title: Highly efficient conversion of lactate to pyruvate using whole cells of Acinetobacter sp.
abstract: 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.
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China.
authors.forename: Cui Qing
authors.initials: CQ
authors.lastname: Ma
authors.forename: Ping
authors.initials: P
authors.lastname: Xu
authors.forename: Yi Meng
authors.initials: YM
authors.lastname: Dou
authors.forename: Yin Bo
authors.initials: YB
authors.lastname: Qu
mesh_terms: 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
chemical_list: D019344:Lactic Acid; D019289:Pyruvic Acid; D006899:Mixed Function Oxygenases; C021497:lactate 2-monooxygenase