Screening of Nitrogen Sources in the Medium for <i>Streptococcus thermophilus</i> Using Plackett–Burman Design

Abstract

This study demonstrates that the type of nitrogen sources has an important influence on the growth of Streptococcus thermophilus.at the same time ,viable counts was studied by in the medium containing various nitrogen sources (peptone, yeast extract, meat extract, tryptone，soya peptone and casein hydrolysate). The results indicated that soya peptone was the most efficient nitrogen source and and the influence of different concentrations of soya peptone on growth was determined. The results indicated that viable bacteria were stimulated by the high soya peptone concentration (30g/L).