If the biofuel known as bioethanol is to make a major contribution to our fuel supplies, then we may well require the assistance of some tiny insect helpers, says Michael Scharf, an assistant professor of entomology at the University of Florida, Gainesville.
In a review to be published in Biofuels, Bioproducts & Biorefining, Scharf and his colleague Aurlien 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 han
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