The effect of oxygen on the growth and metabolism of the aerobic thermophilic actinomycete Micromonospora vulgaris.

In the presence of pure oxygen at one atmosphere pressure Micromonospora vulgaris is unable to form in liquid media a surface pellicle of growth-bearing aerial mycelium. The production of bottom growth is either unaffected or stimulated by oxygen. Vegetative mycelium which develops from spores in Warburg vessels has an oxygen uptake that is similar in the presence of air or oxygen. Aerial mycelium, harvested from growths in air, shows marked differences as regards oxygen uptake in the presence of air or oxygen; oxygen is inhibitory. Some evidence is presented to show that the effect of oxygen may be connected with the inactivation of essential -SH groups of thiol enzymes.