Engineered Yeast Makes More Biofuels
by Helen Tunnicliffe (TCE Today) Moving process to mitochondria ups production 260%
Chemical engineers at Massachusetts Institute of Technology have engineered yeast to increase production of isobutanol, a promising biofuel, by 260%.
Isobutanol, a heavy alcohol, contains more energy than ethanol and is more compatible with existing fuel transport networks. Yeast makes small amounts of isobutanol during fermentation, but traditionally, efforts have been made to suppress its formation as it spoils the flavour of wine, but now chemical engineering professor Gregory Stephanopoulos and biology professor Gerald Fink are working together the change that.
…The team engineered the enzymes for isobutanol production so that they each had a protein tag identifying them to the yeast cell as belonging within the mitochondria. This meant that the entire isobutanol production process was confined to the mitochondria.
Exactly why this approach boosts isobutanol production quite so much isn’t clear, but the researchers have two theories. The first is that clustering the enzymes together in a small space makes it more likely that the reactions will occur, although this is difficult to prove, according to researcher Jose Avalos. The second theory is that it makes it easier for the isobutanol enzymes to convert the intermediates before they are used in another pathway. READ MORE and MORE (Renewable Energy World) Abstract