wrote:
In article ,
Rafael Almeida wrote:

Ivan Kobrinsky wrote:

For this feat they are using completely special light.
Instead of the sun the green sulfur bacteria use the weak
jets of hot sources of the deep sea for their photosynthesis.

Hum... photo-synthesis, photo is greek for light, right? The bacterias
you described seems to use the heat energy to do whatever is done and
not light energy, therefore it couldn't be called photosynthesis, could
it? I'm not a biologist and i don't even know much about it, but that
just seemed wrong.


It seemed strange to me too, but if these hot water jets are as hot as
350C, they would be hot enough to emit some near-infrared and even a
bit of red light by black-body radiation, at the tail end of the curve.
Still, even if it emits a little red light the energy source would be
heat, as the generates little light. For what i know any eletromagnetic
wave that we can't see is just eletromagnetic wave, not light

Hey! this is rather good. Thanks for the links, which I have bookmarked.

Grandma was right; a picture is worth a thousand words.




wrote in message
ups.com...
Estimates of global photosynthesis by NASA, the Intergovernmental Panel
on Climate Change and others are that roughly 50% occurs in the oceans
and 50% occurs on land. I have seen older textbooks with estimates
60/40 both ways so estimates vary. The current 50/50 estimates may
change as more accurate techniques to measure global photosynthesis are
employed.

http://www.nasa.gov/home/hqnews/2005...o_problem.html
http://www.newstarget.com/005139.html
http://www.noc.soton.ac.uk/JRD/SCHOO...phsynth01.html

The oceans are about twice the area of land but ocean photosynthesis is
often lower than on land as the color maps in the following NASA
website indicate:

http://earthobservatory.nasa.gov/Newsroom/NPP/npp.html

David R. Hershey

wrote:
Estimates of global photosynthesis by NASA, the Intergovernmental Panel
on Climate Change and others are that roughly 50% occurs in the oceans
and 50% occurs on land. I have seen older textbooks with estimates
60/40 both ways so estimates vary. The current 50/50 estimates may
change as more accurate techniques to measure global photosynthesis are
employed.

http://www.nasa.gov/home/hqnews/2005...o_problem.html
http://www.newstarget.com/005139.html
http://www.noc.soton.ac.uk/JRD/SCHOO...phsynth01.html

The oceans are about twice the area of land but ocean photosynthesis is
often lower than on land as the color maps in the following NASA
website indicate:

http://earthobservatory.nasa.gov/Newsroom/NPP/npp.html

David R. Hershey

Hum... But doesn't the land trees use more oxygen than the bacterias and
algas (i'm not sure about the name of it in english)? Then wouldn't the
relation (oxygen produced)/(oxygen used) be greater in the ocean?

In article ,
Rafael Almeida wrote:
wrote:
In article ,
Rafael Almeida wrote:

Ivan Kobrinsky wrote:

For this feat they are using completely special light.
Instead of the sun the green sulfur bacteria use the weak
jets of hot sources of the deep sea for their photosynthesis.

Hum... photo-synthesis, photo is greek for light, right? The bacterias
you described seems to use the heat energy to do whatever is done and
not light energy, therefore it couldn't be called photosynthesis, could
it? I'm not a biologist and i don't even know much about it, but that
just seemed wrong.

It seemed strange to me too, but if these hot water jets are as hot as
350C, they would be hot enough to emit some near-infrared and even a
bit of red light by black-body radiation, at the tail end of the curve.

Still, even if it emits a little red light the energy source would be
heat, as the generates little light. For what i know any eletromagnetic
wave that we can't see is just eletromagnetic wave, not light

Well, if the reaction is the usual one in photosynthesis, where a photon
is the energy source, even if it isn't a photon of human-visible light,
I think we'd probably have to call it photosynthesis. There are lots of
ways of acquiring usable energy from temperature differences, including
steam engines, etc, but I don't think any living organisms use them. If
anyone knows of one, please correct me! I suppose a deep ocean vent,
where water at 4C is adjacent to water at 350C would be a place to look
for such bizarre and hard to imagine adaptations.

