loading page

Biocatalytic Production of 7-Methylxanthine by a Caffeine-Degrading Escherichia coli Strain
  • Meredith Mock,
  • Ashley Cyrus,
  • Ryan Summers
Meredith Mock
The University of Alabama

Corresponding Author:[email protected]

Author Profile
Ashley Cyrus
The University of Alabama
Author Profile
Ryan Summers
The University of Alabama
Author Profile


7-Methylxanthine, a derivative of caffeine (1,3,7-trimethylxanthine), is a high-value compound that has multiple medical applications, particularly with respect to eye health. Here, we demonstrate the biocatalytic production of 7-methylxanthine from caffeine using Escherichia coli strain MBM019, which was constructed for production of paraxanthine (1,7-dimethylxanthine). The mutant N-demethylase NdmA4, which was previously shown to catalyze N 3-demethylation of caffeine to produce paraxanthine, also retains N 1-demethylation activity toward paraxanthine. This work demonstrates that whole cell biocatalysts containing NdmA4 are more active toward paraxanthine than caffeine. We used four serial resting cell assays, with spent cells exchanged for fresh cells between each round, to produce 2,120 μM 7-methylxanthine and 552 μM paraxanthine from 4,331 μM caffeine. The purified 7-methylxanthine and paraxanthine were then isolated via preparatory-scale HPLC, resulting in 177.3 mg 7-methylxanthine and 48.1 mg paraxanthine at high purity. This is the first reported strain genetically optimized for the biosynthetic production of 7-methylxanthine from caffeine.
30 Apr 2022Submitted to Biotechnology and Bioengineering
05 May 2022Submission Checks Completed
05 May 2022Assigned to Editor
15 May 2022Reviewer(s) Assigned
04 Jul 2022Review(s) Completed, Editorial Evaluation Pending
04 Jul 2022Editorial Decision: Revise Major
12 Aug 20221st Revision Received
12 Aug 2022Submission Checks Completed
12 Aug 2022Assigned to Editor
13 Aug 2022Review(s) Completed, Editorial Evaluation Pending
13 Aug 2022Editorial Decision: Accept
12 Sep 2022Published in Biotechnology and Bioengineering. 10.1002/bit.28212