Effect of cultivation temperature, clomiphene, and nystatin on the oxidation and cyclization of chanoclavine in submerged cultures of the mutant strainclaviceps purpurea 59

Abstract

Submerged cultures ofClaviceps purpurea 59 produce predominantly tricyclic chanoclavine and chanoclavine-I-aldehyde; formation of the tetracyclic agroclavine and elymoclavine is limited to 20%. The production cultures were characterized by the oxidation index oi (100% chanoclavine/% chanoclavine) and cyclization index ci (% agroclavine +% elymoclavine/% chanoclavine-I-aldehyde), expressing two functions of chanoclavine cyclase. Both indices were influenced by cultivation temperature and membrane agents. At 20°–24°C, clomiphene increased oi and ci; at 28°C and more it increased oi only. At 24°C nystatin increased oi and decreased ci. During cultivation of vegetative inocula and production cultures at various temperatures (24°, 28°, and 33°C), the lower cultivation temperature of the inoculum increased ci of the production culture with the higher temperature. The higher cultivation temperature of the inoculum decreased oi and particularly ci of the production culture with the lower temperature. In production cultures cultivated from the inoculum of an identical temperature, oi decreased to 50% with increasing temperature above 24°C, whereas ci decreased continuously. The role of the chanoclavine cyclase conformation as a membrane enzyme is discussed.