Chemotaxis in Spirochaeta aurantia

Abstract

Cells of S. aurantia M1 suspended in isotropic buffer solution swam in nearly straight lines and appeared to spin around their longitudinal axis. Occasionally, cells stopped and flexed, and then resumed translational motility, usually in a different direction. The average cell velocity was 26 .mu.m/s. A quantiative assay for chemotaxis was used to test various chemicals for their ability to attract S. aurantia M1. The cells exhibited a tactic response toward 5 .times. 10-2 M D-glucose between 10.degree.-35.degree. C; the optimum response was at 25.degree. C. At 5.degree. C motility was not impaired, but D-glucose taxis was abolished. Chemotaxis toward D-glucose was stimulated by L-cysteine (2 .times. 10-4 M). D-Glucose, 2-deoxy-D-glucose, .alpha.-methyl-D-glucoside, D-galactose, D-fucose, D-mannose, D-fructose, D-xylose, maltose, cellobiose and D-glucosamine were effective attractants for S. aurantia M1. D-Galactose taxis and D-fucose taxis were induced by the presence of D-galactose in the growth medium. The amino acids tested did not serve as attractants. Growing cells of S. aurantia M1 exhibited an aerotactic response.