Decaffeination and Measurement of Caffeine Content by Addicted Escherichia coli with a Refactored N-Demethylation Operon from Pseudomonas putida CBB5

作者：Quand Erik M; Hammerling Michael J; Summers Ryan M; Otoupal Peter B; Slater Ben; Alnahhas Razan N; Dasgupta Aurko; Bachman James L; Subramanian Mani V; Barrick Jeffrey E^*

来源：ACS Synthetic Biology, 2013, 2(6): 301-307.

DOI：10.1021/sb4000146

• decaffeination
• N-demethylation
• bioremediation
• xanthine alkaloid
• theophylline

The widespread use of caffeine (1,3,7-trimethylxanthine) and other methylxanthines in beverages and pharmaceuticals has led to significant environmental pollution. We have developed a portable caffeine degradation operon by refactoring the alkylxanthine degradation (Alx) gene cluster from Pseudomonas putida CBB5 to function in Escherichia coli. In the process, we discovered that adding a glutathione S-transferase from Janthinobacterium sp. Marseille was necessary to achieve N-7-demethylation activity. E. coli cells with the synthetic operon degrade caffeine to the guanine precursor, xanthine. Cells deficient in de novo guanine biosynthesis that contain the refactored operon are %26quot;addicted%26quot; to caffeine: their growth density is limited by the availability of caffeine or other xanthines. We show that the addicted strain can be used as a biosensor to measure the caffeine content of common beverages. The synthetic N-demethylation operon could be useful for reclaiming nutrient-rich byproducts of coffee bean processing and for the cost-effective bioproduction of methylxanthine drugs.

• 出版日期2013-6