Fungi Make Biodiesel Efficiently At Room Temperature

Scientists at the Indian Institute of Chemical Technology have found a much better way to make biodiesel. Their new method could lower the cost and increase the energy efficiency of fuel production.

Instead of mixing the ingredients and heating them for hours, the chemical engineers pass sunflower oil and methanol through a bed of pellets made from fungal spores. An enzyme produced by the fungus does the work -- making biodiesel with impressive efficiency.

Last Monday, Ravichandra Potumarthi showed off his work during a poster session last Monday at the International Conference on Bioengineering and Nanotechnology. After returning to his lab in Hyderabad, he was able to send out some pictures of his experimental reactor (shown on right) and the fungal pellets.

Typically, biodiesel is made by mixing methanol with lye and vegetable oil and then heating the brew for several hours. This links the methanol to the oils to produce energetic called esters. Unfortunately, heating the mixture is a huge waste of energy, and a major selling point of alternative fuels is efficiency. An enzyme called lipase can link link oil to methanol without any extra heating, but the pure protein is expensive.

Potumarthi has a simple solution. Why bother purifying the lipase? It would be easier to just find an organism that produces plenty of the enzyme and squish it into pellets. In this case, the fungus Metarhizium anisopliae does the trick.

Wired Science, August 20, 2007