growth

[Dave Eide]

In message <Pine.3.03+.9502161359.A25514-9100000 at fhs.csu.McMaster.CA> Kathy 
Shire writes:
> 
> Hi,
> 
> Has anyone ever had problems growing yeast (with 2 selectable plasmids, 2u
> ori) in minimal medium?  My yeast grows well on plates and really slow
> (double time approx. O/N) in liquid medium (growth stops after 2 days at
> approx. OD600=1).  Apart from the yeast getting dizzy in the shaker, there
> shouldn't be any difference btwn liquid cultures and growth on solid medium.
> My LIQUID Bgal assays are not working out...HELP!
> 
> The shaker is at 30C and 225rpm.
> 
> Thanks for being there,
> 
> Kath
> 
> 
> 
>

Hi Kath,

I've always felt that there was a BIG difference between liquid culture and 
growth in colonies.  In liquid, the cells are dispersed and have equal access to
nutrients.  In a colony, it seems like the cells in the center of the colony may
be anoxic and have less available nutrients.  Furthermore, the cells might also 
be able to generate lower local pH in colonies than in liquid.  These are just 
impressions and I can't back them up with any data.

So, why don't your cells grow well in liquid when they do on plates?  We have 
strains that are defective for iron uptake that grow well on plates but not in 
liquid and believe it to be pH effects.   What's the genotype of your strain?  

Dave Eide   


----------------------------------------------------------------------------
David Eide
Department of Biochemistry and Molecular Biology
University of Minnesota-Duluth
10 University Drive
Duluth,  MN  55812-2487
USA
phone: 218-726-6508,  fax: 218-726-6235,  email: deide at ub.d.umn.edu