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 o_i (100% chanoclavine/% chanoclavine) and cyclization index c_i (% 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 o_i and c_i; at 28°C and more it increased o_i only. At 24°C nystatin increased o_i and decreased c_i. During cultivation of vegetative inocula and production cultures at various temperatures (24°, 28°, and 33°C), the lower cultivation temperature of the inoculum increased c_i of the production culture with the higher temperature. The higher cultivation temperature of the inoculum decreased o_i and particularly c_i of the production culture with the lower temperature. In production cultures cultivated from the inoculum of an identical temperature, o_i decreased to 50% with increasing temperature above 24°C, whereas c_i decreased continuously. The role of the chanoclavine cyclase conformation as a membrane enzyme is discussed.