Saccharomyces cerevisiae (baker’s yeast) is the most important industrial microorganisms. This yeast is commonly used as a leavening agent in baking bread and bakery products, where it produces carbon dioxide from converting of the fermentable sugars present in the dough. Nowadays, industrial and chemical activities led to produce new compounds with new kinds of contamination in the environment. Discharge of untreated or partially treated industrial sewage has created the contamination problems of rivers and lakes such as drugs, oil, heavy metals, paints, pesticides and various chemical compounds in them. Hence, it is necessary to control and reduce the levels of these compounds in wastewater and bring them to permissible values. This study aims to study the bioconversion potential of commonly available Saccharomyces cerevisiae for the four textile dyes of of Reactive Red X-GRL 41 & Rhodamine are cationic dyes and Reactive Red 120 & Direct Red are anionic dyes Reaction mixtures for biotransformation of dyes included 25 mg/l dyes and 1% dried harvested cells of S. cerevisiae (bread’s yeast) were tested. Harvested dry and wet yeast were studied for this purpose. The results show that harvested cells of Saccharomyces cerevisiae are able to bioconvert dyes. RRX-GRL & RR120. are degraded by biotransformation 100% and Rirect Red 80 & Rhodamine are degraded by biotransformation <11% & within 72 hours in water at the room temperature. so the yeast can both cationic and anionic dyes or remove by biotransformation and or biotransformation not done.