Using a newly developed technique, researchers from Japan, Germany and the U.S. have identified a key step in production of hydrogen gas by a bacterial enzyme. Understanding these reactions could be important in developing a clean-fuel economy powered by hydrogen.
The single-celled green alga Chlamydomonas reinhardtii has an iron-based enzyme that can generate hydrogen gas. (JGI)
The team studied hydrogenases – enzymes that catalyze production of hydrogen from two widely distributed organisms: Chlamydomonas reinhardtii, a single-cell algae and Desulfovibrio desulfuricans, a bacterium.
In both cases, their hydrogenase enzymes have an active site with two iron atoms.
Key to Tea’s Benefits May Be in the Soil
By Becky Oskin
Tea has long been linked to human health benefits like preventing cancer and heart disease. But with hundreds of chemical compounds hidden in tea leaves, it is unclear which substances have the strongest effects.
The slew of “healthy” chemicals in tea varies with the variety of plant, how and where it is grown, and how the leaves are processed. Even soil bacteria contribute to a plant’s chemical profile, including its color, taste and aroma.
Full post: Microbes Could Bring Tea to California
(410 words, 1 image, estimated 1:38 mins reading time)
Water ice is peculiar stuff: Even below freezing, when it should be solid, it has a quasi-liquid layer on the outside. That’s what makes ice slippery. In this month’s Three Minute Egghead podcast, UC Davis chemist Davide Donadio describes his recent research looking at the surface of ice and what it has to do with clouds and air pollution.
Computer simulation of the surface of ice shows how layers melt in steps (Credit: Davide Donadio)
Hear more Three Minute Egghead on Soundcloud or iTunes
Related news story: Ice Surface Melts One Step at a Time
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(98 words, 1 image, estimated 24 secs reading time)
By Becky Oskin
Chronicling Earth’s past temperature swings is a basic part of understanding climate change. One of the best records of past ocean temperatures can be found in the shells of marine creatures called foraminifera.
The foraminiferan Neogloboquadrina dutertrei forms a record of ocean conditions as it builds its shell. Photo by J. Fehrenbacher
Known as “forams” for short, these single-celled plankton build microscopic calcite shells. When forams die, their shells fall to the ocean floor and accumulate in sediments that provide a record of past climate. The surface-feeding plankton are natural thermometers because the chemical makeup of foram shells is linked to the environmental conditions they grow in. For example, the levels of magnesium in foram shells reflect the seawater temperature in which they lived.
Full post: Refining the Ocean’s Thermometer
(512 words, 2 images, estimated 2:03 mins reading time)
By Becky Oskin
To find evidence of life on Mars, scientists from UC Davis and the U.S. Geological Survey are chasing clues in Mars-like environments on Earth.
The environment at the Iron Mountain mine near Redding, Calif. is similar to Mars. Amy Williams, Towson University
The researchers hope to find rock patterns and textures that are uniquely linked to microscopic life such as bacteria and algae. “It’s challenging to prove that a mineral was made by a living organism,” said lead study author Amy Williams, an assistant professor at Towson University in Towson, Maryland. Williams led the research as a graduate student at UC Davis. Finding similar textures in Mars rocks could bolster confidence that microscopic shapes in Red Planet rocks were formed by living creatures.
By Becky Oskin
Cyanobacteria, one of Earth’s oldest life forms, offer a promising new source of petroleum-free fuels and chemicals. However, economies of scale currently make it challenging for these tiny creatures to compete with fossil fuels. Now, scientists at UC Davis are closer to meeting these challenges with a new advance that improves the production and growth rate of cyanobacteria.
UC Davis chemist Shota Atsumi is engineering these cyanobacteria to produce biofuels. (Photo by T.J. Ushing)
Visiting scholar Masahiro Kanno, graduate student Austin Carroll and chemistry professor Shota Atsumi introduced new genetic pathways into cyanobacteria that could help make microbe-based chemical production systems smaller and easier to operate.
Compounds Could Be Basis For Devices That Turn Waste Heat Into Electricity
Cage-like compounds called clathrates could be used for harvesting waste heat and turning it into electricity. UC Davis chemists just discovered a whole new class of clathrates, potentially opening new ways to make and apply these materials.
UC Davis chemists discovered a new class of clathrates that break the four-bond rule. The discovery was featured on the cover of the journal Angewandte Chemie (Wiley)
UC Davis entomologist Christian Nansen trained some high-tech analysis on coffee beans, showing that brands were not consistent in content. Photo: Kathy Garvey
By Kathy Keatley Garvey
If your particular brand of coffee doesn’t seem to taste the same from week to week or month to month, you may be right. And it’s not you, it’s the coffee beans.
Agricultural entomologist Christian Nansen of the UC Davis Department of Entomology and Nematology and four colleagues analyzed 15 brands of roasted coffee beans, purchased at an area supermarket on two dates about six months apart, and using hyperspectral imaging technology, found “they were all over the board.”
By Becky Oskin
College students in the STEM fields could see sizable savings thanks to a $600,000 grant awarded to an open source textbook project developed at the University of California, Davis.
The ChemWiki project recently received $600,000 from the National Science Foundation to support further expansion of its open source textbooks into fields including statistics, math, geology, physics, biology and solar energy.
Digital course materials are steadily climbing in use in response to textbook cost concerns, according to an annual survey released in July by the National Association of College Stores. In August, the University of Maryland announced plans to completely eliminate print textbooks this academic year.
At the bottom of a frigid Antarctic lake, a thin layer of green slime is generating a little oasis of oxygen, a team including UC Davis researchers has found. It’s the first modern replica discovered of conditions on Earth two and a half billion years ago, before oxygen became common in the atmosphere. The discovery is reported in a paper in the journal Geology.
The switch from a planet with very little available oxygen to one with an atmosphere much like today’s was one of the major events in Earth’s history, and it was all because some bacteria evolved the ability to photosynthesize. By about 2.4 billion years ago, geochemical records show that oxygen was present all the way to the upper atmosphere, as ozone.