In article <30CCB9D5.4EAC at medcor.mcgill.ca>, Greg Cosentino
<Cosentino at medcor.mcgill.ca> wrote:
> Any ideas to explain growth of the yeast in
> the absence of carbohydrate?
and Tomas Drgon replied:
>They should not grow. I tend to think, that there are residual
>amounts of sugars in your agar. I tried to grow wildtype yeast (S.c)
>in liquid YPD where I by mistake did not add glucose or any other
>carbon source, and i have got definitely NO growth.
>On the other hand, for some yeast the carbon skeletons coming from
>the degradation of amino acids might be enough to feed Krebs cycle to
>produce enough NADH for respiratory chain.
I have to disagree. I have tried to grow wildtype Sacharomyces
cerevisiae (W303) in liquid as well as on solid media without glucose
or any other saccharide (complex YP or even semisyntetic YNB
suplemented just by several aminoacids) and the yeasts did grow. A
little bit slower, perhaps, but they did. I think they can use
certain aminoacids (not all of them) as carbon sources. For that, of
course, they need Krebs cycle and respiration, so petites will not