Open AccessFormation of diacetyl by cell‐free extracts of Leuconostoc lactis
Author(s) -
Jordan Kieran N.,
O'donoghue Margie,
Condon Seamus,
Cogan Timothy M.
Publication year - 1996
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1996.tb08495.x
Subject(s) - acetoin , diacetyl , chemistry , thiamine pyrophosphate , biochemistry , anaerobic exercise , lactococcus lactis , leuconostoc , food science , bacteria , cofactor , lactic acid , fermentation , biology , lactobacillus , enzyme , physiology , genetics
Diacetyl formation was linear with time and with protein concentration when a cell‐free extract of Leuconostoc lactis NCW1 was added to a buffer system containing pyruvate, thiamine pyrophosphate and MgS 4 (final concentrations 60 mM, 0.11 mM and 0.22 mM, respectively). No diacetyl was detected in the absence of pyruvate or cell‐free extract and no increase in diacetyl formation was detected on the addition of acetyl‐CoA. When 2‐acetolactate (1.6 mM) was the substrate, autodecarboxylation to diacetyl and acetoin occurred under aerobic and anaerobic conditions. When cell‐free extract was added, decarboxylation of 2‐acetolactate to acetoin and diacetyl increased 4–6‐fold, under aerobic and anaerobic conditions. When the cell‐free extract was boiled, diacetyl formation from 2‐acetolactate was reduced to the level of autodecarboxylation. The results suggest that diacetyl is formed enzymatically in the presence and absence of oxygen, as well as spontaneously, from 2‐acetolactate.