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 firstname.lastname@example.org (UC reference number 2009-328).
Don Davidson | EurekAlert!
Modern genetic sequencing tools give clearer picture of how corals are related
17.08.2017 | University of Washington
The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Physics and Astronomy
17.08.2017 | Materials Sciences
17.08.2017 | Materials Sciences