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February 4, 2000

Patent filed on energy discovery: UC Berkeley and Colorado scientists find valuable new source of fuel

By Kathleen Scalise, Public Affairs

BERKELEY--A metabolic switch that triggers algae to turn sunlight into large quantities of hydrogen gas, a valuable fuel, is the subject of a new discovery reported for the first time by University of California, Berkeley, scientists and their Colorado colleagues. The news appears in this month's issue of the journal "Plant Physiology."

"I guess it's the equivalent of striking oil," said UC Berkeley plant and microbial biology professor Tasios Melis. "It was enormously exciting, it was unbelievable."

Melis and postdoctoral associate Liping Zhang of UC Berkeley made the discovery - funded by the U.S. Department of Energy (DOE) Hydrogen Program - with Dr. Michael Seibert, Dr. Maria Ghirardi and postdoctoral associate Marc Forestier of the National Renewable Energy Laboratory (NREL) in Golden, Colorado.

Currently, hydrogen fuel is extracted from natural gas, a non-renewable energy source. The new discovery makes it possible to harness nature's own tool, photosynthesis, to produce the promising alternative fuel from sunlight and water. A joint patent on this new technique for capturing solar energy has been taken out by the two institutions.

So far, only small-scale cultures of the microscopic green alga Chlamydomonas reinhardtii have been examined in the laboratory for their hydrogen production capabilities, Melis said.

"In the future, both small-scale industrial and commercial operations and larger utility photobioreactor complexes can be envisioned using this process," Melis said.

While current production rates are not high enough to make the process immediately viable commercially, the researchers believe that yields could rise by at least tenfold with further research, someday making the technique an attractive fuel-producing option.

Preliminary rough estimates, for instance, suggest it is conceivable that a single, small commercial pond could produce enough hydrogen gas to meet the weekly fuel needs of a dozen or so automobiles, Melis said.

The scientific team is just beginning to test ways to maximize hydrogen production, including varying the particular type of microalga used and its growth conditions.

Many energy experts believe hydrogen gas one day could become the world's best renewable source of energy and an environmentally friendly replacement for fossil fuels.

"Hydrogen is so clean burning that what comes out of the exhaust pipe is pure water," Melis said. "You can drink it."

Engineering advances for hydrogen storage, transportation and utilization, many sponsored by the U.S. DOE Hydrogen Program, are beginning to make the fuel feasible to power automobiles and buses and to generate electricity in this country, Seibert said.

"What has been lacking is a renewable source of hydrogen," he said.

For nearly 60 years, scientists have known that certain types of algae can produce the gas in this way, but only in trace amounts. Despite tinkering with the process, no one has been able to make the yield rise significantly without elaborate and costly procedures until the UC Berkeley and NREL teams made this discovery.

The breakthrough, Melis said, was discovering what he calls a "molecular switch." This is a process by which the cell's usual photosynthetic apparatus can be turned off at will and the cell can be directed to use stored energy with hydrogen as the byproduct.

"The switch is actually very simple to activate," Melis said. "It depends on the absence of an essential element, sulfur, from the microalga growth medium."

The absence of sulfur stops photosynthesis and thus halts the cell's internal production of oxygen. Without oxygen from any source, the anaerobic cells are not able to burn stored fuel in the usual way, through metabolic respiration. In order to survive, they are forced to activate the alternative metabolic pathway, which generates the hydrogen and may be universal in many types of algae.

"They're utilizing stored compounds and bleeding hydrogen just to survive," Melis said. "It's probably an ancient strategy that the organism developed to live in sulfur-poor anaerobic conditions."

He said the alga culture cannot live forever when it is switched over to hydrogen production, but that it can manage for a considerable period of time without negative effects.

The researchers first grow the alga "photosynthetically like every other plant on Earth," Melis said. This allows the green-colored microorganisms to collect sunlight and accumulate a generous supply of carbohydrates and other fuels.

