Have you ever seen a burning bush? These shrubs originated in Asia but have managed to invade North America. They're so-called because in the Autumn they have distinctive flame-red leaves. They look impressive, but are actually considered a bit of a pest, as they're an invasive species. But researchers at Michigan State University have made a discovery that could help turn the burning bush into the saviour of future biofuels, according to their paper in PNAS this week.
The burning bush produces an unusual oil, which could be very useful for fuel and food as it has quite a low viscosity – stickiness or thickness. Many plant oils are too thick to use in diesel engines, so they have to undergo a process to convert them to biodiesel. The oil from the burning bush is runny enough to use directly in diesel engines. And it's also lower in calories than other plant oils, so it might be useful for making low-cal foods. But unfortunately, burning bush plants aren't really suitable for agricultural growing and harvesting. So the researchers, led by WHO, sequenced the genes in a common ornamental species of burning bush, to find the gene that produces the key components of the oil – molecules called acetyl glycerides.
The scientists took the gene and used genetic engineering to add it to a plant called Arabidopsis – a type of cress commonly used by plant researchers. The modified plants then started making acetyl glycerides, producing oil with a purity up to 80%. So it's quite promising that they'll be able to produce high-quality oil on a large scale in the future, either by genetically modifying oil-seed crops such as oil-seed rape (known as canola in the US), or in other, more technological biological biofuel production systems, such as algae. They're not there yet, but these are exciting early results that will help to fuel further research, if you pardon the pun.