Estimation of the true growth yield and maintenance coefficient for yoghurt cultures

Abstract

Point and 95% confidence interval estimates of the true growth yield and maintenance coefficient are reported for four pure cultures andtwo mixed cultures of Lactobacillus bulgaricus and Streptococcus thermophilus grown anaerobically on 3% nonfat dry milk using batch followed by fed batch culture. An improved method of data analysis, which includes separate analysis of the exponential growth region and a new method of selecting smoothing spline functions, is utilized. The parameter estimation results are compared with the theoretical maximum yields for one and two moles of ATP produced per mole of glucose and to the growth yield estimated from the exponential growth region analysis.