Biodiversity-based services in biofuels: an emerging picture

Expanding experiments to better predict biofuel impacts

On the wing – grassland birds

Six-legged service providers

Insect-vectored plant viruses

Soil bacteria and greenhouse gases

Spotlight on Collaborators

Describing plant communities

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Contact: Ron Raines, (608) 262-8588, rtraines@wisc.edu

MADISON – A University of Wiscosnin-Madison research team has developed a promising new chemical method to liberate the sugar molecules trapped inside inedible plant biomass, a key step in the creation of cellulosic biofuels.

The approach, which is described in the March 9 issue of the Proceedings of the National Academy of Sciences, can convert three-quarters of the sugars locked up in raw corn stover into simple, fermentable sugars, making it an attractive alternative to the enzyme-based approaches currently favored by biofuels researchers.

“Our chemical process is extremely efficient,” says Ron Raines, a UW-Madison professor of biochemistry and chemistry. “It also has marked advantages over the existing processes-both chemical or enzymatic-for producing sugars from biomass.”

Working under a strong federal mandate, scientists across the nation are developing next-generation biofuels from inedible plant materials such as corn stover, switchgrass and wood chips. Unlike most ethanol on the market today, these so-called cellulosic biofuels would not be derived from food sources, potentially reducing the stress on food systems. But the complex structure of plant material keeps cellulose’s energy-rich sugars locked up in tangled webs, making the process of converting it to fuel difficult. In recent years, scientists have been trying to find and engineer enzymes that can break down the sugars more efficiently, potentially opening the door to the commercial production of fuel from cellulose.

Raines’ chemical approach, which he developed with graduate student Joe Binder, a doctoral candidate in the chemistry department, on the other hand, relies on a mixture of an ionic liquid and dilute acid-both of which can slip past lignin-to dissolve the long chains of sugars in biomass and break them up into individual molecules of glucose and xylose.

Over the course of the reaction, they added water to the mixture to prevent unwanted byproducts from forming. After two rounds of such treatment, a sample of corn stover gave up about 70 percent of its glucose and 79 percent of its xylose, a 75 percent sugar yield overall. From there, the researchers used ion-exclusion chromatography to separate the sugars from the reaction mixture, as well as the ionic liquid, for reuse.

The sugar yields obtained using this method, says Raines, approach those achieved using enzymes to break down raw biomass. And chemicals, he notes, are more robust and less expensive than enzymes-and require no pretreatment of the biomass sample. “In the biofuels race,” says Raines, “I feel this sort of chemical approach has a good shot at winning.”

Raines and Binder subsequently used microbes to ferment the sugars they collected into ethanol. All told, says Raines, using this integrated process, they were able to convert half of the sugars available in plant biomass into liquid fuel.

To make it work at the industrial scale, however, a number of hurdles will need to be overcome, including the near-perfect recovery of the ionic liquid, which is expensive, in order to make the whole process economical. Nevertheless, says Raines, the technology is ready for the right entrepreneur.

“This work could have substantial short-term economic and political impacts,” he says.

Raines’ project was supported by the Great Lakes Bioenergy Research Center, a U.S. Department of Energy Bioenergy Research Center located at UW-Madison, as well as a National Science Foundation Graduate Research Fellowship awarded to Binder.
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-Nicole Miller, (608) 262-3636, nemiller2@wisc.edu

Producing ethanol from corn is relatively easy: the corn’s abundant sugars are readily fermented into alcohol. But using what is essentially a food crop to produce fuel has been criticized as a misuse of resources that can harm both agriculture and the environment.

Better, critics say, to make what is called cellulosic ethanol from leaves and stalks or other crop waste or nonfood crops like switchgrass. The process uses lignocellulose, the basic structural material of all plants and the most abundant organic compound on the planet.

But cellulosic ethanol is more difficult to make. The lignocellulose must first be broken down into sugars, which can then be fermented. Current techniques use costly enzymes or highly concentrated acids that are difficult to handle.

Now, Ronald T. Raines and Joseph B. Binder of the University of Wisconsin are proposing a different way. In a paper in The Proceedings of the National Academy of Sciences, they describe a process that uses an ionic liquid — a salt with a low melting point — in combination with water and acids at lower concentrations to produce fermentable sugars.

The researchers found that water was the key to making the process efficient. Without water, the sugars produced by the action of the ionic liquid and the acid rapidly degraded into other compounds. But water keeps chloride ions in the salt from further reacting with the sugars.