I'm very curious to know more about these bacteria, and whether energy
from this light source is a significant source of energy to them, or an
adjunct to the well-known chemosynthesis based on oxidizing H2S popular
with Archaeobacteria in unusual environments. I hope Ivan can provide
us with some sources of information.

wrote:
Well, if the reaction is the usual one in photosynthesis, where a photon
is the energy source, even if it isn't a photon of human-visible light,
I think we'd probably have to call it photosynthesis. There are lots of
ways of acquiring usable energy from temperature differences, including
steam engines, etc, but I don't think any living organisms use them. If
anyone knows of one, please correct me! I suppose a deep ocean vent,
where water at 4C is adjacent to water at 350C would be a place to look
for such bizarre and hard to imagine adaptations.

I'm very curious to know more about these bacteria, and whether energy
from this light source is a significant source of energy to them, or an
adjunct to the well-known chemosynthesis based on oxidizing H2S popular
with Archaeobacteria in unusual environments. I hope Ivan can provide
us with some sources of information.
I'm curious also. I don't think they would be able to do photosynthesis
and chemosynthesis, it seems too complex for a bacteria. In order to
keep things simple it probably only uses one source of energy and, if it
gives too little energy than it would have another constraints on itself
that would allow it to live with little energy. But i could be entirely
wrong as all i know is high school biology.

The NASA graphs show Net Primary Productivity in kg carbon per square
meter per year. The summary equation for photosynthesis indicates that
one O2 is produced per carbon fixed so it could also be expressed in kg
O2 rather than kg carbon if a conversion factor was used.

I've never heard of an oxygen produced to oxygen consumed ratio. There
is a respiratory quotient, the ratio of CO2 respired to O2 consumed,
that varies depending on the substance being respired. Respiratory
quotient is measured for nonphotosynthetic organisms or
nonphotosynthetic plant parts such as roots.


David R. Hershey

wrote:
In article ,
Rafael Almeida wrote:
Ivan Kobrinsky wrote:
For this feat they are using completely special light.
Instead of the sun the green sulfur bacteria use the weak
jets of hot sources of the deep sea for their photosynthesis.
Hum... photo-synthesis, photo is greek for light, right? The bacterias
you described seems to use the heat energy to do whatever is done and
not light energy, therefore it couldn't be called photosynthesis, could
it? I'm not a biologist and i don't even know much about it, but that
just seemed wrong.

It seemed strange to me too, but if these hot water jets are as hot as
350C, they would be hot enough to emit some near-infrared and even a
bit of red light by black-body radiation, at the tail end of the curve.

Ivan, do you have any references for this idea that deep ocean vent
bacteria can photosynthesize from this source of light? It's an
interesting idea, and a new one to me. I'd like to read more about it.

I don't think it would be one of the main oxygen source anyway, so it's
a good enough approximation to consider only the oxygen generated by the
things that live right on top of the ocean water. Althought your
considerations are interesting, they might have been posted with a
different subject.

That's true. Btw, Ivan, ignore Cereus. He gets his jollies by trying to
prove he's superior to everybody else here. Arguing with him is pointless
and just gives him more excuses to engage in name-calling and other
childish behaviours. Most of us just ignore him, so he has to wait for
new participants to play with.

Most unfortunately, Ivan appears to have decided not to bother with a
group containing the self-appointed Cerberus; and I don't blame him. He
seemed to me like a man who had the references to at his fingertips;
but it's been reported recently in Britain, just as Ivan described. I
heard it on BBC Radio 4 last week, but I think it's been in New
Scientist. Ggling got, among others, the following, which is a
starting-place:
http://www.pnas.org/cgi/content/abstract/102/26/9306

--
Mike.

They are not using photosynthesis...they are using chemosynthesis.
Chemosynthetic bacteria use not the sun, but chemical energy to make
food. They use hydrogen sulfide gas coming from the vents in the same
way that plants use carbon dioxide and water.

Do a google search for chemosynthetic bacteria for more information...
-Scott

wrote:
In article ,
Rafael Almeida wrote:

Ivan Kobrinsky wrote:

For this feat they are using completely special light.
Instead of the sun the green sulfur bacteria use the weak
jets of hot sources of the deep sea for their photosynthesis.

