Growth characterization of Propionibacterium and propionic acid production capabilities at different temperatures and pH levels.

Abstract

Bacteria from the Propionibacterium genus were cocktailed to investigate growth and production of propionic acid at different temperatures and pH levels. A gas chromatograph with a flame ionization detector was also used for instrumental analysis. The Propionibacterium cocktails did not produce propionic acid at 10 and 20°C for 10days, but produced propionic acid at concentrations of 3265.32, 3670.76, and 1926.04μg/mL at 25, 30, and 40°C for 18days, respectively. In pH tests, the cocktails did not produce propionic acid at pH 3 and 9 for 14 and 7days, respectively. However, they produced propionic acid at concentrations of 2596.66, 2952.66, 3321.35, and 3586.95μg/mL at pH 4, 5, 6, and 7 for 18days, respectively. Growth characteristics of Propionibacterium cocktails by temperature and pH were set so that they reached the extinction stage after four days in the logarithmic phase.