Today marks the closure of the 31st Symposium of Biotechnology for Fuels and Chemicals in San Francisco after topics were covered including plant, enzyme and microbial science technology to biomass pre-treatment as well as bio-refinery deployment and sustainability issues.
Much of the event focused on optimising different aspects of cellulosic ethanol production and among the papers presented were several describing potential new engineered genetic pathways to produce biobutanol.
Biobutanol is attracting interest as it has a higher energy content compared to ethanol and can be transported in existing pipelines. It also has the ability to blend at higher ratios meaning less impact on engine performance. However, commercial biobutanol production is limited by low values for the final product concentration; and degradation stemming from the toxicity of butanol to organisms.
As such, researchers are looking to tackle a way to enable yeast to ferment the pentose sugars that derived from cellulosic biomass. A speaker from the Goethe Universtat Frankfurt am Main described the cloning and successful expression of xylose isomerise with high activity in the industrial yeast Saccharomyces cerevisiae which enables the yeast to ferment sugars.
Though the initial output is targeted to be ethanol Dr Eckhard Boles from the university said they were considering a butanol pathway as well and have already engineered yeast that delivers butanol.