When enough energy has been banked in this manner, the researchers tap it and turn it into hydrogen. To do this, they transfer the liquid alga culture, which resembles a lime-green soft drink, to stoppered one-liter glass bottles with no sulfur present. Then the culture is allowed to consume away all oxygen.

After about 24 hours, photosynthesis and normal metabolic respiration stop, and hydrogen begins to bubble to the top of the bottles and bleed off into tall, hydrogen-collection glass tubes.

"It was actually a surprise when we detected significant amounts of hydrogen coming out of the culture," Melis said. "We thought we would get trace amounts, but we got bulk amounts."

After up to four days of generating an hourly average of about three milliliters of hydrogen per liter of culture, the culture is depleted of stored fuel and must be allowed to return to photosynthesis. Then, two or three days later, it again can be tapped for hydrogen, Melis said.
"The cell culture can go back and forth like this many times," Ghirardi said.

February 3, 2000

Not even Berkeley kids eat sprouts, says new UC Berkeley report on middle school nutrition

By Kathleen Scalise, Public Affairs

BERKELEY--Their parents might be consuming zucchini pancakes and wheat grass juice, but for kids in the city of Berkeley it's mostly thumbs down on fruits and vegetables, according to a new nutrition study by researchers at the University of California, Berkeley.

The survey of middle-school students found teens and preteens in Berkeley eating only half as much produce as national standards recommend. And what little they did eat wasn't exactly carrot sticks and apple chunks.

"Generally, we're talking more like tomatoes, lettuce and onions on hamburgers or sandwiches," said study co-author Patricia Crawford, a UC Berkeley Cooperative Extension nutritionist.

She and UC Berkeley public health professor Gladys Block surveyed 252 students ranging in age from 11 to 15 at Martin Luther King and Willard middle schools in Berkeley. Study participants were asked to report everything they ate over a 24-hour period, whether the food came from school or from home.

Crawford said that, despite Berkeley's fame as a health food mecca, the diet of its children looks much like the rest of the state. The number one vegetable was the potato, which kids enjoyed most in the form of french fries. In the fruit category, packaged, processed juices dominated.

"Twenty percent of the kids reported eating no fruits or vegetables on the day assessed, and 55 percent reported only two or fewer servings of fruits and vegetables," Crawford said.

She said nutritionists recommend five daily servings of produce.

The new data could be discouraging to parents. If even Berkeley kids raised in a climate of whole food and nutrition awareness can't be persuaded to eat their greens, some might think there is no hope to get any kids to eat right. But not so, said Crawford.

Whether food came from home or school made an important difference, she said. Middle-schoolers were more likely to eat the fruits and vegetables provided in lunches brought from home.

"It's about food preference," Crawford said. "Maybe children don't like the fruit cup the school gives them, but Mom knows they like bananas, and that's what she sends, something like that."

Of students in the four ethnic groups surveyed - Latino, Caucasian, Asian and African American - produce consumption ranged from more than three servings daily to less than two, with students of Asian descent reporting the most servings and African American students the fewest.

Crawford and Block's study establishes a baseline record of what Berkeley students were eating prior to the adoption of a new Berkeley Unified School District food policy last August that called for serving more organic and locally grown food in the schools.

"This may be the first school district in the nation to adopt this kind of policy," Crawford said.

In the near future, some Berkeley school lunches will include the harvest from crops the children will grow on school property. These community urban gardening projects could be an exciting development, Crawford said. "Once children are more involved in the production of food," she said, "they are more willing to eat it."

Over the next year, the researchers will track dietary changes in the fruit and vegetable consumption of Berkeley children. Stay tuned, Crawford said, for more news on what the city's kids really eat and whether school policies can make a difference.

Also participating in the study were students from the UC Berkeley nutrition assessment course in the School of Public Health and Berkeley Unified School District administrator Yolanda Huang.

The project was funded by the Berkeley Food Project and the University of California Cooperative Extension.

February 2, 2000

Symposium on pediatric obesity prevention launches CNR Center for Weight and Health

Breakthroughs in nutritional genomics and behavioral research on human dietary needs and habits--not to mention the explosion of fitness programs and purported weight-loss drugs--have failed to reduce the nation's waistline. Childhood obesity, in particular, has risen sharply in the past decade and is now classified as an epidemic by the USDA Center for Nutrition Policy and Promotion.

