I use S. cerevisiae for yeast display and I suspect I have a contamination in my cultures but it is not obvious and I don't currently have a microscope in the lab.
I grow in minimal media selecting for Trp auxotrophy complementation in the transformed yeast.
Recently my yeast cultures don't seem to display and they are growing slowly and have a less pungent smell compared to S. cerevisiae. They don't smell like E. coli either and colonies on plates have same colour and shape as S. cerevisiae as far as I can tell.
What are the common contaminants yeast scientists see and how to deal with them?
I know about Candida... is microscope the only way to identify a contamination from Candida or other species?
Thank you