The purpose of this experiment is to determine the long term characteristics of the growth of our Nir transformant anaerobically. Specifically, we measure nitrous oxide production over a period of 10 hours.

The experiment was performed on September 17th.


Protocol Bioreactor

For reasons that are not understood, the experiment became aerobic in each chamber just after 12:00, and the lab technician began sparging the reactors at a low rate to keep the reaction anaerobic.

Experiment timeline

  • 10:00 Set up experiment; begin sparging with nitrogen to make the medium anaerobic
  • 11:00 End sparging
  • 14:00 Take first sample
  • 22:00 Take last sample
This image shows the bioreactor set up to run in triplicate.


Nitrous oxide concentrations measured in the bioreactor at the beginning (t=14:00) and end (t=22:00) of the experiment.

Time [N2O] Replicate 1 [N2O] Replicate 2 [N2O] Replicate 3 [[N2O] Distilled Water Control
14:00 1.84 mg/L 1.64 mg/L 1.60 mg/L N/A
22:00 1.43 mg/L 1.44 mg/L 1.50 mg/L 1.65 mg/L


The concentrations of nitrous oxide were slightly higher at the beginning of the experiment compared to the end, but none of the readings showed a large deviation from the control reading. Since the chambers were sparged with nitrogen, any nitrous oxide we would have produced would have been sparged off as well. Ideally, we would repeat this experiment to have an instance that did not become aerobic, but we did not have time to complete this work prior to the wiki freeze.