Isolation of Bacillus Subtilis CTB04 as A New Biocatalyst for the Synthesis of Paraxanthine and Theobromine from Caffeine Substrate.

Background and Objectives: Microorganisms are known as an important biocatalysts for green chemistry which can be used beneficially for production of medically and pharmaceutically important compounds such as the bromine and paraxanthine through caffeine biotransformation. The aim of this study was to determine the bacterial subtypes which are able to use as a new biocatalyst for the synthesis of high-value added dimethylxanthines from caffeine as low-cost substrate. Material and Methods: In this experimental study, twenty-one bacterial strains isolated according to their ability to degrade caffeine using enrichment technique. Primary screening was performed by Thin Layer Chromatography (TLC). The selected strain characterized based on phenotypic analysis and also amplification of 16S rDNA gene. Biotransformation mixtures were quantified for produced methylxanthines by High Performance Liquid Chromatography (HPLC) technique. Results: Among the 21caffeine-degrading bacterial cultures, the resting cells of B. subtilis strain CTB04 are reported to be able to convert caffeine into the bromine and paraxanthine. The results showed that the strain CTB04 was capable of converting 2.5 g/l of caffeine to 1.35 g/l paraxanthine with molar yield (58.2%) and 0.66 g/l of the bromine with a 28.4% molar yield after 96 h biotransformation. Conclusion: There was a dual approach for bioremediation of the toxic caffeine from environment and a way for the production of pharmaceutically dimethylxanthines such as the bromine and paraxanthine as well. [ABSTRACT FROM AUTHOR]