Engineered Yeast Speeds Ethanol Production

MIT scientists have engineered yeast that can improve the speed and efficiency of ethanol production, a key component to making biofuels a significant part of the U.S. energy supply.

Currently used as a fuel additive to improve gasoline combustibility, ethanol is often touted as a potential solution to the growing oil-driven energy crisis. But there are significant obstacles to producing ethanol: One is that high ethanol levels are toxic to the yeast that ferments corn and other plant material into ethanol.

By manipulating the yeast genome, the researchers have engineered a new strain of yeast that can tolerate elevated levels of both ethanol and glucose, while producing ethanol faster than un-engineered yeast.

Fuels such as E85, which is 85 percent ethanol, are becoming common in states where corn is plentiful; however, their use is mainly confined to the Midwest because corn supplies are limited and ethanol production technology is not yet efficient enough.

Boosting efficiency has been an elusive goal, but the MIT researchers, led by Hal Alper, a postdoctoral associate in the laboratories of Professor Gregory Stephanopoulos of chemical engineering and Professor Gerald Fink of the Whitehead Institute, took a new approach.

The key to the MIT strategy is manipulating the genes encoding proteins responsible for regulating gene transcription and, in turn, controlling the repertoire of genes expressed in a particular cell. These types of transcription factors bind to DNA and turn genes on or off, essentially controlling what traits a cell expresses.

The traditional way to genetically alter a trait, or phenotype, of an organism is to alter the expression of genes that affect the phenotype. But for traits influenced by many genes, it is difficult to change the phenotype by altering each of those genes, one at a time.

Targeting the transcription factors instead can be a more efficient way to produce desirable traits. "It is the makeup of the transcripts that determines how a cell is going to behave and this is controlled by the transcription factors in the cell," according to Stephanopoulos, a co-author on the paper.

The MIT researchers are the first to use this new approach, which is akin to altering the central processor of a computer (transcription factors) rather than individual software applications (genes), says Fink, an MIT professor of biology and a co-author on the paper.

In this case, the researchers targeted two different transcription factors. They got their best results with a factor known as a TATA-binding protein, which when altered in three specific locations caused the over-expression of at least a dozen genes, all of which were found to be necessary to elicit an improved ethanol tolerance, thus allowing that strain of yeast to survive high ethanol concentrations.

Because so many genes are involved, engineering high ethanol tolerance by the traditional method of over-expressing individual genes would have been impossible, says Alper. Furthermore, the identification of the complete set of such genes would have been a very difficult task, Stephanopoulos adds.

The high-ethanol-tolerance yeast also proved to be more rapid fermenters: The new strain produced 50 percent more ethanol during a 21-hour period than normal yeast.

The prospect of using this approach to engineer similar tolerance traits in industrial yeast could dramatically impact industrial ethanol production, a multi-step process in which yeast plays a crucial role. First, cornstarch or another polymer of glucose is broken down into single sugar (glucose) molecules by enzymes, and then yeast ferments the glucose into ethanol and carbon dioxide.

Last year, four billion gallons of ethanol were produced from 1.43 billion bushels of corn grain (including kernels, stalks, leaves, cobs, husks) in the United States, according to the Department of Energy. In comparison, the United States consumed about 140 billion gallons of gasoline.

Plextronics has received $750,000 in funding from the Sustainable Energy Fund (SEF) of Central Eastern Pennsylvania to further development of Plexcore PV technology for organic solar cells.

Plexcore PV technology is paving the way for the commercialization of organic solar cells as a leading source of renewable energy. Organic solar cells use extremely thin layers of plastic semiconductors, instead of silicon, to absorb light and create electricity. They can be lightweight, flexible, and can operate well even in low-light conditions. The semiconductors can be printed like inks resulting in a much lower cost of production.

"The Sustainable Energy Fund is pleased to partner with Plextronics in the research and development of photovoltaic and organic lighting projects. These projects are a natural fit with the SEF's mission of developing and investing in economically viable, energy related projects that promote environmentally sound and sustainable energy use," said Dennis Maloskey, Chairman of the Program Related Investment Committee.

