Engineering new routes to biochemicals

Living cells can make a vast range of products for us, but they don’t always do it in the most straightforward or efficient way. Shota Atsumi, a chemistry professor at UC Davis, aims to address that through “synthetic biology:” designing and building new biochemical pathways within living cells, based on existing pathways from other living things.

Engineered bacteria use both glucose and acetate, instead of just glucose, as raw material to make isobutyl acetate, which can be used in chemical manufacturing and as fuel.

Engineered bacteria use both glucose and acetate, instead of just glucose, as raw material to make isobutyl acetate, which can be used in chemical manufacturing and as fuel.

Wine cork or screwcap? It depends on aging

The winter holidays have brought many occasions to celebrate with wine and notice the variety of closures now being used to seal wines. As the New Year kicks off, you may find yourself wondering which type of closure is the best and whether that choice is consistent for all wines.

Andrew Waterhouse, professor and wine chemist in the UC Davis Department Viticulture and Enology, offers some research-based advice in an article recently published in The Conversation, an online publication written by academics.

New X-ray technique for surfaces

Surfaces are very interesting to material scientists. The reactions that happen at the point where inside and outside meet, and elements interact with other chemicals or radiation, are important for developing new technology for batteries, fuel cells or photovoltaic panels, for catalysts for the chemical industry, and for understanding environmental chemistry and pollution. Now researchers at UC Davis and the Advanced Light Source at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory have combined two existing methods techniques to come up with a new method for studying surfaces with X-rays. This new technique is called SWAPPS, for Standing Wave Ambient Pressure Photoelectron Spectroscopy.

Making oxygen before life

About one-fifth of the Earth’s atmosphere is oxygen, pumped out by green plants as a result of photosynthesis and used by most living things on the planet to keep our metabolisms running. But before the first photosynthesizing organisms appeared about 2.4 billion years ago, the atmosphere likely contained mostly carbon dioxide, as is the case today on Mars and Venus.

Over the past 40 years, researchers have thought that there must have been a small amount of oxygen in the early atmosphere. Where did this abiotic (“non-life”) oxygen come from? Oxygen reacts quite aggressively with other compounds, so it would not persist for long without some continuous source.

Watching the structure of glass under pressure

Glass has many applications that call for different properties, such as resistance to thermal shock or to chemically harsh environments. Glassmakers commonly use additives such as boron oxide to tweak these properties by changing the atomic structure of glass. Now researchers at the University of California, Davis, have for the first time captured atoms in borosilicate glass flipping from one structure to another as it is placed under high pressure.

The findings may have implications for understanding how glasses and similar “amorphous” materials respond at the atomic scale under stress, said Sabyasachi Sen, professor of materials science at UC Davis. Sen is senior author on a paper describing the work published Aug. 29 in the journal Science.

Reproducing deep-Earth chemistry

A new pressure cell invented by UC Davis researchers makes it possible to simulate chemical reactions deep in the Earth’s crust. The cell allows researchers to perform nuclear magnetic resonance (NMR) measurements on as little as 10 microliters of liquid at pressures up to 20 kiloBar.

“NMR is our window into the chemical world,” said Brent Pautler, a postdoctoral researcher in chemistry at UC Davis and first author on the paper published July 2 in the online edition of the journal Angewandte Chemie. “It lets us see chemical reactions as they are happening.”

Modeling of silicon nanoparticles for solar energy

Silicon nanoparticles embedded in a zinc sulfide matrix are a promising material for new types of solar cell. Computational modeling by Stefan Wipperman, Gergely Zimanyi, Francois Gygi and Giulia Galli at UC Davis and colleagues shows how such a material might work.

“Designing materials with desired properties for renewable energy application is a topic of great current interest in physics, chemistry, and materials science, and one of the goals of the Materials Genome initiative, launched in the US in 2011. Our paper focuses on the search for design rules to predict Earth abundant materials for the efficient conversion of solar energy into electricity,” Zimanyi said in an email.

Probing hydrogen catalyst assembly, part II

Biochemical reactions sometimes have to handle dangerous things in a safe way. New work from researchers at UC Davis and Stanford University shows how cyanide and carbon monoxide are safely bound to an iron atom to construct an enzyme that can generate hydrogen gas. The work is published Jan. 24 in the journal Science.

Producing hydrogen with catalysts based on abundant metals, such as iron, is key to hopes of using hydrogen to replace carbon-based fuels. But before you can make hydrogen, you have to make the catalyst that enables the reaction –something bacteria have been able to do for millennia.

UC Davis work leads to FDA action on antibacterial soaps

On Dec. 16, the U.S. Food and Drug Administration called on manufacturers of antibacterial soaps to demonstrate that the anti-microbial agents have added benefit over  washing with soap and water, and that these additives do not pose unacceptable risks.

This is a major step for the regulatory agency, and there were many academic contributors to the decision. However, the NIEHS Superfund Research Program at UC Davis can be credited with having made a major contribution to raising awareness of the problem.

Humboldt research award for synchrotron expert

Professor Stephen P. Cramer of the UC Davis Department of Chemistry, an expert in synchrotron spectroscopy, has received a Humboldt Research Award from the Alexander von Humboldt Foundation and may now spend up to one year cooperating closely with a team at Helmholtz-Zentrum Berlin (HZB) and Freie Universität Berlin. Cramer was nominated by Professor Emad Aziz, who heads a Joint Lab for “Ultrafast Dynamics in Solution and at Interfaces” at HZB and Freie Universität. Cramer is Advanced Light Source Professor at UC Davis and at the Lawrence Berkeley National Laboratory.