Degradation of caffeine by Pseudomonas monteilii KRM9

Aims: The objective of this research was to isolate caffeine-degrading bacteria from coffee pulp waste in Indonesia and characterize their caffeine degradation activity. Methodology and results: The caffeine-degrading bacteria were isolated from coffee pulp wastes of Coffea arabica and C. canephora. These isolates were selected based on their caffeine degradation activity. The identification and biochemical properties of the best isolate were conducted via 16S rDNA sequence analyses and by using the Microbact kit. Meanwhile, caffeine degradation activity of this bacteria was analyzed by using LC-MS/MS. The results indicated that fourteen bacterial isolates were able to degrade caffeine. The highest caffeine degradation activity was performed by isolate KRM9 at the rate of 99.26 ± 0.01%, on a caffeine medium after 24 h of incubation. Based on the 16S rDNA analyses, the KRM9 isolate was identified as Pseudomonas monteilii. Till present, this species has not been reported as a caffeine-degrading bacterium. However, LC-MS/MS analysis indicated that caffeine was degraded by P. monteilii KRM9 and theobromine was not the secondary metabolite of caffeine degradation. Conclusion, significance and impact of study: Pseudomonas monteilii KRM9 was detected as a new isolate of caffeine-degrading bacteria. This bacterium can be introduced as an agent to degrade caffeine from coffee pulp waste. It is expected that further research can be conducted on the overall mechanism of caffeine degradation by P. monteilii KRM9.