Effects of arginine on growth and in prolonging longevity of corn stunt spiroplasma in vitro.

Abstract

Growth of corn stunt spiroplasma (CSS) in a medium containing 0-47 mM arginine increased with increasing arginine concentrations. Plotting specific growth rates of CSS at 0-94mM arginine resulted in a hyperbolic curve. At low arginine concentrations, specific growth rates of CSS were proportional to arginine concentrations; maximum growth rate occurred at 47mM arginine. Numbers of cells and colony-forming units in medium with 47mM arginine were two-fold greater than in medium without arginine. Helicity of CSS in medium with 0, 12, 24, and 47 mM arginine was lost by 8, 12, 14, and 15 days, respectively, after inoculation. Helicity was restored to 8-day-old cultures by addition of 47mM arginine. The growth-stimulating effect of arginine was inhibited or obscured when 10-20% serum was added to the medium. Addition of rifampicin also inhibited the growth-stimulating effect of arginine.