Real Time Respiration Measurements

Many methods for measuring aerobic respiration, including electrodes and colorimetric assays, limit the capacity for obtaining replicate measurements or the ability to detect oxygen consumption in real time. The OxoDish® - a microtiter plate with integrated oxygen sensors - and SDR SensorDish® Reader offer the potential for making twenty four simultaneous respiration measurements in real time, benefitting ecologists measuring the respiration of complex microbial communities.

Our aim was to optimize the SDR OxoDish® system for measuring the rate of oxygen (O₂) consumption of pure cultures of bacteria and in soil slurries of complex microbial communities. Soil slurries are particularly challenging due to the potential for physical settling of soil particles on the optode. Two modifications of the OxoDish® were needed to measure O₂ consumption accurately for these samples: minimizing O₂ influx into the wells of the microtiter plate and maintaining a well-mixed solution so that O₂ consumption was homogeneous throughout the depth of the well. A pure culture of Pseudomonas strain HF3 and forest soil were used to test modifications to the OxoDish®.