Abstract
This paper reviews the progress in the technology for manufacturing 5'-inosinic and 5'-guanylic acids as flavor-enhancing agents. It is only past 25 years from the beginning of their commercial production. Today, there are two ways for their production : One is degradation of ribonucleic acid from yeast and the other, fermentation from sugars using bacterial mutants. It is difficult to say now which process is better, because both processes include some severe problems to solve for the further technological development.
The keys for the further development of the degradation process are (a) availability of ribonucleic acid from methanol bacteria produced as single cell protein, (b) development of a bioreactor consisting of immobilized enzyme systems, and (c) evaluation of utility values of 5'-uridylic and 5'-cytidylic acid as the byproducts. The keys for the fermentation process are (a) increase in the productivity of nucleosides or 5'-nucleotides by strain improvement by means of gene engineering techniques, and (b) development of a bioreactor using immobilized cells. They are now on the way of research and development in the third stage of the progress in the technology for manufacturing flavor-enhancing 5'-ribonucleotides.
