Hi everyone,

I'm working with a Saccharomyces cerevisiae strain carrying a gal80Δ deletion, with genes expressed under GAL promoters. In this background, the GAL promoters can be active even without galactose, as long as glucose repression is relieved.

The protocol I'm following uses 2% glucose and notes that GAL promoter activity increases as glucose is depleted. However, I'm working with a very low-expressed gene, so I'm looking to improve expression by changing the carbon source.

This strain grows slowly in general, and particularly poorly on galactose. Are there any alternative carbon sources that support GAL promoter de-repression but allow for better growth than galactose?

Thanks in advance!