Rice University has announced that they have a new process for the glycerin that remains when bio oils are made into biodiesel. About 10% of bio oil products in making biodiesel is glycerin, the stuff you might have used to soften hands and such. Not long ago industries that used glycerin were buying the stuff, but lately with the surge in biodiesel, there is such a glut that biodiesel producers are paying to get it off their hands.

The paper about this is available online in the journal Metabolic Engineering. This paper and others from earlier in the year describe a fermentation process that allows E. coli and other enteric bacteria to convert glycerin into formate and succinate plus some other valuable organic acids. These products are much more valuable than the ethanol process announced a year ago.

The break through comes from cracking the idea that only organisms that could ferment glycerin were capable of producing a chemical called 1,3-propanediol or 1,3-PDO. But the two workhorses of biotechnology, E. coli and the yeast Saccharomyces wouldn’t produce the 1,3-PDO in glycerin.

Rice University Team Led By Gonzalez

So the team led by Ramon Gonzalez, the Rice University William W. Akers Assistant Professor in Chemical and Biomolecular Engineering set out to uncover new metabolic pathways for the E. coli bacteria. The result is a process that not only modifies the bacteria into a new form of productivity, but the production is much higher value added than going straight to ethanol.

Once the new pathways were identified the team began using their metabolic engineering skills to design new versions of E. coli. Your standard E. coli will ferment glycerin but yield very little valuable succinate. The team’s pathway modification and process development of a new set of fermentation conditions have increased the succinate output by 100 fold. Gonzalez said. “It wasn’t easy to zero in on these conditions, so it wasn’t the sort of process that someone would stumble upon by accident.”

With 2007 yielding some 450 million gallons of biodiesel, 60 new plants to come on line through 2010 with another 1.2 billion gallons the prospect of 180 million gallons of glycerin on the market could be a problem.

Gonzales goes on to suggest that while the fermentation of glycerin to ethanol is highly efficient, the product isn’t at the price range of the specialty chemicals. Those things like formate and succinate are for now, enjoying a high price as the current sources are made from petroleum. Succinate is a high-demand chemical feedstock that’s used to make everything from non-corrosive airport deicers and nontoxic solvents to plastics, drugs and food additives.

This work is already licensed to one of the funding supporters, Glycos Biotechnologies, Inc. who plans a demonstration facility to be up in the next 12 months.

There, not much left from those bio oil products now!


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