Yeast Culturing & Lag Times

[Tritech Research]

We have observed this and a related phenomenon of low recovery of
transformants following electroporation.  My hand-waving explanation
is that growth on YEPD causes this for two reasons.
1) there is no selection for genes required for growth on minimal,
so the fastest growing cells in the culture may be mutants, and
thus lots of the innoculum may be unable to grow at all on minimal.
2) even if the metabolic pathway genes are not mutated, they are
probably mostly repressed, since they are not required in YEPD,
thus it probably takes a while for them to get derepressed.

Just a guess - I'm sure someone else has the references...

Andy
tritech_research at lamg.com