Growth characteristics and degradation kinetics of Arthrobacter sp. strain B1 and Alcaligenes sp. strain B5 in carbon-free MSM supplemented with different concentrations of indole. Circle, 0.2 mM; shaded triangle, 0.5 mM; shaded circle, 1.0 mM; square, 2.0 mM; shaded square, 5.0 mM. Growth of strain B1 (a), indole depletion by strain B1 (b), growth of strain B5 (c), and indole depletion by strain B5 (d)