Ormat Technologies, Inc. has received the necessary regulatory approvals and the execution of definitive agreements by its subsidiary with the Kenyan Power & Lighting Company (KPLC) for the construction of the second phase of its Olkaria III power project. KPLC is the Kenyan parastatal electricity transmission and distribution company.

Construction of the second phase will commence upon the establishment and exchange of the agreed securities, which is expected to occur in the first quarter of 2007. Completion of phase two is expected approximately 20 months after construction begins.

Upon completion, phase two of the project will add 35 MW to the existing Olkaria III plant, bringing the plants total capacity to approximately 48 MW and total anticipated annual revenues to approximately $32 million.

Dita Bronicki, CEO of Ormat stated; "We are very pleased to be able to continue the private investment in the private power sector in Kenya, bringing to the Kenyan people additional clean energy from an indigenous energy resources."

U.S. Department of Energy (DOE) has released that with DOE funding, a concentrator solar cell produced by Boeing-Spectrolab has recently achieved a world-record conversion efficiency of 40.7 percent, establishing a new milestone in sunlight-to-electricity performance.   This breakthrough may lead to systems with an installation cost of only $3 per watt, producing electricity at a cost of 8 to 10 cents per kilowatt/hour, making solar electricity a more cost-competitive and integral part of our nation's energy mix.

"Reaching this milestone heralds a great achievement for the Department of Energy and for solar energy engineering worldwide," said Assistant Secretary for Energy Efficiency and Renewable Energy Alexander Karsner.   "We are eager to see this accomplishment translate into the marketplace as soon as possible, which has the potential to help reduce our nation's reliance on imported oil and increase our energy security."

Attaining a 40 percent efficient concentrating solar cell means having another technology pathway for producing cost-effective solar electricity.   Almost all of today's solar cell modules do not concentrate sunlight but use only what the sun produces naturally, what researchers call "one sun insolation," which achieves an efficiency of 12 to 18 percent.   However, by using an optical concentrator, sunlight intensity can be increased, squeezing more electricity out of a single solar cell.

The 40.7 percent cell was developed using a unique structure called a multi-junction solar cell.   This type of cell achieves a higher efficiency by capturing more of the solar spectrum. In a multi-junction cell, individual cells are made of layers, where each layer captures part of the sunlight passing through the cell.   This allows the cell to get more energy from the sun's light.

For the past two decades researchers have tried to break the "40 percent efficient" barrier on solar cell devices.   In the early 1980s, DOE began researching what are known as "multi-junction gallium arsenide-based solar cell devices," multi-layered solar cells which converted about 16 percent of the sun's available energy into electricity.   In 1994, DOE's National Renewable Energy laboratory broke the 30 percent barrier, which attracted interest from the space industry.   Most satellites today use these multi-junction cells.

Hadco and SolarOne Solutions have jointly developed a solar powered post top style lamp for decorative lighting applications. This lighting system integrates RT photovoltaic power and LED lighting technology managed by SolarOne's intelligent MC2 controls into a classic Hadco Hagerstown fixture reminiscent of 19th century gas lamps.

This system was designed to address objections of those architects and planners who consider decorative lighting systems powered by bulky solar panels and batteries as aesthetically unappealing. Increases in LED and solar cell efficiency combined with refinements in control technology enable SolarOne's system to produce dramatically more light for longer periods of time for given solar panel/battery dimensions.

"SolarOne's system appears to have reached the cross-over point to bring these elements in at sufficient size to be readily integrated into our standard lighting package and look like they belong," said Hadco's General Manager, Chris Hammelef; "Un-tethered from the grid, who knows where the new markets for our lights will come from."

Each solar powered lamp will offset an estimated 4,000 lbs. of green house gases annually, while providing the peace of mind that it will be operational, even during disasters and emergencies when the grid may be down.

