Candida utilis NCYC 321 was grown in steady-state culture in a chemostat under glucose limitation or NH4+ limitation at temperatures of 30, 25, 20, and 15 C and at dilution rates (equal to growth rates) in the range of 0.35 to 0.05 hr'1. Deoxyribonucleic acid contents of cells grown under the various conditions remained approximately constant, but the contents of several other cell components varied. Over the range of 30 to 15 C, the greatest differences were in the ribonucleic acid (RNA) and protein contents of cells grown under NH4+ limitation, which increased