I transformed my Pichia yeast with linearized plasmid and got colonies. I streaked them out and verified by PCR that my gene was present. I also streaked out X33 Pichia yeast (untransformed). When I inoculated YPD (which has dextrose) they grow fine, but they won't grow in BMGY (which has glycerol). My media is all freshly made up, and I have been over the recipes again an again. What can I do to get the yeast to grow?