Degradation and product analysis of caffeine and related dimethylxanthines by filamentous fungi

Abstract

Twenty strains of filamentous fungi were tested for their ability to grow on a liquid medium containing caffeine (1,3,7-trimethylxanthine) as a sole nitrogen source. Seven strains which were able to grow on caffeine belong to the #Aspergillus and #Penicillium genuses. They all presented the same degradation pathways but varied in the efficiency by which degradation took place. Caffeine was first demethylated in position 7 ; this lead to the formation of theophylline (1,3-dimethylxanthine). This compound was next demethylated in position 1 to give 3-methylxanthine. All these strains were also able to grow on theophylline, theobromine (3,7-dimethylxanthine), and paraxanthine (1,7-dimethylxanthine) as a sole nitrogen source. All degradation intermediates detected were methylxanthines. (Résumé d'auteur