Scientists Study the Potential of Aquatic Wood Borer for Biofuel Production

An international collaboration of scientists has determined the structure and function of a key enzyme used by tiny marine wood borers to break down wood. The findings, published in PNAS, suggest that the unique and robust enzyme offers a potential for producing biofuels from woody biomass.

The researchers studied the enzyme that gives the wood-boring crustacean Limnoria quadripunctata the special ability to thrive on a diet of wood. It has been known that Limnoria have a digestive system free of microbial populations but secrete a class of enzymes that can degrade lignocellulose into simple sugars, which is a key step in bioethanol production.

Using advanced biochemical analysis and X-ray imaging techniques, the Limnoria enzyme, designated as LqCel7B, was found to be a unique cellulase secreted into the gut of the crustacean to function for wood degradation. Detailed characterization also resolved that LqCel7B contains an acidic surface and has the ability to remain stable and active at high salt concentration, making it a candidate enzyme that works under aggressive chemical conditions.

The robust nature of the enzyme makes it compatible for use in conjunction with sea water, which would lower the costs of processing. Lowering the cost of enzymatic processes is critical for making the production of lignocellulosic biofuels cost effective. The robust characteristic would also give the enzyme a longer working life and allow it to be recovered and re-used during processing.