Biofuels’ 10 scariest challenges: Part 1 of 2

6. Lignin

“You can make almost anything out of lignin,” goes the old biotech joke, “except money.” A huge percentage of terrestrial biomass is in the form of lignin, the substance that gives plants their igidity — and it’s been near-impossible to break down, to date.

“The main bottleneck is the pretreatment,” Wout Boerjan told Scirntific American this week, referring to the expensive process of cooking or otherwise softening the plant material so the sugars can be extracted and converted. “[The industry] wants to make their products in an inexpensive way.”

The search for ways around lignin have led researchers to non-terrestrial plants like kelp that don’t contain lignin, as well as wood-feasting microbial Vikings like Gribbles that bring all their own tools for breaking down wood into food.

It’s a microscopic worm that causes wood rot, at sea, for piers, jetties and rowboats. But the gribble has huge fans in the world of bioprocessing. The gribble’s trick? Doing all that conversion with its own, native, genetically-endowed portfolio of enzymes — and apparently, no help required from a fantastically complex team of gut-inhabiting, fellow-traveling microbes.

Elsewhere in the world of microbes, a group of researchers led by the University of Georgia’s Mike Adams have found another thermophilic bacterium with amazing properties — this time, finding a bacterium that can, without pretreatment, break down biomass, including lignin, and release sugars for biofuels and chemicals production.

This week, a Belgian research team is reporting the discovery of a way to shut off Caffeoyl shikimate esterase (CSE) , which assists in the formation of lignin — and the shutdown has resulted in up to 36% less lignin formation in the model plant Arabidopsis thaliana. More on that here.

In tomorrow’s Digest: Biofuels 10 scariest challenges: Part 2 of 2 – here.