絲状菌の發育を選擇的に阻止する抗生物質に就て(豫報)

Abstract

The author has isolated a fungus-like organism (RP) which grew scantily but showed inhibitory action among the colonies of Penicillum chrysogenum Q176 on a CZAPEK's agar plate. The culture filtrate of RP, besides Q176, retarded the growth of several strains of Penicilla and a strain of black Aspergilli, but had not activity against a strain of each species of Aspergillus oryzae, Rhizopus, and Mucor. Furthermore several type cultures of Aspergilli and Penicillia were tested for RP by the so-called streak plate method on koji-extract agar, It was found that all strains of Aspergillus flaves-oryzae, group, only one of the black Aspergilli, and two of Penicillia were not inhibited. Then classification of Aspergilli or Penicillia would be possible in view of their behaviors towards RP or its active substance (s). Even the strains considered as insensitive here, however, are also inhibited to a certain extent on CZAPEK's agar by RP. This fact suggests that the active substance (s) produced by RP might inhibit. the early stages of the cell-material syntheses by the above organisms from inorganic salts contained in, the medium. RP is willing to grow submerged in synthetic liquid media, such as CZAPEK's one, instead of surface growth, producing antifungal substance (s). Three thousand times dilution of the culture filtrate is not enough to make it inactive against a strain of black Aspergilli. The shaken culture have little advantage both on the growth of RP and on the formation of active substance (s). On the synthetic solid media, RP shows scant growth but develops deeply into the agar. RP has long and branching hyphae, of ca. 2.5 microns, having no septa. The masses of hyphae, namely the flocculent colonies, in liquid media, do not submit to lysis for a long time, and the culture broth is clear and not liable to change in reaction. Sporulation has not been definitely recognized. Against bactria, that is, Bacillus subtilis, Esherichia coli, and Staphylococcus aureus, the culture filtrate of RP is not active. The isolation of the active substance (s) and the more detailed study are to be reported in the following papers.