A team of researchers led by University of California, Riverside (UCR) Professor of Chemical Engineering Wilfred Chen has constructed for the first time a synthetic cellulosome in yeast, which is much more ethanol-tolerant than the bacteria in which these structures are normally found.
The yeast cellulosome could enable efficient one-step “consolidated bioprocessing” by maximizing the catalytic efficiency of cellulosic hydrolysis with simultaneous fermentation. The process of using these engineered yeasts can potentially make the production of bioethanol from biomass more efficient and economical.
The federal Energy Policy Act mandates the increased production of renewable fuel, such as bioethanol created from biomass. Currently, the most common method of producing bioethanol uses sugar cane and corn starch. Efficient, cost-effective methods of using non-food related materials like cellulosic biomass found in agricultural and wood-pulping wastes is the focus of new research by Chen’s team, among others.
The use of multiple enzymes in the cellulosome greatly increases the efficiency of hydrolysis because heterogeneous forms of cellulose can be digested. The artificial cellulosome developed at UCR is highly modular and can be engineered to display ten or more different cellulases, the composition of which can be tuned to optimized hydrolysis of any feedstock.
Cellulosomes are self-assembled structures found on the exterior of certain bacteria that allow the organisms to efficiently break down cellulose. The cellulosome contains multiple types of cellulases (enzymes that break down cellulose), optimally spaced for maximum activity.
The experimental cellulosome contains three different cellulases. Yeast engineered with this triple cellulase cellulosome was able to multiply to high levels with cellulose as the only carbon source. Compared to controls engineered with one or two cellulases, the triple cellulase displaying yeast had higher rates of hydrolysis, demonstrating the benefit of using diverse cellulytic enzymes in a single organism.
The process is described in the paper “Functional Assembly of Minicellulosomes on the Saccharomyces cerevisiae Cell Surface for Cellulose Hydrolysis and Ethanol Production,” in the October 1, 2009, issue of the American Society of Microbiology’s journal Applied and Environmental Microbiology. The paper was co-authored by UCR students Shen-Long Tsai and Shailendra Singh, post-doctoral researcher Jeongseok Oh, and Ruizhen Chen, associate professor at the School of Chemical and Biomolecular Engineering at Georgia Institute of Technology.
Ongoing synthetic yeast cellulosome research being done at UCR is funded in part by grants from the National Science Foundation and the Department of Energy. University of California is looking for industry partners interested in evaluating this method of ethanol production. For more information please contact Michael Arciero at email@example.com (UC reference number 2009-328).
Don Davidson | EurekAlert!
Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory
Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine