A study of methanol transport/uptake by a methanol‐utilizing bacterium L3 in a batch bioreactor

Two novel, nitrogen‐limited and oxygen‐limited, perturbed transient experiments were performed to examine the presence of active transport of methanol and study the effect on methanol uptake by a methanol‐utilizing bacterium, L3 , in a batch bioreactor. Transient limitations of both ammonium ions and O 2 in batch cultures were found to cause methanol leakages out of the cells, suggesting the presence of an active transport of methanol in L3 . Such experimental results were used to indirectly estimate the intracellular levels of methanol during a batch growth of L3 . The results of our analysis indicate that the intracellular methanol level is high and show an increasing trend during the unbalanced phase, but falls to a constant low level in the balanced phase of a typical batch growth 8 of L3 . A simple modelling analysis suggests that a four‐parameter “pump‐and‐extrusion” model could be used to adequately describe the transport of methanol between the extra cellular and intracellular phases of batch cultures of L3 .