Bisabolane as a Biosynthetic Alternative to Diesel

Researchers from the US Department of Energy (DOE) Joint BioEnergy Institute (JBEI) recently identified bisabolane as a plausible biofuel alternative to fossil-fuel-based Number2 (D2) diesel. Bisabolane is an organic compound belonging to a class of compounds called terpenes. Terpenes are usually found in plants and are conventionally used as fragrances or flavorings. The JBEI scientists also reported that they have engineered a bacterial strain (Escherichia coli) and a yeast strain (Saccharomyces cerevisiae), which can produce its precursor, bisabolene. Bisabolene can then be easily hydrogenated to produce bisabolane.

Bisabolane is reported to have a similar chemical structure to diesel (i.e. bisobolane has a carbon length of C15 while diesel has an average carbon length of C16). The researchers also found that it has better fuel properties in terms of freezing point and cloud point. These better fuel properties were attributed to the compound's branched and cyclic chemical structure. After identifying bisobolane as a feasible diesel alternative, the researchers then developed a method for producing the diesel alternative. In their method, they genetically engineered the above-mentioned bacterial and yeast strains to perform a mevalonate pathway that will produce bisabolene (bisabolane's precursor). However,the researchers are still currently trying to improve the process by genetically engineering the cells to directly produce bisobolane, instead of bisobolene. The price of bisabolane is estimated at $6 per gallon, which is still more expensive than diesel. However,due its superior properties and renewable nature, it drives researchers to further investigate and improve this new alternative. The full paper is published in the journal, Nature Communications (URL above).

Related chemical information about bisabolane: http://www.chemspider.com/Chemical-Structure.453984.html.