The researchers say their process produces sugar yields approaching those obtained by enzymatic methods. While much work remains, they say the process may prove useful in converting agricultural waste to a useful fuel.

Note: Raines’ project was supported by The Great Lakes Bioenergy Research Center, a U.S. Department of Energy Bioenergy Research Center located at UW-Madison, as well as a National Science Foundation Graduate Research Fellowship awarded to Binder.

CONTACT: Michael Sussman, 608-262-8608, msussman@wisc.edu; Richard Burgess, 608-263-2635, burgess@oncology.wisc.edu

MADISON – On Wednesday, March 10, the University of Wisconsin-Madison campus community and guests will join in celebrating 25 years of operation at the UW-Madison Biotechnology Center.

Formed when some people were frightened by the prospect of genetic engineering, the center has matured into an interdisciplinary hub of the Madison area’s growing biotech business.

Only three Madison-area companies were working in biotech back in 1985, says Dick Burgess, the center’s founding director. Now the area has more than 150 biotech firms, and the state is recognized as a premier site for biotechnology research and industry.

The center maintains close ties with industry and with scientists in many departments across campus, says current director Michael Sussman, a professor of biochemistry. One focus is providing analytical equipment. “We’ve developed a core facility for next-generation DNA sequencing,” Sussman says, which can gobble up DNA and spit out data on its structure at astonishing rates. “Other units on campus are starting to helping us procure these instruments and put them in the biotech center sequencing facility, where we can operate them for everyone on campus.”

The center can also analyze the proteins and small molecules whose structures and function that are encoded within the DNA and are critical links in the interaction between genes and environment that determine who we are.

Wisconsin has deep roots in biotechnologies such as farming and brewing, and Burgess was determined that the center address state problems from the first. One early project looked at “greener” ways to make paper pulp with fungus instead of synthetic chemicals. Nowadays, the center is helping analyze and alter the metabolism of microbes and crops to ease the conversion of their biomass into sugar and then biofuels.

A second ongoing focus has been education and outreach, says Burgess, now a professor emeritus of oncology. “We had to find ways of countering the negativism. We tried to provide a positive face to the science and the scientists who were doing biotech research at the university.”

Sussman says the biotech center has grown into an integral part of a university with unparalleled prowess in biology. “This campus is one of the greatest biological campuses on Earth. We have 750 tenured professors in biology, and probably a greater diversity, quality and quantity of biology research than at any place outside of the National Institutes of Health.”

As biotech advances, nagging uncertainty continues about the instructions passed down in genes. The first “reading” of the human genome, which occurred about a decade ago, produced more questions than answers, forcing a reassessment, for example, of large stretches of the genome that were once considered “junk” but actually control when genes operate.

The biotech center remains an asset for the broad range of biological scientists on campus. “I find it really exciting to help our faculty and staff do experiments; these analytical methods are opening a completely new way to figure out what biology is doing,” Sussman says. “We are getting fairly good at analyzing the role of DNA and RNA in disease, but why stop there? Let’s also look at the genes and the proteins, all of the small molecules involved in metabolism, all at once.”

The center’s effort to foster greater understanding of the beneficial role high-tech entrepreneurs has paid off. “In the middle 1980s, almost everyone being trained in Madison in biological science was going to the coasts; it was an incredible brain drain,” Burgess says. “Now there are thousands of jobs in the area, and we have attracted a lot of significant talent.”

The 25th anniversary celebration will be held from 2-4:30 p.m. on Wednesday, March 10, in Room 1111 of the Biotechnology Center, 425 Henry Mall.
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- David Tenenbaum, 608-265-8549, djtenenb@wisc.edu

Abstract: With growing demand for bio-based fuels and chemicals, there has been much attention given to the performance of different feedstocks. We have optimized the ammonia fiber expansion (AFEX) pretreatment and fermentation process to convert forage and sweet sorghum bagasse to ethanol. AFEX pretreatment was optimized for forage sorghum and sweet sorghum bagasse. Supplementing xylanase with cellulase during enzymatic hydrolysis increased both glucan and xylan conversion to 90% at 1% glucan loading. High solid loading hydrolyzates from the optimized AFEX conditions were fermented using Saccharomyces cerevisiae 424A (LNH-ST) without any external nutrient supplementation or detoxification. The strain was better able to utilize xylose at pH 6.0 than at pH 4.8, but glycerol production was higher for the former pH than the latter. The maximum final ethanol concentration in the fermentation broth was 30.9 g/L (forage sorghum) and 42.3 g/L (sweet sorghum bagasse). A complete mass balance for the process is given.

