Abstract
One percent of BTB pepton agar suspended with mutabile-type variant (Murase) was used as a standard seed layer as similar to that of penicillin assay. The diameter of inhibition zone. appeared around a galactose paper disc or a cup in growths of mutabile-type variant was measured. The results were summarized as follows:
1. The diameter of inhibition zone was varied according the duration of diffusion time of galactose into the medium, that is, the diameter of the zone increased in length when the concentration of lactose was high, while it decreased or disappeared when the concentration was low. So, it was appeared that inhibition zone will not formed when the concentration of galactose at the applied areas was under effective dose to produce inhibition zone.
2. when small amount of galactose which will not produce inhibiting zone was added previously to the seedlayer, the effect of galactose in the medium became more sensitive, then, in this assay, both doses of galactose which might be contained in the specimen and in the medium will sum up to the high concentration enough to form the inhibition zone or to enlarge a diameter of the zone. The sensitive amount of galactose measured in γ concentration became 4-8 times higher than that of standard medium.
This new findings could be applied to find the biological test of galactoside, antibiotics and blood samples in a test of liver functions and to the studies on enzymatic action of the microorganisms etc. Studies along this line are now under way and details will be published in near future.