Hum... photo-synthesis, photo is greek for light, right? The bacterias
you described seems to use the heat energy to do whatever is done and
not light energy, therefore it couldn't be called photosynthesis, could
it? I'm not a biologist and i don't even know much about it, but that
just seemed wrong.


It seemed strange to me too, but if these hot water jets are as hot as
350C, they would be hot enough to emit some near-infrared and even a
bit of red light by black-body radiation, at the tail end of the curve.

Ivan, do you have any references for this idea that deep ocean vent
bacteria can photosynthesize from this source of light? It's an
interesting idea, and a new one to me. I'd like to read more about it.


I don't think it would be one of the main oxygen source anyway, so it's
a good enough approximation to consider only the oxygen generated by the
things that live right on top of the ocean water. Althought your
considerations are interesting, they might have been posted with a
different subject.


That's true. Btw, Ivan, ignore Cereus. He gets his jollies by trying to
prove he's superior to everybody else here. Arguing with him is pointless
and just gives him more excuses to engage in name-calling and other
childish behaviours. Most of us just ignore him, so he has to wait for
new participants to play with.

Ivan Kobrinsky wrote:
Cereus-validus:


Yes. Only as deep as the light reaches.


In the context it is important to consider that sunlight
only can penetrate about 100 to 200 meters deeply into the
sea. In deeper levels (like in more about 2 400 meters sea
depth) photosynthesis is also manufactured. There are living
bacteria, that - like plants - the light for power production
use completely without daylight.

SNIP
It is my understanding that these bacteria are using chemosynthesis and
not photosynthesis.

Here is an article from NOAA:

http://www.pmel.noaa.gov/vents/nemo/...synthesis.html

Chemosynthesis

Most life on Earth is dependent upon photosynthesis, the process by
which plants make energy from sunlight. However, at hydrothermal vents
in the deep ocean a unique ecosystem has evolved in the absense of
sunlight, and its source of energy is completely different:
chemosynthesis. Chemosynthesis is the process by which certain microbes
create energy by mediating chemical reactions. So the animals that live
around hydrothermal vents make their living from the chemicals coming
out of the seafloor in the vent fluids! Because they are a local food
source, hydrothermal vents typically have high biomass, in stark
contrast to the very sparse distribution of animals outside of vent
areas where animals are dependent on food dropping down from above.

Chemosynthetic microbes provide the foundation for biological
colonization of vents. Chemosynthetic microbes live on or below the
seafloor, and even within the bodies of other vent animals as symbionts.
Where microbial mat covers the seafloor around vents, grazers such as
snails, limpets, and scaleworms eat the mat, and predators come to eat
the grazers. Tubeworms flourish in small clumps, waving in the warm
fluids. A typical picture of an active hydrothermal vent is therefore
one with shimmering warm hydrothermal fluids, tubeworms and many other
vent species, all densely clustered around the vent, with white
microbial mat material covering the surrounding area.

Steve Austin wrote in
news
They are not using photosynthesis...they are using chemosynthesis.
Chemosynthetic bacteria use not the sun, but chemical energy to
make food. They use hydrogen sulfide gas coming from the vents in
the same way that plants use carbon dioxide and water.

Do a google search for chemosynthetic bacteria for more
information... -Scott

Recent discoveries have shined light on the subject. Apparently there
is also a bit of light there, and it is being taken advantage by
organisms to make biological energy using photosynthesis.

It is all over the science news this last week or so.

Sean

Rafael Almeida wrote in
:

wrote:
Estimates of global photosynthesis by NASA, the Intergovernmental
Panel on Climate Change and others are that roughly 50% occurs in
the oceans and 50% occurs on land. I have seen older textbooks
with estimates 60/40 both ways so estimates vary. The current
50/50 estimates may change as more accurate techniques to measure
global photosynthesis are employed.

http://www.nasa.gov/home/hqnews/2005/feb/HQ_05042
_bio_problem.html
http://www.newstarget.com/005139.html
http://www.noc.soton.ac.uk/JRD/SCHOO...phsynth01.html

The oceans are about twice the area of land but ocean
photosynthesis is often lower than on land as the color maps in
the following NASA website indicate:

http://earthobservatory.nasa.gov/Newsroom/NPP/npp.html

David R. Hershey

Hum... But doesn't the land trees use more oxygen than the
bacterias and algas (i'm not sure about the name of it in
english)? Then wouldn't the relation (oxygen produced)/(oxygen
used) be greater in the ocean?

