Growth and Lactic Acid Production of Probiotic Lactobacillus acidophilus D59 in Skim Milk Medium Containing Oligosaccharides

The objective of this study was to investigate the growth and lactic acid production of probiotic Lactobacillus acidophilus D59 in skim milk medium containing oligosaccharides. The growth and acid production of L. acidophilus D59 were significantly higher in skim milk than in brain heart infusion broth. When fructooligosaccharide (FOS) was added to skim milk medium than galactooligosaccharide, the strain produced a higher amount of lactic acid. The maximum viable cell number and acid production of D59 strain were observed in skim milk medium supplemented with 5% FOS. In addition, the D59 strain produced the highest amount of lactic acid when cultured in skim milk supplemented with FOS adjusted to pH 6.0 for 18 hr at 37℃. The final bacterial counts and lactic acid content of D59 strain cultured in skim milk medium supplemented with FOS were proportional to the initial number. The content of lactic acid produced by this strain was significantly higher when cultured under anaerobic conditions than anaerobic conditions.