Highly efficient conversion of lactate to pyruvate using whole cells of Acinetobacter sp.
On an industrial scale, the production of pyruvate at a high concentration from the cheaper lactate substrate is a valuable process. To produce pyruvate from lactate by whole cells, various lactate-utilizing microorganisms were isolated from soil samples. Among them, strain WLIS, identified as Acinetobacter sp., was screened as a pyruvate producer. For the pyruvate preparation from lactate, the preparative conditions were optimized with whole cells of the strain. The cells cultivated in the medium containing 100 mM of l-lactate showed the highest biotransformation efficiency from lactate to pyruvate. The optimized dry-cell concentration, pH, and temperature of reaction were 6 g/L, pH 7.0-7.5, and 30 degrees C, respectively. The influences of ethylenediaminetetraacetic acid (EDTA) and aeration on a biotransformation reaction were carried out under the test conditions. Under the optimized reaction conditions, l-lactate at concentrations of 200 and 500 mM were almost totally stoichiometrically converted into pyruvate in 8 and 12 h, respectively. About 60% of 800 mM of l-lactate was transformed into pyruvate in 24 h. This reduced conversion rate is probably due to the high substrate inhibition in biotransformation.
Ma
Cui Qing
CQ
State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China.
Xu
Ping
P
Dou
Yi Meng
YM
Qu
Yin Bo
YB
D000150:Acinetobacter / Q000166:cytology / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D001711:Biotransformation; D018929:Cell Culture Techniques / Q000379:methods*; D002455:Cell Division / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D010865:Pilot Projects; D019289:Pyruvic Acid / Q000302:isolation & purification / Q000378:metabolism*; D013696:Temperature
D019344:Lactic Acid; D019289:Pyruvic Acid; D006899:Mixed Function Oxygenases; C021497:lactate 2-monooxygenase