Industrial Applications of Caffeine Degradation by Pseudomonas sp.

Abstract

Caffeine is a purine alkaloid naturally present in over 50 plant species with coffee beans, tea leaves and cocoa beans as its main sources. Caffeine majorly enters human system through tea and coffee which are used as the customary drinks throughout the world. High intake of caffeine causes a number of physiological effects on human body. Caffeine also has environmental consequences as effluents released from coffee and tea processing industries are rich in caffeine and pollute nearby water bodies and landmasses affecting natural eco-system. Therefore, decaffeination becomes important from health and environment perspective. Conventional methods of decaffeination include solvent extraction procedures which are toxic, expensive and non-specific. Microbial caffeine degradation can overcome these disadvantages as they are safe and eco-friendly. In this study, induced cells of Pseudomonas sp. were used to degrade caffeine in the effluent collected from Theni unit of Tata Coffee’s Instant Coffee Division and in commercially available tea samples from AVT. Caffeine (0.1 g/l) in the effluent was degraded completely within half an hour when pH of the effluent was adjusted to 7.8 and 8 g/l of induced Pseudomonas cells were used. Among various matrices used for immobilizing Pseudomonas sp., calcium alginate was found to be the best degrading 93 % of caffeine in 3 h when 18 % inoculum was used. Several studies were also done to show that caffeine in tea samples can be effectively removed without significant reduction in polyphenol content by sequential addition of induced Pseudomonas sp. This study has shown that Pseudomonas sp. is an efficient candidate for development of biological decaffeination techniques.