On Thu, 14 Dec 1995, Tomas Drgon wrote:
> In article <30CCB9D5.4EAC at medcor.mcgill.ca>, Greg Cosentino
> <Cosentino at medcor.mcgill.ca> 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?
>> 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.
>> Tomas Drgon
> Signature under construction...
>>The same thing has already happened with me, and the yeast GROWTH very
well. I don't know, but I think it dependens on the strain you are
working on. If it has a lot of carbohidrates stored (into itself cell), I
think it should growth. But, the agar quality is a problem too. Why don't
you try wash the agar before preparing the medium?