Abstract
In the studies of fungistatics produced by Rhizopus and Trichoderma lignorum the active substances have not yet been isolated, but the following characteristics were recognized:
1) The antifungic power of the culture solutions is shown after the formation of spores, and at the same time their pH decreases. It is supposed that the antifungic power has some relation to the formation of spores and to the pH of the medium.
2) The antifungic power is not found in the filtrates of the culture solution when CaCO3, is added so as to make pH 6. So the antifungics may be a kind of organic acids.
3) (NH4)2SO4 is the most effective one among the inorganic salts which are used as the source of N.
4) These substances are not or little produced in the medium whithout MgSO4 and also the growing of these fungi is worse.
5) These substances have stabilities against heat (100°C) and have almost the same solubilities for various organic solvents. Therefore, it is presumed that these substances are the same.
