This post from GreenCarCongress.com says Spanish researchers Gemma Vicente and colleagues made the discovery that could open up many more feedstocks for biodiesel … but admit the process needs some work:
Oils from oleaginous microorganisms, such as yeasts, fungi, bacteria, and microalgae, are under investigation as alternatives to plant—and especially food crop—oils as feedstocks for renewable fuels and chemicals. Algae are especially of interest because of their ability to capture CO2 in lipids, but cost-effective, large scale production is still problematic, note Vicente et al. in their paper. Furthermore, not all oleaginous microorganisms have ideal lipid profiles for biodiesel production.
On the other hand, lipid profiles could be modified by genetic engineering in some oleaginous microorganisms, such as the fungus Mucor circinelloides, which has powerful genetic tools. We show here that the biomass from submerged cultures of the oleaginous fungus M. circinelloides can be used to produce biodiesel by acid-catalyzed direct transformation, without previous extraction of the lipids. Direct transformation, which should mean a cost savings for biodiesel production, increased lipid extraction and demonstrated that structural lipids, in addition to energy storage lipids, can be transformed into FAMEs.
—Vicente et al.
It’ll be interesting to see how long it will take before this technique is available on a commercial basis. Stay tuned.