Journal des bioprocédés et des biotechniques

Optimization of Process Conditions for Biotransformation of Caffeine to Theobromine using Induced Whole Cells of Pseudomonas sp

Abstract

Sreeahila Retnadhas and Sathyanarayana N Gummadi

The obromine is a metabolic intermediate produced in caffeine degradation pathway by many bacterial species, which has potential applications in food and pharmaceutical industries. Conventional methods of Theobromine production from xanthine involve harsh physical and chemical conditions which are harmful to the environment. To overcome this, we employed biotechnological route to convert caffeine to theobromine by single demethylation reaction using induced cells of Pseudomonas sp. Initially we screened various divalent metal ions for the production of Theobromine by Pseudomonas sp. from caffeine. Co2+ and Ni2+ accumulates 400 and 100 mg/l of theobromine under initial reaction conditions (2 g/l caffeine, 8 g/l cell loading, pH 7.0,30°C). Co2+ was chosen for further optimization of reaction conditions for Theobromine production using response surface methodology. Data were fitted into a quadratic model and the optimal condition for theobromine production was found to be 3.2 g/l caffeine, 11.3 g/l initial cell loading and pH 7.0. Quadratic regression models were validated at the optimized conditions and the experimental theobromine produced 689.7 mg/l corresponds to the model predicted theobromine 729.4 mg/l. Theobromine production was further improved to 1.08 ± 0.10 g/l by optimizing the reaction temperature. This study reports highest production of theobromine from caffeine using induced cells of Pseudomonas sp. Induced cells are better suited for metabolite production as it is metabolically very active and can be re-used several times. Optimization of reactor parameters will enable us to make microbial production of theobromine feasible in industries at reduced cost.