Saccharomyces cerevisiae
Saccharomyces cerevisiae (also called baker's yeast or brewer's yeast) is a species of yeast used to rise dough in baking bread and to convert sugar into alcohol in alcoholic beverages. Multiple strains of this yeast have been isolated, with some more appropriate for certain uses than others; such as higher alcohol tolerant strains being better for beverages, or matching taste profiles. For example, active dry yeast packets in a grocery store are the same species of yeast used to make cider, but that strain may die off when the alcoholic level starts rising and may make a "bready" tasting cider.
Nutritional yeast
Nutritional yeast is a commercially available Saccharomyces cerevisiae yeast product, typically grown on a substrate of molasses but is then pressed on heated rollers to compress into flakes and kill (typically labeled as inactive when killed). Nutritional yeast is often fortified with vitamins, such as Vitamin B12, which gives nutritional yeast a golden color. Nutritional yeast is not appropriate for using in baking or brewing as the yeast is no longer living.
Potassium sorbate will kill this yeast species.[1]
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