Abstract
DM1 (Mucoid M) grown from Mutabile-type variant Murase originates a galactose resistant mutant of dwarf colony type. This mutant is resistant to galactose and differed from DM1 which is very sensitive to galactose. This kind of mutant was also found in Escherichia as well as in Salmonella. From the above reasons, this mutation is believed to be common among enteric bacteria and so it was designated as DMT1 in relation to DM1. Various characters of this mutant were investigated. The results obtained were as follows.
1) Colonies of DMT1 on plane agar plate and even on galactose agar plate are dwarf type in size.
2) Differed from DM1, DMT1 does not absorb galactose from the medium.
3) DMT1 is not motile as well as DM1.
4) In the acidagglutination reaction of Michaelis, the result of DMT1 is quite comparable to that of DM1.
5) In fermentation test with various carbohydrates, the results of DMT1 show the similarity to those of DM1.
6) DMT1 has tendency to restrain gas production in the fermentation of carbohydrates. And this kind of character is not influenced by the kinds of carbohydrates.
7) Sensitivity of DM1 to Na2SO3 is transmitted to DMT1, just as it is.
8) DMT2 originates MT-like mutant.
9) It is not easy to explain directly the relationships between DM1 and DMT1 from the serological point of view, but MT-like organism which was grown from DMT1 seems to belong to the same species with DM1 in the agglutination reaction in case of Salmonella. This also explains the relationships between DM1 and DMT1 indirectly.
From the above findings, it is believed that DMT1 is a new type of mutant which belongs to the Mutabile-type variation of Murase.
