Researchers from the USA and China reported in the open-access journal PLoS Genetics the results of their study comparing the genetics and metabolic capabilities of microbes residing in the intestinal tracts of grasshoppers, termites, and cutworm. These insects represent three distinct orders and consume different food types.

The study revealed remarkable diversity of microbes living in the insects' guts and a strong correlation between the plant-digesting capabilities of the gut microbes and their hosts' diet. It showed further that grasshoppers harbor efficient cellulose-digesting enzymes that can be tapped for biofuel applications. According to the researchers, the characteristic adaptation to diet changes shown by the gut microbes may be exploited in designing new biotechnological approaches for breaking down the tough molecules involved in bioenergy conversion such as cellulose and lignin.

A study led by researchers from the Department of Life Sciences at Imperial College, London found that natural genetic variations in willow's ability to form modified wood called reaction wood could explain why some strains of willow produce more biofuels than others.

Known as a physiological response by woody plants to counteract external stresses like strong wind, reaction wood or RW formation creates an excess of sugar molecules in the willow's stems to straighten the plant upwards. The high energy sugars released from the enzymatic breakdown of RW can be fermented into biofuels.  Results of the study published in the journal Biotechnology for Biofuels show that the RW response trait is responsible for the differences observed in willows with respect to sugar yield from enzymatic breakdown of stem biomass. When RW formation was induced in pot-grown trees by bending their stems, sugar yield from enzymatic breakdown was strongly correlated with that for mature field-grown trees. Field studies further revealed a five-fold increase in sugar yield from a willow variety exposed to windy condition when compared with the same variety grown in more sheltered condition. The researchers concluded that further work on RW response trait will be useful in breeding and genetic modification of willows and other woody crops for improved biofuel feedstocks.

A study published in the journal Nature reveals the potential of so-called marginal lands or lands unsuited for food crops in ten Midwestern US states for growing mixed species of cellulosic biofuel crops that can produce up to 21 billion liters of ethanol with less greenhouse gas emission. Led by Michigan State University researchers, the study was based on a comparative assessment of six alternative cropping systems over 20 years and the use of a computer model for successional vegetation on marginal lands within 80 kilometers of a potential biorefinery.

Results suggest that such vegetation could produce 21 billion liters of cellulosic ethanol per year from roughly 11 million hectares of currently idle lands. This potential production represents about 25 percent of the 2022 target for cellulosic biofuel set by the US government without initial carbon debt and indirect land-use costs which are associated with food-based biofuels.