Canada's ability to generate "Green Power" was given a boost by the government's announcement of the ecoEnergy Renewable Power program. The program, designed to cover the deployment of 4,000 MW of low-impact renewable energy, was applauded by the Clean Air Renewable Energy Coalition. The Coalition has been pushing for such mechanisms since it was launched in late 2000.

"This announcement restores most of the green power commitment that the previous government had already made," said Marlo Raynolds, Executive Director for the Pembina Institute. "It's a step forward but much more remains to be done to create an internationally competitive climate change and energy strategy for Canada."

The Coalition produced its "Vision of a Low-Impact Renewable Energy Future for Canada" (see link at http://www.cleanairrenewableenergycoalition.com/documents/Executivesummary%20Hi%20Res.pdf).

The Coalition's goal, as defined in the "Vision" document is to have low-impact renewable energy account for a minimum of 7 percent of Canada's electricity production in 2010, and 15 percent by 2020. An analysis of the employment impacts of the "Vision" document indicates that 20,000 jobs would be created by 2015 in meeting the goal.

The Coalition is now challenging all political parties in Canada to endorse a green power production incentive that supports 12,000 MW of power - and to support its implementation after the next election. The Coalition called for this in the fall of 2005 and presented the concept to all parties at the House of Commons Standing Committee on Finance at its pre-budget consultation session in Calgary in October of 2005.

They said it couldn't be done. And that's what really motivated UD polymer chemist Chris Snively and Jochen Lauterbach, professor of chemical engineering at UD. For years, polymer chemistry textbooks have stated that a whole class of little molecules called 1, 2-disubstituted ethylenes could not be transformed into polymers--the stuff of which plastics and other materials are made.

However, the UD scientists were determined to prove the textbooks wrong. As a result of their persistence, the researchers have discovered a new class of ultra-thin polymer films with potential applications ranging from coating tiny microelectronic devices to plastic solar cells.

The research focused on formerly nonpolymerizable ethylenes. Among them are several compounds that are derived from natural sources, such as cinnamon and are FDA-approved for use in fragrances and foods. One of the compounds is found in milkshakes, according to the scientists.

"There's been a rule that these molecules wouldn't polymerize," Snively, who is a research associate in Lauterbach's laboratory group, noted. "When I first saw that in a textbook when I was in graduate school, I said to myself, 'Don't tell me I can't do this.'"

Polymerization is a chemical reaction in which monomers, which are small molecules with repeating structural units, join together to form a long chain-like molecule--a polymer. Each polymer typically consists of 1,000 or more of these monomer "building blocks." There are lots of natural polymers in the world, ranging from the DNA in our bodies to chewing gum. Plastics, of course, are one of the most common groups of manmade polymers.

Since the late 1990s, Lauterbach and Snively have been developing a method to make extremely thin polymer layers on surfaces. These nanofilms--at least 1,000 times thinner than a human hair--are becoming increasingly important as coatings for optics, solar cells, electrical insulators, advanced sensors and numerous other applications. Formerly, to make a pound of polymer, scientists would take a monomer and a solvent and subject them to heat or light. Recently, Lauterbach and Snively developed a new polymer-making technique that eliminates the need for a solvent.

Their deposition-polymerization (DP) process takes place in a vacuum chamber, where the air is pumped out and the pressure is similar to outer space. The material to be coated, such as a piece of metal, is placed in the chamber, and the metal is cooled below the monomer's freezing point, which causes the monomer vapor to condense on the metal. Then the resulting film is exposed to ultraviolet light to initiate polymerization.

The two-step process allows for the formation of uniform, defect-free films with thicknesses that can be controlled to within billionths of a meter. The process is fairly "green," in that not only are no solvents used, but there also is very low energy consumption using this method, according to Lauterbach.

While their polymerization technique was reported a few years ago, the class of materials the UD scientists have applied it to lately is new and unique. The scientists also want to find out if the materials may be stronger, tougher or possess unique properties compared to other polymers.

"We can make nanometer-thick films, but we can't make a gram of the material yet," Snively noted. "We're working on ways to scale up the process."

