Recent advances in the microbial production and recovery of apolar molecules.

Several apolar molecules of interest for the production of fuels and chemicals can nowadays be produced by fermentation. Those secreted from the microbial cell are of particular interest for large scale bioprocessing, since they allow for cell reuse, in situ product recovery and competitive production levels. So far, however, bioprocess strategies for fermentation and product recovery have been developed for addressing needs at the laboratory scale, rather than the process scale. Most commonly used strategies include extractive fermentations, product stripping in the gas phase, and off-line de-emulsification followed by intensive centrifugation. At the same time, current techno-economic studies at process scale have demonstrated the absolute need for significant improvements in both microorganism and process technology, for these processes to become competitive.