Auxithals Synthesized by Some Filamentous Fungi.

Since 1869 when RAULIN reported that Aspergilluts niger excreted some growth-promoting substances into its medium, a number of investigators have studied the phenomenon of auxithal synthesis by fungi. For a comprehensive review of this the reader is referred to FRIES (2) and SCHLENKER (7). The writers (5) have referred briefly to this subject; the present paper reports a more exhaustive study. The following six organisms were used as sources of auxithals: Rhizopits suinus, Fusarium niveurn, Phytophthora erythroseptica, Phycomyces blakesleeanuts, Pythiomnorpha gonapodioides, and Matcor ramannianus. The first two fungi thrive in synthetic media without the addition of any growth substance; Phytophthora erythroseptica cannot grow without thiamin; Phycomnyces blakesleeanuts grows either in the presence of thiamin or of a mixture of pyrimidine and thiazole (thiamin moieties), Pythiomorpha gonapodioides grows in the presenee of pvrimidine alone as well as in the presence of thiamin; Mucor rarnannianus requires only thiazole for growth, but it does very well in the presence of thiamin.