferentially oxidized in acetate by NADP‐dependent aldehyde dehydrogenase; acetate accumulation results from insufficient activity of acetyl‐CoA synthetase required for the complete oxidation of acetate; (3) acetaldehyde was oxidized in ethanol by alcohol dehydrogenase, in addition to acetate production.