SUMMARY
MYB46 functions as a transcriptional switch that turns on the genes necessary for secondary wall biosynthesis.  Elucidating the transcriptional regulatory network immediately downstream of MYB46 is crucial to our understanding of the molecular and biochemical processes involved in the biosynthesis and deposition of secondary walls in plants. To gain insights into MYB46-mediated transcriptional regulation, we first established an inducible secondary wall thickening system in Arabidopsis by expressing MYB46 under the control of dexamethasone-inducible promoter. Then, we used an ATH1 GeneChip microarray and Illumina digital gene expression system to obtain a series of transcriptome profiles with regard to the induction of secondary wall development. These analyses allowed us to identify a group of transcription factors whose expression coincided with or preceded the induction of secondary wall biosynthetic genes. A transient transcriptional activation assay was used to confirm the hierarchical relationships among the transcription factors in the network. The in vivo assay showed that MYB46 transcriptionally activates downstream target transcription factors, three of which (AtC3H14, MYB52 and MYB63) were shown to be able to activate secondary wall biosynthesis genes. AtC3H14 activated the transcription of all of the secondary wall biosynthesis genes tested, suggesting that AtC3H14 may be another master regulator of secondary wall biosynthesis. The transcription factors identified here may include direct activators of secondary wall biosynthesis genes. The present study discovered novel hierarchical relationships among the transcription factors involved in the transcriptional regulation of secondary wall biosynthesis, and generated several testable hypotheses.

Contact: Jason A. Smith, communications director
jsmith@wisconsinacademy.org / 608-263-1692 ext. 21

MADISON—Did you know that 50 million new cars roll off the assembly line each
year—that’s 137,000 cars a day! If this current growth rate continues, there will be over
1 billion motor vehicles on the world’s roads by 2050. With retail gasoline prices on the
rise and a globally dwindling supply of petroleum, we need to find clean and plentiful
means of fuelling the cars of the future. Will Wisconsin’s pioneering efforts in
bioenergy—fuel derived from such renewable sources as plants, trees, and agricultural
waste—today transform the way we drive and live a generation from now?

Tim Donohue, UW–Madison professor of bacteriology and head of the
Great Lakes Bioenergy Research Center, discusses the growing field
of bioenergy in the forthcoming Academy Evenings presentation,
What’s Driving My Car? 2050 Biofuels and Other Sustainable Energy
Sources, as part of the Wisconsin Academy’s “Wisconsin 2050:
Pioneering the Future” series of public forums on the events that will
shape our state’s future.

This free Academy Evenings event will be held on March 16, 2010, from 7:00–8:30 pm, at the Madison Museum
of Contemporary Art lecture hall, Overture Center for the Arts in Madison. Seating is first-come, first served. Doors open at 6:15 pm.

The “Wisconsin 2050: Pioneering the Future” Academy Evenings series is sponsored
by the Pleasant T. Rowland Foundation, Wisconsin Alumni Research Foundation,
University of Wisconsin–Madison, M&I Bank, the Evjue Foundation, and Isthmus
Publishing Company.

About Academy Evenings
Academy Evenings engage the public in a wide variety of topics of public interest and
feature Wisconsin’s leading thinkers, scholars, and artists. These free forums are
intended to encourage public interaction with these leaders in an intimate atmosphere
designed to foster discussion and build community. The Wisconsin Academy of
Sciences, Arts and Letters sponsors Academy Evenings regularly in Overture Center
for the Arts in Madison and at other venues across the state. For more information on
Academy Evenings in your area, visit wisconsinacademy.org.

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3/1/2010

CONTACT: Margaret Broeren, mbroeren@glbrc.wisc.edu, (608) 890-2168, Michael Casler, mdcasler@wisc.edu, (608) 890-0065

MADISON – The March issue of BioEnergy Research exclusively focuses on the U.S. Department of Energy-funded Great Lakes Bioenergy Research Center (GLBRC) and bioenergy research topics ranging from arthropods to cell walls to hydrogen and enzyme improvement.

This is the second of three special issues featuring work from the energy department’s Bioenergy Research Centers.

