Theoretical conversion yields for penicillin synthesis.

The efficiency of conversion of the carbon-energy source to product is of primary importance in many fermentation processes. In order to assess the efficiency of a process, one must know how close the actual conversion yield is to the theoretical maximum. Theoretical conversion yields are useful, therefore, as guides in improving a process. This knowledge is particularly important today because the cost of raw materials is rapidly rising. In this study, the biochemical pathway of penicillin synthesis was used to estimate the theoretical yield of penicillin from glucose, ammonia, and sulfate. These values are compared with experimental data from the literature. An analysis of the role of glucose in the synthesis of cell mass and penicillin and in the maintenance of cells makes it possible to assess the efficiency of carbon-source utilization and to direct further advances in penicillin fermentations.