ABSTRACT
Various kinds of amino acids are used in large amounts as food seasonings, food additives, and feed additives. Several amino acids are important as raw materials of medicines, artificial sweeteners, and other chemicals. In this chapter, the author adopts the transductional method for amino acid-hyperproducing strains of Serratia marcescens. Generally, the following criteria are required for the microbe being selected: fast cell growth and abundant cell mass; high sugar-assimilating activity; known biosynthetic pathway for the amino acid of interest and elucidated regulatory mechanisms for the biosynthesis; and genetic methods available for strain construction. The author succeeds in the construction of several amino acid-hyperproducing strains of Serratia marcescens. The author develops several industrial methods for amino acid production using Serratia marcescens. Although genetic approaches allow us to construct interesting strains more rationally than ever, we cannot avoid the numerous and tremendous trial-and-error work to obtain our final goals.
