A microbial biosensing system for monitoring methane

A microbial biosensing system for the measurement of methane has been developed using an immobilized mixed culture of Pseudomonas aeruginosa and Klebsiella sp. together with a dissolved oxygen (O2) sensor. When methane was applied to the biosensing system, the dissolved O2 content decreased until a steady-state was reached. The biosensing system response depends linearly on methane concentration between 1.0 and 5.0% (v/v) with a detection limit of 0.3% (v/v) (S/N = 3) and a 100-s response time. Phosphate buffer (pH 7.0, 25 mM) and room temperature (20–25 °C) were chosen as the optimum working conditions. Some parameters including pH, temperature, operational and storage stability were studied in detail for characterization of the biosensing system.