The yeast used in the manufacture of bread is Saccharomyces cerevisiae. This species of yeast plays a crucial role in bread-making by fermenting sugars in the dough to produce carbon dioxide gas, which causes the dough to rise. Saccharomyces cerevisiae is favored for its ability to efficiently ferment sugars and tolerate the conditions present in bread dough, such as low pH and high osmotic pressure. Its use in bread-making dates back centuries, and it remains the primary yeast species employed in commercial bread production worldwide. Saccharomyces cerevisiae is also extensively used in other fermentation processes, including brewing, winemaking, and biofuel production, due to its versatility and ease of cultivation. Its widespread use in various industries underscores its importance as a key microbial agent in biotechnology and food processing, contributing to the production of a wide range of products essential to human life.