FIG. 2.

HPLC analyses of metabolites produced by P. putida CBB5 resting cell suspensions. CBB5 was cultivated in soytone-supplemented M9-caffeine medium. The cells were washed and resuspended at an OD₆₀₀ of 4.0. The following compounds (1 mM) were then added to cell suspensions: (A) caffeine, (B) theobromine, (C) 7-methylxanthine, (D) paraxanthine, (E) theophylline, and (F) 3-methylxanthine. The identities of the metabolites produced are as follows: metabolite I, paraxanthine; metabolite II, theobromine; metabolite III, 7-methylxanthine; metabolite IV, xanthine; metabolite V, uric acid; metabolite VI, 1,3-dimethyluric acid; metabolite VII, 1-methyluric acid; and metabolite VIII, 3-methyluric acid. Physical characteristics of these metabolites are shown in Table 1.