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Part III: Dissimilatory Bacteria in Uranium Reduction

Last time, we explored how dissimilatory bacteria can be used to generate electricity in devices called Microbial Fuel Cells. In part one, I mentioned that the dissimilatory properties of bacteria like Shewanella can potentially also be used for solving part of the problem of radioactive uranium contaminations. When I mentioned this idea to my friend who is a soil scientist, I realized that I did not know how these bacteria can be used to contain uranium contamination. Curious about how exactly this works, I found a review article titled “Uranium Reduction” in the Annual Review of Microbiology written by Judy D. Wall and Lee R. Krumholz (Vol. 60: 149-166, Oct 2006). Following is a summary of what I found. Uranium is a metal with the symbol U on the periodic table. It has the atomic number 92 which means that it has 92 protons and electrons. In nature, occurs in three different forms U-238 (~ 99.238 %), U-235 (0.711 %), and U-234 (0.0058%) where each number refers to the combined num...

Part II: Microbial Fuel Cells (MFC)

I can’t believe how fast time passes. I have been meaning on writing this post up for a long time now. In the last post, I just was introducing Shewanella onedeinensis and its ability to transfer electrons from a variety of organic substrates to metal oxides. Today, we shall look at one possible application for such a microbe: using bacteria to make electricity. This is done through contraptions called Microbial Fuel Cells (MFCs) but to understand MFCs we need to first understand how fuel cells work. There is going to be some detail. But the take-home message here though is: We can use certain bacteria to make electricity out of waste. A fuel cell is a device that produces electricity as long as one provides an external source of fuel and a source that accepts electrons known as oxidants. This is different from normal batteries because batteries simply release the electrical energy stored within them. They get tossed once they are used up. In the case of rechargeable batteries, e...

Dissimilatory Bacteria - Part I: Model Species Shewanella oneidensis -Organism Introduced

Today I came across a really interesting review article with the title “Towards environmental systems biology of Shewanella” that was published in the Nature Reviews journal (August 2008) . I became interested in it because the organism has some very interesting properites. Furthermore, the review article shows how interdisciplinary fields such as biology, chemistry, bioinformatics, and engineering can work together to come up with new ideas. So in the next two posts, I will describe what these little organisms are and explore a few unique potential uses. What is Shewanella spp? Shewanella spp is a genus of many related microbes that lives in many aquatic and sedimentary ecosystems under aerobic as well as anaerobic conditions where it can use many carbon sources as its food. Although the microbes have been in culture collections since the middle of the 20th century, it was not until 1988 that work on a particular member Shewanella oneidensis MR-1 lead to the recognition for mi...

Green Google

As many of you have heard, Google has been very supportive concerning green energy. They have invested in several projects such as Prius Plugin Hybrids , Solar Panels on all their buildings, thermal energy, high-altitude wind energy extraction technologies, an d Engineered Geothermal Systems, with more to come (e.g. ocean-generators). If you read this blog, you are probably interested in this field and Google probably offers one of the best opportunities to work closely with these green technologies. "We are looking for a world-class team to lead this effort. We need creative and motivated entrepreneurs and technologists with expertise in a broad range of areas." (Joblist - click here) Source: http://www.google.com/corporate/green/energy/

Science Team Announced

What's new this week? In a change from what I usually try to write about, significant announcements were made today that will affect the future of our capabilities in science and technology. This week President-Elect Obama has announced his science team in his weekly radio address. Without spin, it has been put up on YouTube: My Own Observations I do not want to read to much into these appointments as I believe the future actions of these appointees will speak more loudly than just their appointments. But I do have a few observations to make. It appears that the coming administration will seek advice based on science, and pragmatism rather than ideology which is a stark contrast to the current Bush administration. While President Bush waited a year before filling the science advisor position late in 2001 , President-Elect Obama has filled up the science advisor position before even officially taking office. This is important because under President George W. Bush, many of the impor...

Diesel from Fungi!

Recently, there has been a lot of talk about a fungus everywhere. What's the deal with this fungus? As we are turning to the future, we need to look for new ways to fund our energy demands. The November edition of the Microbiology Journal suggests one way this could be done. Professor Gary Strobel and his team publish their work on a new fungus which they name Gliocladium roseum (NRRL 50072). The special property of this fungus is that it can make diesel fuel called myco-diesel. (Myco is Latin for fungus.) It does so by breaking down cellulose which is the tough plant cell wall we use for everyday products like paper. Breaking down cellulose normally requires many toxic chemicals and a lot of energy. Therefore, it is quite remarkable that the fungus can make diesel without the need for toxic chemicals. This discovery is important because, in the future, we could use these fungi or the parts of it to make diesel without the need for oil. Why does a fungus want to produce diesel? G...

Obama's new Energy Secretary and EPA head

The US has been abuzz with talk of Obama's picks for his cabinet. One very exciting guy coming up for Secretary of Energy will be Steven Chu , a strong advocate for alternative and renewable energy. He also happens to be a Nobel Laureate for Physics from 1997 (cooling and trapping atoms with lasers). Currently this guy serves as director for the Lawerence Berkeley National Laboratory, pushing the governmental institution towards becoming a world leader in biofuels, artificial photosynthesis, and solar energy technologies, focusing on using carbon-neutral sources. One particular quote stands out to me: "If I were emperor of the world, I would put the pedal to the floor on energy efficiency and conservation for the next decade," he told Reuters in a May 2007 interview. This really excites me because I think he will be able to push the US towards the forefront of the climate change issue. Personally, I'm also proud that a Chinese-American will be spearheading the effo...