Which of the following is not a prokaryote?
Saccharomyces
Prokaryotes are unicellular organisms that lack a well defined nucleus and membrane bound organelles.
Nostoc and Oscillatoria which are photosynthetic cyanobacteria and heterotrophic bacterium, Mycobacterium are prokaryotic in nature.
Yeasts (Saccharomyces) are unicellular fungi. They are eukaryotic in nature containing a well defined nucleus and membrane bound organelles.