Can genetically engineered Nitrogen fixing bacteria help fight globalwarming?

Nope, that's backwards. Most plants rely on nitrogen that they obtain
from dissolved nitrogen compounds (NO, ammonia,nitrates, etc.) in the
soil. "Nitrogen-fixing" plants obtain nitrogne from bacteria that fix
it from the atmosphere (by converting N2 to ammonia.)

This is why trying to increase plant biomass usually requires input of
nitrogen fertilizers.

Yes, making other plants nitrogen-fixing would be spiffy, but you also
have to consider something else: Once a plant dies, all the CO2 that
has been sequestered in its tissues goes right back into the atmosphere
through burning, decay, etc.

M. Reed

monique <[Only registered users see links. ].tamu.edu> wrote:


Is that supposed to be bad?

Isn't that called "carbon neutral"?

Dust to Dust, Air to Air.

Whata Fool wrote:

Your final carbon tax....

"Ouroboros_Rex" <[Only registered users see links. ]> wrote in
news:fnt7hv$usg$[Only registered users see links. ].uiuc.edu:

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More recent research indicates that this may actually be true, the
question does remain about how much is caused by man.



This is quite false. We use oxygen as an electron donor for the
reduction of hydrogen. Plants use carbon dioxide as a source of carbon
which is used as a building block for biochemicals.



Most plants get nitrogen from the water, about 1/3 of plants get
nitrogen from the soil, and a small number use symbiotic relationships
to get nitrogen from bacteria that get it from the air.



Several species of grass do have such a relationship, Dactylus
glomeratus is one.



The orchid family is right up there too.


Usually it is easier to play with one chromosome than with 40.


Actually, you probably have to alter both, as both partners need to
have some reliance on the other. For instance, most nitrogen fixing
plants produce a variant of hemoglobin that helps lower oxygen
concentration around the bacteria, which vastly improves the fixation
rate.


Not all the subsequent statements depend on the first one. For
instance, it is a good idea to reduce dependence on nitrogen
fertilizers, regardless of any effect it may have on atmospheric carbon
dioxide levels.

Sean

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This is a very complicated "what if" question. I doubt engineering
plants to fix nitrogen would have a major impact on global warming for
the following reasons:

1. Plant nitrogen fixation requires a lot of photosynthetic energy.
Plants that naturally fix nitrogen often produce less dry matter if
they have to fix all their own nitrogen than when they are fertilized
with nitrogen.

2. The main reason to engineer plants to fix nitrogen is to save on
the cost of fertilizers. Fertilizer production uses a lot of fossil
fuel, and contributes to global warming, so there might be some
savings in fossil fuel use in fertilizer production. However, that
fossil fuel will simply be burned for something else given the
increasing demand for fossil fuels.

3. Plants that will be engineered to fix nitrogen will be high value
food crops such as corn, wheat and rice. The biomass those food plants
produce is simply plowed under or burned each season so no carbon
dioxide is permanently removed from the air.

4. Plant growth is often limited by factors other than nitrogen,
especially water, temperature, other mineral nutrients, insects, plant
diseases, etc. Plants engineered to fix nitrogen will not
automatically have greater growth rates than nonengineered plants.

5. Fighting global warming by sequestering recently produced plant dry
matter cannot have a significant impact because we are burning fossil
fuels and lowering the world's photosynthetic capacity via forest
destruction, building, paving, etc. at such a rapid rate. One estimate
is that one gallon of gasoline required 98 tons of buried plant
matter.

"Bad Mileage: 98 tons of plants per gallon"
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David R. Hershey
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Probably. One may as well go all the way
though.

Plants need three things to grow:
water/minerals, CO2/O2, sunlight.

These three things are abundant on the
surface of the oceans, therefore GM plants of
the "water-hyacinth" variety might be
convinced to grow while floating on the
surface.

Some plants such as kelp (which have small
air-filled bladders to keep them buoyant)
have little trouble with seawater, and any
floating variety would be easy to harvest and
process; like whales!

Compare this with Canola which is a GM
rapeseed plant, and the ease at which it
grows in vast flat areas and how easy it is
to harvest with mechanical devices.

Large masses of floating weeds would have a
calming effect on the ocean surface (like
"oil on troubled waters").

The Sargasso sea (calmer than most) might be
a good place to start.

P.S.

try
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for a ready-made biomass.