In California, Lawrence Berkeley Lab has developed a new technology that enables the engineering of host microorganisms suitable for biofuel processing using ionic liquid pretreatment. It may also enable fermentation under septic conditions, since invasive organisms are unlikely to tolerate ionic liquid residuals at the concentrations tolerated by the JBEI host.
Since ionic liquid can be toxic to microbes, such as E. coli, used in downstream biofuel processing steps, current methods using ionic liquid pretreatment require the ionic liquids to be thoroughly washed out of the hydrolysate before microbes are added. Relaxing the requirement to remove ionic liquids between the pretreatment and biofuel production stages improves the cost effectiveness of ionic liquid pretreatment, which is noted for its improved sugar recovery.
Laboratory tests indicated that an engineered strain of E. coli carrying the IL-tolerance genes was able to grow and produce the fuel precursor, bisabolene, in the presence of 4% 1-ethyl-3-methylimidazolium chloride, a concentration that completely inhibited the standard E. coli biofuel host.
More background on the story from the Digest
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