title: High-Efficiency Conversion of Pyruvate to Acetoin by Lactobacillus plantarum during pH-Controlled and Fed-Batch Fermentations.
abstract: The influence of pH on the type and concentration of metabolites produced from pyruvate by Lactobacillus plantarum ATCC 8014 was examined in pH-controlled fermentors at pH values of 4.5 to 6.5. Specific growth rates, cell dry weights, and diacetyl concentrations were highest at pH 5.5, with values of 0.78 h, 190 mg/liter, and 1.2 mM, respectively. While the conversion efficiency (millimoles of acetoin formed per millimoles of pyruvate utilized) was highest (94.6%) at pH 4.5, acetoin levels were similar (20 mM) between pH 4.5 and 5.5. Feeding stationary-phase cells exogenous pyruvate increased acetoin levels to 78 mM.
authors.affiliation: Department of Food Science, New Jersey Agricultural Experiment Station, Cook College, Rutgers-The State University of New Jersey, New Brunswick, New Jersey 08903.
authors.forename: T J
authors.initials: TJ
authors.lastname: Montville
authors.forename: A H
authors.initials: AH
authors.lastname: Hsu
authors.forename: M E
authors.initials: ME
authors.lastname: Meyer