Greg Cosentino wrote:
> Hi Netters,
>> I am checking the ability of a yeast strain to grow on
> non-fermentable carbohydrates (glycerol, ethanol, and acetate)
> compared to glucose. As a lark, I also streaked my yeast onto
> control plates composed of yeast extract and peptone but with no
> carbohydrate at all. It seems that the strains capable of aerobic
> growth also grew in the absence of any carbohydrate whatsover, but
> the petite mutants didn't grow. The seed cultures were made in
> liquid YPD media and then washed extensively with water prior to
> plating so I wouldn't carry over any of the glucose containing media
> when I plated them. Any ideas to explain growth of the yeast in the
> absence of carbohydrate?
The cells could very well be using amino acids (possibly from broken down protei
ns) to grow (as Tomas Drgon ponted out later). When I was a Ph.D. student, I
tested the growth phenotypes of a yeast with a k.o. of a yeast gene (CPR3, a
mitochondrial cyclophilin). I found that not only did my yeast strains grow
on YP with no added carbon, they also grew on "Synthetic complete" (Cold Spring
Harbor version) with no added carbon. The growth was pretty awful (I didn't
measure rates, just looked at petri dishes), but they formed colonies nonethe-
less. This medium only consisted of yeast nitrogen base plus adenine, uracil,
and 14 amino acids. Sorry, I don't have a reference, nor do I expect this obser
vation to end up in a paper.
Ed Davis
NCI-FCRDC
P. O. Box B
Frederick, MD
Ph. 301-846-1564
