Currently most energy production is fueled by a variety of
fossil fuels such as natural gas, coal, and oil. There are some obvious
problems with burning fossil fuels to create energy. The pollutants produced
during energy production cannot be properly stored forever and the CO2
levels have a variety of effects on the environment, including ocean
acidification. With the obvious drawbacks of fossil fuels research is being
done in a variety replacement energy sources. These sources include gasoline
producing bacteria, nuclear power, solar energy, wind energy, hydroelectric
power production, and geothermal energy. While some of these solutions are more
environmentally friendly than others, they all have their drawbacks. Most of
them need large boosts in efficiently to make them viable replacements to
fossil fuels in the market place. A combination of multiple sources will be
needed to sustain the amount of energy we will need to meet the power
requirements of future populations.
One
source of energy production that I stumbled across while looking for
interesting articles to write about is the use of microbial fuel cells to
produce electricity. In microbial fuel cells bacteria are used to perform
reactions that generate electricity. In one case researchers developed a fuel
cell to take the wastewater from a brewery and convert it into power and clean
water for future brewing. A link to that is down below. The article I chose to
focus on is a group of researchers using simple E. coli to make power. Originally they researched the mechanisms
behind the production of energy using E.
Coli. They found that while energy production of the bacteria when biomass
was added was measurable there were ways to improve on the process. The
bacteria were not conductive and it was expensive to harvest the energy. The
bacteria secreted Indole, a benzene ring fused to a five membered ring with a
nitrogen on it. Indole can be oxidized by oxygenases from other bacteria, one
of which was subsequently transplanted via plasmid into the bacteria. The
indole and modified E. Coli made nine
times more power than the control microbial fuel cells. This was an interesting
result and shows that bacteria can be designed to perform specific reactions
and produce significantly different amounts of electricity. While the MFCs are
not at all efficient, in the brewery case it led to major savings on wastewater
treatment. This means they can also be designed to purify water after certain industrial
uses. This make them cost efficient for water purification while also being
able to produce power as an added benefit.
Being
able to purify waste products and produce power seems like something the future
needs. Let me know what you thing in the comments below.
For more reading:
Basics on a microbial fuel cell:
Energy from beer article:
A scholarly article on optimizing
fuel cells:
Indole oxidation enhances electricity production in an
E-coli-catalyzed microbial fuel cell.
By: Han, TH; Cho, MH; Lee, J.
It's pretty interesting to know that a gram negative bacteria that lives in the intestines of animals can produce fuel and energy. I wonder what other bacteria's can produce and whether or not they type (negative or positive) affects how much energy is produced.
ReplyDeleteRyan-
ReplyDeleteOne of the main topics in my undergrad seminar on pollution was energy! Although we had discussed many of the commonly known nonrenewable and renewable energy sources, I never knew that bacteria could be used to produce energy. I think this research is really cool and practical considering the desire for clean/renewable energy sources and water purification in the world. However, I do wonder if these bacteria would produce enough energy to satisfy the need, especially compared to other renewable energy sources. It would be interesting to compare the pros and cons of microbio fuel cells to other known sources of energy such as solar, hydro, or wind power.
That seems like it would take a LOT of bacteria! Although E. coli is probably the easiest to transform, I wonder if other bacteria would be better at producing higher amounts of energy. You also say that it's expensive to harvest the energy but that it saved money on wastewater treatment, so it really seems like a give and take type of thing that needs a good balance to achieve the greatest amount of efficiency.
ReplyDeleteIs there any particular reason why E. coli was chosen for this study? Are there any other bacteria that can be used for energy?
ReplyDeleteRyan,
ReplyDeleteI did undergraduate research on the basis of a fuel cell. Basically, I used a Isophthalic acid and different organic solvents to try to figure out what would make this acid re-crystalize in a structure that could expand and contract when materials were added or taken away. Anyway, I agree that trying to figure out a way to use wastewater products in producing energy could be beneficial to our environment. It could eliminate some of the wastes that are being dumped into lakes and streams and turn it into something positive.
I just did a blog over using sewage as a fuel resource. Althought equally interesting, I think I'd rather bacterial be the winner. There are many technique in play to take over for fossil fuels. I wonder which ones will make the cut of both economically feasibility and ease of procedure. Regardless, the strides in research just keep coming! I'm guessing E.coli was used as it is so easily manipulated and grown in labs?
ReplyDeleteSort of a side comment, but there are several universal cellular processes for producing electricity (Kreb's Cycle, e.g.) many of which are used to drive proton pumps. When it comes to biochemistry, it seems that some microbe has a solution for just about any problem. Nice post.
ReplyDelete