(139f) Rhodobacter As a Platform for Autotrophic Fuel Production

Chemolithoautotrophic growth (growth on H₂, O₂ and CO₂) is difficult because of two major issues. One is safety – the mixture of H2 and O2 is explosive over the useful range of concentration. The second is gas-liquid mass transfer. Since >90% of the nutrients needed by the cells come from the gas phase, they need to be transferred to the liquid phase at a very high rate to match the rate at which they are consumed by growing cells. For these reasons literature data on the kinetic parameters of autotrophic organisms are scarce. We have tried to design a device that could be used with too much difficulty to measure the important parameters such as growth rate and yields on different gases for an autotrophic organism.

There are three parts to the autotrophic growth device aka “autotrophinator”, which carry out three distinct functions – measuring growth kinetics (LED cell), delivering autotrophic gas mixture safely (electrolysis) and achieving very high mass transfers to remove that limitation on growth (solenoid-bobber system). Data acquisition systems can collect Optical Density (OD), pressure and electrolysis current data for calculation of kinetic parameters.