Characterization of a galactokinase-positive recombinant strain of Streptococcus thermophilus.

ABSTRACT: The lactic acid bacterium Streptococcus thermophilus is widely used by the dairy industry for its ability to transform lactose, the primary sugar found in milk, into lactic acid. Unlike the phylogenetically related species Streptococcus salivarius, S. thermophilus is unable to metabolize and grow on galactose and thus releases substantial amounts of this hexose into the external medium during growth on lactose. This metabolic property may result from the inability of S. thermophilus to synthesize galactokinase, an enzyme of the Leloir pathway that phosphorylates intracellular galactose to generate galactose-1-phosphate. In this work, we report the complementation of Gal(-) strain S. thermophilus SMQ-301 with S. salivarius galK, the gene that codes for galactokinase, and the characterizatio

SUBMITTER: Vaillancourt K 

PROVIDER: S-EPMC492372 | biostudies-literature | 2004 Aug

REPOSITORIES: biostudies-literature