To address this conundrum, the College's new Center for Weight and Health convened "Pediatric Obesity in the 21st Century: A Research Symposium on Prevention." The October 27 symposium was the inaugural event of the center, formerly the Center for Hunger and Obesity, and attracted more than 100 researchers and representatives from academia, county, state and federal government agencies and nongovernmental and community-based organizations working with youth.

The symposium's goal mirrored that of the center: to pursue interdisciplinary, collaborative approaches in addressing the growing problems of poor nutrition and dietary habits at the state and national levels. Spearheading the symposium were the center's codirectors: Sharon Fleming, professor and associate dean for research, and Cooperative Extension specialists Joanne Ikeda and Patricia Crawford.

After introductory remarks from Fleming, speakers addressed new discoveries in the biological, behavioral, environmental and cultural components of pediatric obesity. Jeffrey Friedman, M.D., a geneticist at Rockefeller University, reviewed recent findings on genetic factors in obesity, a condition now believed to be up to 88 percent heritable in humans. He described the roles of the hypothalamus and leptin, a hormone that has been shown to be instrumental in weight regulation. Obese people (those with a body-mass index above the 95th percentile for their gender and age group) have higher blood leptin levels than others, he noted, and when they diet, the resulting drop in blood leptin levels may make it particularly difficult for them to lose weight.

"The importance of these biological factors cannot be overestimated in human obesity," Friedman said, but added that "they tell only part of the story."

Penn State Professor Leann Birch addressed the critical role of parents' behaviors and attitudes, as well as food preparation practices, in shaping children's diets. She has found that children can learn to self- regulate their eating habits if given alternative food choices; in particular, children given smaller food portions eat less.

Center Codirector Crawford noted that pediatric obesity rates have risen rapidly over the past decade in California and nationally. For reasons that are not clear, the rates are rising fastest among low-income ethnic minorities, including African American, Native American and Hispanic children. Pat Lyons, an Oakland-based registered nurse and consultant, screened a video in which teen-age girls discuss diet and body image. She highlighted the mixed messages girls receive in the media ("eat fat, look thin") and the dangers of size discrimination in reducing girls' self-esteem. Others stressed the need for children to be more physically active and spend less time in front of the television--currently averaging four hours a day. Childhood physical activity expert James Sallis of San Diego State University described his intervention studies in schools and other "real- world" settings to increase physical activity. Echoing a recurrent theme, he said, "Though our understanding of the problem of childhood obesity is better, our situation is worse."

To address this dilemma, attendees participated in afternoon brainstorming sessions. They identified many culprits contributing to pediatric obesity, including the exploding fast-food market and its commercialization, reduced funding for public-school physical education and after-school programs and larger food portions. They also suggested potential allies in future prevention efforts: university research groups, fast- food chains, policy makers, the news media, HMOs and other medical service providers and athletic, philanthropic, parent-teacher and religious organizations. They called for more and better after-school programs incorporating physical activity and market research on how to better promote healthy food to children.

Many noted the insufficient funds available for prevention studies. Such funding will remain elusive unless the public better understands the extent of pediatric obesity, said Laura Brainin-Rodriguez of the Child Health and Disability Prevention Program of the San Francisco Department of Public Health. "A key obstacle will be getting local residents to 'take ownership' of the childhood obesity crisis," she said. "For example, we must make a stronger commitment to increase funding for public parks and their facilities and for after-school programs. We are still struggling with the issue of political will."

The symposium was cosponsored by the International Life Sciences Institute, Kellogg Corporation and USDA Team Nutrition.


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Patent filed on energy discovery: UC Berkeley and Colorado scientists find valuable new source of fuel
Not even Berkeley kids eat sprouts, says new UC Berkeley report on middle school nutrition
Symposium on pediatric obesity prevention launches CNR Center for Weight and Health


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