TAXONOMICAL STUDIES ON GLUTAMIC ACID-PRODUCING BACTERIA

Abstract

The taxonomical characters of 208 strains of glutamic acid-producing bacteria and the base compositions of DNA solated from representative strains were studied.These organisms are, in general, Gram-positive, non-sporulating, non-motile, ellipsoidal spheres to short rods, pleomorphic and require biotin for growth and accumulate aerobically large amounts of L-glutamic acid. Some minor differences are found in physiological characteristics of these strains.All strains examined are considered to belong to a single or very closely related species in genus Corynebacterium. They can beclassifiedphysiologically into 12 types. The guanine plus cytosine (G-C) content of DNA of these strains is varied as represented by three groups, groups I, II and III, G-C contents of which are 53, 56 and 65%, respectively.Group I contains most of the glutamic acid-producing strains and consists of the strains of the physiological types 1 to 10. On the other hand, those strains of groups II and III, which belong to physiological types 11 and 12, are different from those of group I in base composition of DNA. Although it is questionable whether the strains belonging to groups II and III could be assumed to belong to the same species as those belonging to group I, we consider it admittable to name all these organisms Corynebacterium glutamicum laying a stress on their common character of glutamic acid production.