A peculiar example of bacterial antagonism

Summary

An example of antagonism has been described. The properties of the growth inhibiting bacterium have been investigated more closely. These appear to agree nearly fully with those of the genusGaffkya.

The development ofPasteurella avicida, Bacillus orpheus andStaphylococcus was strongly inhibited by this bacterium. Other species are less sensitive or insensitive.

After the theoretical problems have been discussed, which such investigations give rise to, it has been studied under which conditions Staphylococci are inhibited.

The occurrence of the inhibition effect depends on the stage of development either bacterium is in;Staphylococcus having developed completely it will not notably be acted upon. Initially inhibition of growth occurs along with dying off ofStaphylococcus. In a somewhat later stage the vitality remains unimpaired.

The inhibiting bacteria produce inhibiting substances merely in the first 24 hours. In the filtrate of a broth culture these are hard to detect. Their behaviour in agar plates makes it apparent that their action depends strongly on the concentration of the antagonist.

The durability of the inhibiting substances in the agar medium is not great. In all probability this depends on a volatibility of these substances.