Previously isolated strain of Pseudomonas sp. has the capability of utilizing caffeine as the sole source of carbon and nitrogen and degrading caffeine at higher concentrations (>10 g l(-1)). In this study, an assay has been developed to study the enzymatic conversion of caffeine to subsequent methylxanthines by cell free extracts of Pseudomonas sp., the activity of which has been stabilized by use of stabilizers in the lysis buffer. Growth of the strain in various methylxanthines and later enzyme assay demonstrated that the enzyme(s) involved in degradation of caffeine and other methylxanthines were inducible in nature. The results also indicated that more than one enzyme are involved in degradation of caffeine to xanthine, which constitute the primary steps in bacterial caffeine catabolism.
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