FIG. 4.

Expression of arsA, AR synthesis, and encystment in two different media, Burk-sucrose medium (vegetative growth; open symbols) or Burk-butanol (encystment induction medium; closed symbols). (A) β-Glucoronidase activity of strain OV11 containing an arsA::Tn5-gusA reporter fusion. (B) Accumulation of alkylresorcinols over time in A. vinelandii SW136. (C) Percentages of encystment of strains SW136 and OV11, measured as desiccation resistance for 5 days. The inocula were incubated for 24 h on liquid Burk-sucrose, washed with Burk's medium with no carbon source, and transferred to plates with the corresponding medium (at time zero). These data are the means of triplicates, and the error bars represent the standard deviations. One unit of β-glucoronidase activity corresponds to 1 nmol of substrate 5-bromo-4-chloro-3-indolyl-β-d-glucuronic acid hydrolyzed per min per mg of protein.