“This issue provides a snapshot of the diverse range of cutting-edge research within Great Lakes Bioenergy,” says Tim Donohue, GLBRC director and University of Wisconsin-Madison professor of bacteriology. “Readers curious about the latest advances in cellulosic biofuels research will certainly find something that piques their interest.”

The 11 journal articles showcase scientific collaborations at UW-Madison and Michigan State University in four broad research themes: improved biofuels feedstocks, improved conversion into advanced biofuels, sustainable biofuels landscapes, and improved cellulosic biomass processing. Open access to the March issue is available at http://ow.ly/1apjA.

Improved biofuels feedstocks: Committed to improving plant biomass for conversion to liquid fuels, Great Lakes Bioenergy researchers are working to increase energy-rich hydrocarbons in plant tissues and to create plant cell walls that are more easily broken down into their component sugars. Papers contributed by UW-Madison researchers Natalia de Leon, Michael Casler and Chris Schwartz provide a glimpse into the center’s attempts to capitalize on natural genetic mutations to create more suitable feedstocks and methods for deconstructing plant hydrocarbons into liquid fuels.

Improved conversion into advanced biofuels: Scientists are using a variety of natural genetic and genomic approaches to identify organisms and biological systems with unique properties that could increase the efficiency of converting biomass into biofuels. A research group led by UW-Madison engineer Dan Noguera is using a genetic mutant of Rhodobacter sphaeroides to study electron partitioning from nutrients into hydrogen gas.

Sustainable biofuels landscapes: One of the center’s core research areas focuses on the ensuring biological diversity across the agricultural landscape used for bioenergy feedstock production. MSU entomologist Doug Landis’ research group examines abundance and diversity of beneficial insects, including bees, beetles, and flies, in relation to species-richness of cellulosic biofuel crops, while a paper led by MSU microbial ecologist Ederson Jesus examines the mix of bacterial life that lies within the soil.

Improved cellulosic biomass processing: Developing efficient and economical biomass processing technologies will require significant improvements in the properties and combinations of enzymes used to convert plant biomass into liquid fuels. In a review, MSU researcher Goutami Banerjee and his team describe many of the current impediments to bioconversion and the Center’s approaches that include bioprospecting for superior key enzymes, protein engineering and high-level expression in plants. MSU scientist Dahai Gao reports research results of the combination of different enzymes, or enzyme cocktails, and their effect on bioconversion of maize stover.

Finally, the issue highlights high-throughput technology made possible by the center’s enabling technologies group. MSU researcher Nick Santoro describes a robotic platform that provides key measurements that allow researchers to rapidly characterize thousands of plant samples for important traits and bioconversion efficiencies.

About Great Lakes Bioenergy:

The Great Lakes Bioenergy Research Center (GLBRC) is one of three U.S. Department of Energy (DOE) Bioenergy Research Centers funded to make transformational breakthroughs that will form the foundation of new cellulosic biofuels technology. The Center is led by the University of Wisconsin-Madison, with Michigan State University as the major partner.  Additional scientific partners are DOE National Laboratories, other universities and a biotechnology company. For more information, visit http://www.glbrc.org.

About BioEnergy Research:

BioEnergy Research fills a void in the rapidly growing area of feedstock biology research related to biomass, biofuels, and bioenergy. The journal publishes a wide range of articles, including peer-reviewed scientific research, reviews, perspectives and commentary, industry news, and government policy updates. Its coverage brings together a uniquely broad combination of disciplines with a common focus on feedstock biology and science, related to biomass, biofeedstock, and bioenergy production. Open access to this issue is available at: http://ow.ly/1apjA

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Engineers at the University of Wisconsin-Madison on Thursday announced a discovery that advances the renewable-energy research aimed at converting corn stalks or switchgrass into jet fuel.

The research was published in this week’s issue of the journal Science.

One of the researchers involved in the project has a track record in development of renewable green transportation fuels, thanks to his involvement with earlier research that led to the formation of the Madison biofuels firm Virent Energy Systems Inc.

The engineers say this is one step toward making jet fuel from biomass feedstock such as corn stalks or switchgrass.

Work is now under way to develop the most efficient source for the compound, known as gamma-valerolactone, or GVL. GVL is currently used as an herbal food and perfume additive.

A chemical conversion process developed by engineer James Dumesic, professor of chemical and biological engineering, as well as postdoctoral researchers and graduate students at UW-Madison.

The findings will add to research that’s taking place in Madison and elsewhere to investigate renewable sources for transportation fuels. Read the full story