But while few emanations from the kitchen are quite as tantalizing as the yeasty aroma of baking bread, most people agree that pure yeast tastes pretty bad. Other genera of yeast also have practical uses. Some can use hydrocarbons, such as petroleum, as a carbon source. These organisms can literally convert petroleum into protein. They are being used to remove petroleum as a pollutant from the environment and to convert low-grade hydrocarbons into protein for consumption by animals.
Yeast can indeed be germs.
While in normally healthy people it is harmless, in those whose immune response is weakened it can become infectious and turns into a serious pathogen. These infections are particularly hard to control in humans because yeast metabolism is so similar to ours. Drugs that are toxic to the yeast are also toxic to people. Another particularly nasty pathogenic yeast, Cryptococcus neoformans , produces a life-threatening meningitis. This cell buds, the bud grows to nearly the size of the parent cell, the nucleus divides, and the two cells separate into two unbudded cells.