Cellulose Enzymes from the Termite Gut
A metagenomic study of the microbes that live in wood-eating termites could suggest new ways to make cellulosic ethanol

Source: “Metagenomic and Functional Analysis of Hindgut Microbiota of a Wood-Feeding Higher Termite”
Jared R. Leadbetter et al.
Nature 450: 560-565

Results: In a massive genomic study of the microbes living within the termite gut, scientists may have identified close to a thousand enzymes that break down wood.

Why it matters: Biofuels made from cellulosic biomass, including cornstalks, perennial grasses, and wood chips, could provide a cheaper and more environmentally beneficial alternative to corn-derived ethanol. However, breaking down cellulose into simple sugars that can be fermented into ethanol is a complex, inefficient, and expensive process. The newly identified cellulose-digesting proteins could shed light on termites’ wood-eating capacity and suggest cheaper, more efficient enzymes for generating cellulosic ethanol.

Methods: Scientists collected Nasutitermes termites from Costa Rica and isolated DNA from the microbes living in part of the insects’ gut. They then sequenced and analyzed the genomic material from the many different types of bacteria, searching for particular sequences known
from other studies to be
linked to the ­ability to break down cellulose.

Next steps: Researchers are now testing some of the newly identified microbial enzymes for their wood-digesting ­ability, as well as searching for combinations of different enzymes that work together synergistically.