With the newfound knowledge that yeast was a living organism and the ability to
isolate yeast
strains in
pure culture form, the stage was set for commercial production of baker's that began around the turn of the 20th century.
«It's a very complicated picture and the laboratory model of just taking one
isolated chemical and giving it to a genetically
pure strain of rats in clean cages, clean air and clean water and seeing what it does just doesn't come close to mimicking the human situation,» she said.