Alternative respiration of fungus Phycomyces blakesleeanus.

Respiratory characteristics of germinating spores, developing mycelium and mitochondria of the fungus Phycomyces blakesleeanus were investigated by means of oxygen Clark-type electrode. The effects of respiratory inhibitors and metabolic compounds on oxygen consumption were tested. It was demonstrated that P. blakesleeanus apart of cyanide-sensitive respiration, CSR, possess alternative respiration, (cyanide-resistant respiration, CRR) which is constitutive and whose capacity decreases during development. Maximum is observed for activated spores where CRR capacity is significantly greater than CSR. After treatment with antimycin A, a third type of respiration insensitive to antimycin A and low concentration of SHAM (sufficient for inhibition of CRR), but sensitive to cyanide and high concentration of SHAM, has been expressed.