Researchers have discovered that a marine wood borer (limnoria quadripunctata) has biological properties that could be useful to the biomass energy and biofuels production industries.
Researchers from the United Kingdom, the Energy Department's National Renewable Energy Laboratory (NREL), and the University of Kentucky published a paper describing a novel cellulose-degrading enzyme produced by the wood borer, commonly known as the gribble.
Gribbles are biologically intriguing because they exhibit the ability to produce their own enzymes instead of using symbiotic microbes to break down the biomass they eat. New biomass-degrading enzymes from novel sources such as the gribble may prove beneficial to the biofuels industry.
Gribbles are 1-3 millimeters in length, but collectively they bore through wood quickly, and are responsible for natural and man-made marine timber damage around the world. Scientists at Universities of Portsmouth and York in the U.K. and the University of Kentucky in the U.S., with researchers from NREL, are hoping to turn that special talent into a source of novel enzymes for the biofuels industry.
Gribbles live in inter-tidal zones and, similar to termites, they burrow into wood. Gribbles, unlike termites or many other animals including people, do not rely on gut bacteria to make enzymes to aid their digestion. Gribbles instead exhibit a sterile gut, and secrete their own enzymes into their guts made in a special organ termed the heptopancreas that runs the entire length of their body.
Interestingly, several of the enzymes produced by gribbles are in the same important enzyme classes that are typically harvested from fungi in the biosphere for industrially deconstructing the cellulose in biomass. The gribble enzymes hold promise of tolerating salts much better, likely due to the fact they evolved in a marine environment.
This adaptation may have beneficial implications for the ability of the gribble enzymes to more efficiently operate in a high-solids, industrial environment, breaking biomass down more effectively into sugars, which can then be converted into ethanol or a hydrocarbon fuel to replace gasoline, diesel or jet fuel.
NREL ran computer simulations and aided in the structural and biochemical analysis of the enzyme.
The work leading to the paper provided deeper understanding of how the organism adapts and survives. NREL and UK scientists are now examining how features of the gribble enzymes could be incorporated into industrially relevant enzymes and settings.
NREL is the U.S. Department of Energy's primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for DOE by the Alliance for Sustainable Energy LLC.