The scientists say their collaboration has been so productive not just because their personalities mesh but because knowledge in each of their respective disciplines is essential to solving the scientific questions they seek to answer.

This effort, which focuses on transforming UD graduate students into "energy experts" through interdisciplinary, problem-based research, is supported by a five-year, $3.1 million grant from the National Science Foundation's Integrative Graduate Education and Research Training (IGERT) program.

UD's program, which began this fall, includes students and faculty from electrical and computer engineering, mechanical engineering, chemical engineering, materials science, chemistry, physics, economics and policy.

Canada has now installed a record breaking 657 MW of new wind energy capacity in 2006, representing more than $1 billion in investment, and shattering the previous annual installation record of 240 MW set in 2005. As a result, Canada's total installed wind energy capacity sits at 1,341 MW, a virtual doubling of the 684 MW in place at the start of the year, and enough capacity to meet the electricity needs of 406,000 Canadian homes.

"Wind energy is an emerging Canadian success story and 2006 will be remembered as the year that our country first began to seriously capture the economic and environmental benefits of wind energy deployment," said Robert Hornung, President of the Canadian Wind Energy Association (CanWEA).

"Wind energy projects provide substantial economic benefits to rural communities across Canada through investment, job creation, lease income for landowners, and a new tax base for municipal governments."

Wind energy projects have already been commissioned this year in Alberta, Saskatchewan, Manitoba, Ontario and Nova Scotia; additional facilities in Quebec and Prince Edward Island are also expected to come on line before the end of the year. These projects include Canada's largest wind farm, the 189 MW Prince Wind Energy Project in Ontario, as well as several projects of less than 1 MW in Nova Scotia. Ontario is now the jurisdiction with the most installed wind energy capacity in Canada (413 MW), followed by Alberta (384 MW), Quebec (212 MW) and Saskatchewan (171 MW).

The patented SL product series uses a flat panel design and can provide light for a full dusk to dawn operation.   Not only is the solar lighting system certified to this high standard, but the attachment to the pole has also been certified, eliminating any weak points that may cause the system to not withstand the high winds.  

"We have put a substantial amount of work into making sure that all the stresses brought on by such a high wind event have been compensated for.   We have certified results documenting a 50 percent safety factory beyond the 150 MPH Schedule D requirements," states Tom Ward, VP of sales and marketing.   "SOL Inc. knows how critical this can be having personally gone through the recent 2004 and 2005 active hurricane seasons. Having light even when grid power fails will help communities stabilize local conditions in these critical times."

Wind Power
February 7-9, 2007
Hyatt Regency La Jolla at Aventine, La Jolla, CA

Join the wind industry's leading project developers, lenders, investors and financial innovators at Wind Power Finance & Investment Summit 2007 as they discuss what promises to be another incredible year in the wind industry. With record breaking new megawatts, major consolidations, rising asset values, turbine shortages, capital surpluses, continuing innovation of financial structures, merchant power, municipal power, hedge products, and the emergence of major new financial and strategic investors, and the looming expiration of the PTC, these major dealmakers of the wind industry will discuss these and other cutting edge developments, as well as the various challenges and prospects for 2007 and beyond.

For Summit updates, visit www.infocastinc.com/wind07.html or call (818) 888-4444.

Organic Photovoltaics

This conference will bring together leading technologists to discuss the challenges facing organic photovoltaics and lessons to be learned from achievements within the organic LEDs and organic electronics industries. The conference will focus on business issues facing the industry, including market size and growth potential, technical advances and hurdles, application potential, and production economics.

This conference will bring together industry experts, manufacturers, researchers, and end users for a balanced, comprehensive discussion of the opportunities and challenges surrounding photovoltaic technology. Participants will examine future production, current challenges, and breakthroughs in photovoltaic technology. In addition to covering technological requirements for photovoltaics, the conference will facilitate discussion of market structure, investment, and capital expense. The basic question that this meeting will address is "What role do photovoltaics play in the future of green technology?"