The Bacillus subtilis galE Gene Is Essential in the Presence of Glucose and Galactose

Bacillus subtilis is unable to grow by consuming galactose because it is unable to transport it into the cell. The transcription of galE is not influenced by galactose but is repressed by glucose. Galactose is toxic for galE-negative bacteria because it results in elevated levels of metabolic intermediates. These negative effects are reduced in galK and galT mutants. Glucose is also toxic for galE-negative strains.