That ratio might be greater, but remember that the ocean is a
nutrient poor environment. Low levels of Iron especially limit
growth. That accounts for the lower levels of photosynthesis in the
oceans.

Sean

In article .com,
Mike Lyle wrote:

seemed to me like a man who had the references to at his fingertips;
but it's been reported recently in Britain, just as Ivan described. I
heard it on BBC Radio 4 last week, but I think it's been in New
Scientist. Ggling got, among others, the following, which is a
starting-place:
http://www.pnas.org/cgi/content/abstract/102/26/9306

Thanks for the ref, Mike. It was in our local newspaper on Wednesday.
Here's the text of the ref:

Published online before print June 20, 2005, 10.1073/pnas.0503674102
PNAS | June 28, 2005 | vol. 102 | no. 26 | 9306-9310

An obligately photosynthetic bacterial anaerobe from a deep-sea
hydrothermal vent

J. Thomas Beatty, Jörg Overmann, Michael T. Lince, Ann K. Manske,
Andrew S. Lang, Robert E. Blankenship, Cindy L. Van Dover,
Tracey A. Martinson and F. Gerald Plumley

I read the article, and it's as Ivan originally described. The
researchers found, propagated and characterised a green sulfur
bacterium from a water sample obtained from the plume of a black smoker
vent in the East Pacific Rise, which was not present in water away from
the plume. Like all GSBs, is it obligately photosynthetic, an anaerobe
which reduces CO2 to organic carbon by oxidizing sulfur compounds.
GSBs are capable of using light of extremely low intensity, and this
critter uses "geothermal radiation that includes wavelengths absorbed
by photosynthetic pigments of this organism". It's related to a couple
of well-known genera of GSB, but the authors haven't named it yet.

They speculate that the bacterium normally lives in a microbial mat
within centimeters of the vent, "eking out an existence by infrequent
harvesting of rare geothermal photons", comparing it to a GSB that
lives at 80m in the Black Sea, which has an in situ division time of
2.8 years. In culture, both grow like crazy.

There's refs to a couple of papers about a bacterium that appears to
use light as an auxiliary source of energy to supplement its
chemotrophic metabolism, but this is the first report of an obligate
phototroph that depends on geothermal light.

Extremely cool stuff. I'm always amazed and delighted when I hear
about how some organism has managed to develop an unusual livelihood in
an unlikely environment. I guess I still have a little of that
childlike sense of wonder after all these years.

Thanks, Sean, I'll check that out.

Sean Houtman wrote:
Steve Austin wrote in
news

They are not using photosynthesis...they are using chemosynthesis.
Chemosynthetic bacteria use not the sun, but chemical energy to
make food. They use hydrogen sulfide gas coming from the vents in
the same way that plants use carbon dioxide and water.

Do a google search for chemosynthetic bacteria for more
information... -Scott


Recent discoveries have shined light on the subject. Apparently there
is also a bit of light there, and it is being taken advantage by
organisms to make biological energy using photosynthesis.

It is all over the science news this last week or so.

Sean

:

I read the article, and it's as Ivan originally described.

Well done, cowboy.

Here's the text of the ref:

Published online before print June 20, 2005, 10.1073/pnas.0503674102
PNAS | June 28, 2005 | vol. 102 | no. 26 | 9306-9310

An obligately photosynthetic bacterial anaerobe from a deep-sea
hydrothermal vent


As my original post shows:

MID . com

| Have a look at online-before-print version that presents
| now the international researcher team in PNAS:
|
| "An obligately photosynthetic bacterial anaerobe from a
| deep-sea hydrothermal vent";
| http://www.pnas.org/cgi/conten=ADt/a...t/0503674102v1