DM
1 (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 DM
1 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 DMT
1 in relation to DM
1. Various characters of this mutant were investigated. The results obtained were as follows.
1) Colonies of DMT
1 on plane agar plate and even on galactose agar plate are dwarf type in size.
2) Differed from DM
1, DMT
1 does not absorb galactose from the medium.
3) DMT
1 is not motile as well as DM
1.
4) In the acidagglutination reaction of Michaelis, the result of DMT
1 is quite comparable to that of DM
1.
5) In fermentation test with various carbohydrates, the results of DMT
1 show the similarity to those of DM
1.
6) DMT
1 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 DM
1 to Na
2SO
3 is transmitted to DMT
1, just as it is.
8) DMT
2 originates MT-like mutant.
9) It is not easy to explain directly the relationships between DM
1 and DMT
1 from the serological point of view, but MT-like organism which was grown from DMT
1 seems to belong to the same species with DM
1 in the agglutination reaction in case of Salmonella. This also explains the relationships between DM
1 and DMT
1 indirectly.
From the above findings, it is believed that DMT
1 is a new type of mutant which belongs to the Mutabile-type variation of Murase.
View full abstract