Tryptophansynthase in Phycomyces blakesleeanus, Teil II: Tryptophansynthaseaktivität des Pilzes in Abhängigkeit von Lichtbedingungen und vom Zinkgehalt des Kulturmediums

Abstract

Abstract Tryptophan synthase in Phycomyces blakesleeanus. Part II: Activity of tryptophan synthase in Phycomyces blakesleeanus depending on the light and the content of zinc ions in the culture medium Five‐day‐old cultures of Phycomyces blakesleeanus show notice‐able differences in the phenotype, depending on the culture conditions (permanent light, permanent dark, zinc deficiency, zinc sufficiency) and related to the distribution of tryptophan synthase activity between mycelium and sporangiophores. Permanent light and the presence of zinc ions in the medium during culturing have an antagonistic influence on the tryptophan synthase. The activity of the enzyme is being reduced in the sporangiophores and increased in the mycelium by the influence of light, while zinc ions in the culture medium increase the activity in the sporangiophores at simultaneous reduction in the mycelium.The importance of tryptophan synthase and tryptophan for the development of the fungus in relation to the metabolism of indole acetic acid is discussed.