Production of Cytochrome c by an Obligate Methylotroph,Methylomonas sp. YK 1

An obligate methanol-utilizing bacterium, Methylomonas sp. YK 1, was isolated and used as a cytochrome c producer. The strain was mutagenized so as to be resistant to metabolic inhibitors related to the function of cytochrome c. The strain, YK 56, which was derived as a KCN-resistant mutant contained 3 times the cellular level of cytochrome c compared to the parent strain. Optimization of the culture conditions for the mutant to enhance the cytochrome c productivity was performed. Peptone, succinate, l-malate or FeSO₄ · 7H₂O increased the productivity when added to the culture medium. Under the optimal culture conditions, strain YK 56 produced about 60 mg cytochrome c per liter when methanol and peptone were fed to the medium during the cultivation.