Genetically Engineered E. Coli Shows Increased Hydrogen Production Up to 141 Times Greater Than Wild Type
29 January 2008
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| Schematic of fermentative hydrogen production in E. coli. Hydrogen is produced from formate by the formate hydrogen lyase (FHL) system, which is activated by FhlA and repressed by HycA. Evolved hydrogen is consumed through the hydrogen uptake activity of hydrogenase 1 and hydrogenase 2. Click to enlarge. |
Researchers at Texas A&M University have genetically modified a strain of E. coli to produce a substantial increase in its fermentative production of hydrogen from formate—up to 141 times greater than in a wild type. In addition, the hydrogen yield from glucose was increased by 50%, and there was threefold higher hydrogen production from glucose with this strain.
Professor Thomas Wood and his team detail their results in an open access paper in the inaugural issue of Microbial Biotechnology, a new journal from Blackwell Synergy published jointly with the Society for Applied Microbiology.
As a means to possibly help regulate internal pH and to regulate external pH by removing toxic formate, E. coli produces hydrogen from formate, the researchers note. Hydrogen is consumed by E. coli hydrogenase 1 and hydrogenase 2. There are also two additional formate dehydrogenases which serve to consume formate. The team leveraged these different factors to enhance hydrogen production by inducing multiple mutations in a single strain.
Escherichia coli has three active hydrogenases, and the genes involved in the regulation of the formate hydrogen lyase (FHL) system for synthesizing hydrogen from formate via hydrogenase 3 were also manipulated to enhance hydrogen production. Specifically, we altered regulation of FHL by controlling the regulators HycA and FhlA, removed hydrogen consumption by hydrogenases 1 and 2 via the hyaB and hybC mutations, and re-directed formate metabolism using the fdnG, fdoG, narG, focA, fnr and focB mutations.
Wood acknowledges that there is still much work to be done before his research translates into any kind of commercial application.
Take your house, for example. The size of the reactor that we’d need today if we implemented this technology would be less than the size of a 250-gallon fuel tank found in the typical east-coast home. I’m not finished with this yet, but at this point if we implemented the technology right now, you or a machine would have to shovel in about the weight of a man every day so that the reactor could provide enough hydrogen to take care of the average American home for a 24-hour period. We’re trying to make bacteria so it doesn’t require 80 kilograms; it will be closer to 8 kilograms.
—Thomas Wood
Resources
Toshinari Maeda, Viviana Sanchez-Torres, Thomas K. Wood (2008) Metabolic engineering to enhance bacterial hydrogen production Microbial Biotechnology 1 (1), 30–39. doi:10.1111/j.1751-7915.2007.00003.x
Let me get something straight: these guys are essentially proposing a biodigester that instead of producing methane and CO2, produces hydrogen and CO2. Right?
Granted I've seen that Hydrogen ICEs can run at exceptionally high thermal efficiencies (43% comes to mind), is that really worth the headache of having to deal with cross contamination from your (organic) input?
Posted by: GreenPlease | 29 January 2008 at 07:01 PM
One would need to have aerstanding of the productivity of the original organism.
The safety or risk of environmental escape needs very careful analysis and these sorts of matters are probably outside of general understanding.
But if the first 3 golden rules ,safety safety safety, are addressed.
41 times or 14,100 % above the wild strain.
If these sorts of figures can be safely applied that would make for efficiency undreamed of in most other areas.
The value of such numbers could have an important part to play and I tend to see merit in comparing the potential harmful effects against the known damages we are facing now.
Posted by: arnold | 29 January 2008 at 09:05 PM
oops 4,100% sounds better.
also seen in context this is an indication of the power (for good or harm) of this new science.
Posted by: arnold | 29 January 2008 at 09:08 PM
I hope that they have safety protocols on something like this. Just because they can do this in a lab does not mean that they should.
Posted by: sjc | 30 January 2008 at 04:53 AM
Up 141 times indicates an increase in efficiency, and is certainly good progress, but does not indicate a good efficiency. Just as likely the initial efficiency was abysmal.
Posted by: | 30 January 2008 at 06:11 AM
Could someone explain the following please?
"In addition, the hydrogen yield from glucose was increased by 50%, and there was threefold higher hydrogen production from glucose with this strain."
Note that this hydrogen pathway requires glucose as a feedstock. There are plenty of naturally occurring bacteria that can produce methane from non-woody cellulosic waste. IFF you're going to use a gaseous fuel for mobile applications, why keep banging your head against the wall in pursuit of hydrogen. It just doesn't make sense.
Posted by: Rafael Seidl | 30 January 2008 at 07:31 AM
All I could guess is grant money. At Universities, they know what is most likely to get the money, so they write their proposals accordingly.
This is why it is important who is President and the Governors of states in the U.S. They set the priorities for their budgets and if hydrogen is the big deal, that is where the money goes.
Posted by: sjc | 30 January 2008 at 09:27 AM
sjc,
the figureheads in these political offices do little more today than take orders. The world you experience via media and online is little more than a bumbling simulation of life. What does make a difference is genuine concern and outspokenness in support of sustainable living.
Genuine - not fabricated.
Posted by: sulleny | 30 January 2008 at 04:35 PM
Where is the glucose going to come from?
Posted by: Emphyrio | 01 February 2008 at 05:32 AM
I'm thinking its the formic acid feed they are exited about and they allude to the possibility of running an average east coast household on just 8 kilos ~litres of the stuff.
Thats a lot of vitaminB.
the efficiency gains would then be 41,000%.
It does seem like of a low base tough.
Posted by: Arnold | 01 February 2008 at 07:39 PM
sir your invention is great i want to know that from some amout of (i.e.1 k.g.) glucose the energy production? And this type of hydrogen production is dangereous or not And how can we use it in car .
Posted by: yagnesh | 20 February 2008 at 07:41 AM
Hello:
I graduate of the Acayucan Tecnolologycal Institute, actually do my titulation project named HYDROGEN PRODUCTION BY E. COLI. I need your help for recopilation of information than can help me in this work. I desires meet with this paper and to get my Title professional as soon as possible. Can i help me please?
Posted by: Rosendo | 05 June 2008 at 09:50 PM