Development of a pH-controlled fed-batch system for budding yeast.

In the manufacturing of baker's yeast by aerobic fed-batch systems, continuous assessment of the state of the process is necessary for regulating the flow rate (on/off) for growth medium addition. A new, simple method for the fed-batch yeast process has been developed. It is based on pH changes as a suitable parameter for regulating the feed of fresh concentrated medium in response to metabolic activities of the yeast population. Experimental results have shown that it enables the attaining of high cell density with both high productivity and high yields.