Power Your Car on Sugar – Renewable Crude Oil from Yeast

A new strain of genetically-modified yeast cells fermented in a novel environment could change the industrial-scale production of renewable biofuels. This fully renewable energy source, with low carbon emissions, appears at first glance to be the ideal solution to our fossil fuels fix. The one drawback – biofuels are notoriously difficult to make. Researchers at Austin University, Texas, spent four years tinkering with genes in the yeast Yarrowia lipolytica developing it.

New genetically souped-up yeast cells are making more lipids (fat) than ever before. And they run on sugar.  90% of the cell body weight is stored fat in this system. That’s an amazing 60 fold increase on the natural fat levels of this species. The researchers genetically modified the yeast cells to delete or over-express lipid-production genes.

Yeast cells are cultured with sugar in huge vats known as fermenters. Lipids – one of the key metabolic products of sugar fermentation – are then extracted from the fermenter and used to make several different agents, including “sweet crude”. This energy-dense alternative to petrol can be used to power your car. Many other petroleum-derived products like nylon could also be made using yeast lipids.

In most yeast fermenters the only way to induce the yeast cells to store the lipids they make is by starving them of nitrogen. The researchers in this study succeeded in “starving” cells through genetic means, making the process cheaper and more commercially viable.

Fermentation is a really key area in biofuel production. Yeast fermenters are compact, mobile and rely on a biological cell type which is highly manipulable from a genetic perspective. This new study further highlights the advantages of yeast over alternative low-yield biofuel crops such as soybean, which take up vast swathes of land better suited to food crops.

To access the original study, please follow this link:

http://www.nature.com/ncomms/2014/140120/ncomms4131/full/ncomms4131.html