Abstract
In the present study we have tried to find optimal cultural conditions for rapid growth and large yields of the actively growing A. laidlawii A cells. The earlier findings on the growth promotion of oleic and elaidic acids were confirmed. The modified Edward and Butler & Knight medium was superior to all other media tested when colony forming units were used as a measure of growth. The highest yields expressed as a total cell protein were obtained both in the elaidic acid—tryptose broth and in the Edward medium after 24 hours' growth. The cells grown in the basal tryptose broth appeared in the electron microscope as large (Ø 600–1000 nm) spherical bodies throughout the growth cycle. The addition of unsaturated fatty acids induced A. laidlawii A to divide and to multiply as smaller (Ø 300–500 nm) round bodies, connected with the active growth. On the basis of earlier findings and the present results it is suggested that the multiplication of A, laidlawii A occurs by division.