With increasing demands for sustainable energy, being able to cost-efficiently produce biofuels from plant biomass is more important than ever. However, lignin and hemicelluloses present in certain plants mean that they cannot be easily converted into biofuels. A study published in BioMed Central's open access journal Biotechnology for Biofuels appears to have solved this problem, using gene manipulation techniques to engineer plants that can be more easily broken down into biofuels.
Plants high in lignin and hemicelluloses – lignocellulosic biomass – have a high content of pentose sugars that are more difficult to ferment into fuels than plants with hexose sugars. In order to be useful for biofuel production, scientists need to be able to engineer plants with smaller amounts of xylan – the major non-cellulosic polysaccharide – present in secondary cell walls.
With this in mind, a research group from the Lawrence Berkeley National Laboratory, USA, used 3 mutant strains of Arabidopsis deficient in xylan – irregular xylem (irx) mutants irx7, irx8 and irx9 – in order to engineer plants with low xylan content and improved properties for easier breakdown of carbohydrate into simple sugars (saccharification). The irx mutants normally exhibit severe dwarf phenotypes that result from xylem vessel collapse and consequent impaired transport of water and nutrients. The team hypothesized that restoring xylan biosynthesis in the plants would complement the mutations.
To reintroduce xylan biosynthesis into the xylem of irx7, 8 and 9, Henrik Scheller and colleagues manipulated the promoter regions of vessel-specific VND6 and VND7 transcription factor genes. Significantly, they found that the ensuing phenotypes completely restored wild-type growth patterns in some cases, resulting in stronger plants with restored mechanical properties, whilst at the same time maintaining a low overall xylan content and improved saccharification properties that allowed for better breakdown into biofuels.
Plants with up to 23% reduction in xylose levels and 18% reduction in lignin content were obtained, whilst normal xylem function was restored. The plants also showed a 42% increase in saccharification yield after pretreatment.
Lead author Scheller said, "These results show that it is possible to obtain plants that have reduced amounts of xylan in their walls while still preserving the structural integrity of the xylem vessels. The xylan engineering system we present here is a great step towards tailored bioenergy crops that can be easily converted into biofuels. He continued, "This approach in Arabidopsis has the potential to be transferred to other biofuel crop species in the near future, in particular, the poplar species."
These results from this study provide hope that a viable alternative to fossil fuels may soon be available.
Engineering of plants with improved properties as biofuels feedstocks by vessel-specific complementation of xylan biosynthesis mutants Pia D Petersen, Jane Lau, Berit Ebert, Fan Yang, Yves Verhertbruggen, Jin S Kim, Patanjali Varanasi, Anongpat Suttangkakul, Manfred Auer, Dominique Loque and Henrik V Scheller Biotechnology for Biofuels
BioMed Central: http://www.biomedcentral.com
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
All plants contain toxins which continue to work after leaf fall, so how worms are able to stomach dead grass and leaf litter has long been a mystery
One of the oldest-known complex organisms had a surprising complicated sex life, scientists report.
A study finds that wild bonobos use a single high-pitched call in a variety of contexts, showing a linguistic flexibility that was thought to be uniquely human.
Researchers at the Woods Hole Oceanographic Institute in Cape Cod have begun using a helicopter-style drone to monitor humpback whales off the coast, collecting breath samples from their blowholes and taking aerial pictures.
His moves are intended to woo females, but they seem to work on humans, too
A new Bic commercial claims four benefits to writing by hand.
Foraging bumblebees can pick up nearly half their weight in pollen before heading home to the hive, research shows. All that weight tucked into hollows on their hind legs can complicate flying.
Scientists are working on ways to train our brains away from deeply held prejudices — including hacking your subconscious while you sleep.
A species of clownfish has been shown to grow bigger in warmer conditions, suggesting that some animals may benefit from global warming
The first ever trial of reprogrammed stem cells is put on hold while scientists investigate whether the procedure caused a potentially cancerous mutation