Clostridium acetobutylicum P262 had phosphotransferase systems for glucose and lactose, and the lactose system was inducible. When C. acetobutylicum P262 was provided with glucose and lactose, the cultures grew in a diauxic fashion, and glucose was used preferentially. Cells grown on lactose took up thiomethylgalactoside, and retained this non-metabolizable lactose analog for long periods of time. Because glucose inhibited thiomethylgalactoside uptake and caused the efflux of thiomethylgalactoside that had already been taken up, it appeared that C. acetobutylicum P262 had inducer exclusion and inducer expulsion mechanisms similar to those found in lactic acid bacteria.
Bibliographical noteFunding Information:
This research was supported by the US Dairy Forage Research Center, Madison, WI. F.D.-G. is grateful to Consejo National de Ciencia y Tecnolo-gia. Mexico, for their support.
- Catabolite regulation
- Clostridium acetobutylicum
- Inducer expulsion