In a review to be published in Biofuels, Bioproducts & Biorefining, Scharf and his colleague Aurélien Tartar describe how the enzymes produced by both termites and the micro-organisms that inhabit their gut – known as symbionts – could help to produce ethanol from non-edible plant material such as straw and wood.
“Through millions and millions of years of evolution, termites and their symbionts have acquired highly specialised enzymes that work together to efficiently convert wood and other plant materials into simple sugars,” says Scharf. “These enzymes are of the most value to bioethanol production.”
Current bioethanol production processes tend to use edible plant materials, such as starch from corn (maize) and sugar from sugar cane, which contain easily accessible sugar molecules that can be fermented to produce ethanol. However, using food crops to produce ethanol has proved highly controversial, with bioethanol being blamed for much of the recent rises in food prices.
The non-edible parts of many plants also contain a large number of sugar molecules, which could potentially be used to produce ethanol. But the problem is that these sugar molecules are far less accessible. This is because they’re locked up within a substance known as lignocellulose, which provides structural support for plant cell walls.
Breaking this substance up into its component sugar molecules is far from easy. One approach involves pretreating the lignocellulose by heating it in combination with acids or bases and then exposing the pretreated material to various enzymes. Another approach is very fine grinding followed by enzymatic treatment.
Termites, on the other hand, don’t seem to have too much trouble digesting wood and other lignocellulosic materials into their component sugars, as many homeowners can attest. The termite appears to favour the fine grinding approach in combination with its own unique set of enzymes. These enzymes are secreted by both termites and the symbionts that colonise their gut, and act on the lignocellulose that has been chewed to very small particle sizes by the termite.
Despite the small size of the termite gut and the difficulty in analysing its contents, a few research groups have attempted to study what Scharf and Tartar call the termite digestome. This is the pool of genes, both termite and symbiont, that code for the enzymes that break down and digest lignocellulosic material.
Using a variety of genomic and proteomic techniques, these groups have managed to identify a number of the main enzymes, many of which could prove useful for producing ethanol. This work has already provided strong preliminary evidence that the enzymes produced by the termites and their symbionts tend to work collaboratively, with the lignocellulosic material having to be partially digested by termite enzymes before it can be further digested by symbiont enzymes.
But the study of the termite digestome has really only just begun. “There are many directions that the science can now head,” says Scharf. “First, we now have the ability to produce and test individual enzymes for their competency and roles in lignocellulose degradation. Once we identify major players (from termites and symbionts), we can test combinations that may have applications in making bioethanol production more feasible from existing feedstocks, and maybe even other feedstocks that aren't on our radar screens yet.”
This kind of digestome analysis could also be applied to other insects that feed on woody material, such as wood-boring beetles, and certain wasps and flies, Scharf adds.
Light green plants save nitrogen without sacrificing photosynthetic efficiency
21.11.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
Filling intercropping info gap
16.11.2017 | American Society of Agronomy
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
23.11.2017 | Information Technology
23.11.2017 | Physics and Astronomy
23.11.2017 | Life Sciences