Degradation of synthetic coffee wastewater using induced cells of Pseudomonas sp. NCIM 5235

Abstract

Coffee wastewater contains a high amount of caffeine, which causes adverse effects on the environment. Current treatment strategies focus majorly on overall chemical oxygen demand (COD) reduction and do not focus on caffeine degradation in wastewater. Though several techniques are available to degrade caffeine, biological methods are preferred as they are economical and eco-friendly. In this study, Pseudomonas strain NCIM 5235 was evaluated for its potential to degrade caffeine in synthetic coffee wastewater. Uninduced cells degraded caffeine completely in 36 h. Sucrose in the medium did not affect caffeine degradation and remain unconsumed by the bacteria. Under optimal cell loading of 10 × 1011 CFU/L, complete degradation of caffeine was achieved in 2 h. Traces of theaflavin and thearubigin were degraded, whereas other polyphenols remain unaffected and were monitored by UV-visible spectrophotometer. Induced cells also displayed the ability of simultaneous degradation of theobromine present in wastewater. Results showed that caffeine degradation is unaffected at adverse pH, indicating its effectiveness in industrial waste treatment where complete reduction of caffeine and its metabolite theobromine can be achieved by induced cells.