Secondary Factors in Fermentation Processes

Abstract

Publisher Summary This chapter illustrates the secondary factors in fermentation processes. The successful outcome of a fermentation process is, in most cases, conditioned primarily by factors that influence the growth of the organism concerned with the particular process. The propagation of yeast for food or fodder is a typical case in which optimal conditions for the reproduction of the yeast cell are obligatory for the process at large. In other cases where the industrial interest lies more in the production of a certain metabolite, it is rather the suboptimal conditions for growth and reproduction, and not the optimal conditions as expressed by dry-weight determination, that have to be provided in order to secure the maximum yield of the desired metabolite. Several cases in which the presence of a certain chemical factor in the nutrient medium substantially influences the fate of the fermentation process have been reviewed. Except for the occasional data, little is known of secondary factors that may influence processes such as the transformation of steroids, or the production of enzymes, although, considerable developments can be expected in the near future.