Optimization of the environmental and physiological factors affecting microbial caffeine degradation and its application in caffeinated products
El- Mched F, Olama Z and Holail H
Journal Title:Basic Research Journal of Microbiology
Ten bacterial isolates were tested for their ability to utilize caffeine as the sole source of carbon and nitrogen source. The isolates identified as Pseudomonas stutzeri Gr 21 ZF showed 59% of 1.2 g/l caffeine degradation in 24 hrs when caffeine was used as the sole source of carbon and nitrogen source. In this study, the physical parameters viz, incubaton time, temperature, culture volume, inoculums size and pH were carried out to select a suitable conditions that lead to maximum caffeine degradation. The optimum values were found to be 48hrs, 50 ml, 3ml and 7 respectively. In the presence of sucrose (5g/l), 80.1 % degradation of caffeine was achieved in 48 hrs. The addition of inorganic source NH4Cl2 and KNO3 increase the caffeine degradation to 80.2% and 86% respectively. The critical medium components viz: Na2HPO4, KH2PO4, caffeine, sucrose, MgSO4.7H2O, CaCl2, Fe2+ affecting the caffeine degradation were determined by Plackett- Burman design. The optimum concentration that lead to 99.07% of caffeine degradation with 10% of crude enzyme were found to be 0.2 g/l; 2.6 g/l; 0.3g/l; 0.6 g/l; 10 g/l; 5g/l and 0.02% respectively Keywords: Caffeine degradation, microbial degradation, medium composition, Plackett-Burman.