Michael Diatoms too use C4 photosynthesis.
http://www.ncbi.nlm.nih.gov/pubmed/11069177 Unicellular C4 photosynthesis in a marine diatom. Reinfelder JR, Kraepiel AM, Morel FM. Abstract Nearly 50 years ago, inorganic carbon was shown to be fixed in microalgae as the C3 compound phosphoglyceric acid. The enzyme responsible for C3 carbon fixation, ribulose-1,5-bisphosphate carboxylase (Rubisco), however, requires inorganic carbon in the form of CO2 (ref. 2), and Rubisco enzymes from diatoms have half-saturation constants for CO2 of 30-60 microM (ref. 3). As a result, diatoms growing in seawater that contains about 10 microM CO2 may be CO2 limited. Kinetic and growth studies have shown that diatoms can avoid CO2 limitation, but the biochemistry of the underlying mechanisms remains unknown. Here we present evidence that C4 photosynthesis supports carbon assimilation in the marine diatom Thalassiosira weissflogii, thus providing a biochemical explanation for CO2- insensitive photosynthesis in marine diatoms. If C4 photosynthesis is common among marine diatoms, it may account for a significant portion of carbon fixation and export in the ocean, and would explain the greater enrichment of 13C in diatoms compared with other classes of phytoplankton. Unicellular C4 carbon assimilation may have predated the appearance of multicellular C4 plants. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1976569/ regards Bhaskar On Jun 28, 10:13 am, Michael Hayes <voglerl...@gmail.com> wrote: > Hi Folks, > > Mark Capron has proposed Ocean Afforestation within this forum going back to > at least 09. And, much of that work is centered around diatom enhancement > for general CCS and possible biomass harvesting for methane fuel production > and more. C4 halophytes *(1)* could be an important enhancement to that > initial ocean afforestation strategy. > > Wiki *(2)* "C4 plants represent about 5% of Earth's plant biomass and 1% of > its known plant species. Despite this scarcity, they account for about 30% > of terrestrial carbon fixation. Increasing the proportion of C4 plants on > earth could assist > biosequestration<http://en.wikipedia.org/wiki/Biosequestration> of > CO2 and represent an important climate > change<http://en.wikipedia.org/wiki/Climate_change> avoidance > strategy. Present-day C4 plants are concentrated in the tropics (below > latitudes of 45°) where the high air temperature contributes to higher > possible levels of oxygenase activity by > RuBisCO<http://en.wikipedia.org/wiki/RuBisCO>, > which increases rates of photorespiration in C3 plants." > > Although there are many C4 plants that can be used in this type of > CCS strategy, I point out three. The Phyllostachys edulis* *Bamboo *(3)* has > the broadest commercial use of any C4 plants and can also be used > to propagate the physical scale needed of a large scale ocean afforestation > effort...it's cheap and it floats. Also, it provides a matrix for a high > protein mushroom ie. Polyporus phyllostachydis *(4)*. Bambusa oldhamii (the > fastest growing terrestrial plant) *(5)* is a good candidate for maximum CCS > rates. More on bamboo below. The third principle crop being proposed is the > halophyte Salicornia bigelovii *(6)*. > > The Salicornia bigelovii plant has a unique combination of attributes. It > can be used for food, biofuel production and can be irrigated ( > hydroponiclly) with salt water. > > The cost factor: > > The back of the envelope estimates of the needed additional grow space to > off set all anthropomorphic CO2 emissions per yr (30 B t/yr)* (7)* with an > estimated C4 CO2 uptake of 6650 tons per km2/yr, would be roughly equal to > 4.5 M km2. That is about the size of Antarctica. > > Building such a large area operation on shore would have high level > political/land cost considerations. The only place on the planet which can > provide this scale of operation would be the mid-ocean regions (Gyres). Land > based Halophyte farming for biofuel is currently underway at a few sites * > (8)*. > > Wiki; "There are experimental fields of Salicornia in Ras al-Zawr (Saudi > Arabia), Eritrea <http://en.wikipedia.org/wiki/Eritrea> (Northeast Africa) > and Sonora <http://en.wikipedia.org/wiki/Sonora> (Northwest Mexico) aimed at > the production of biodiesel. The company responsible for the Sonora trials > (Global > Seawater <http://www.globalseawater.com/>) claims that between 225 and 250 > gallons of BQ-9000 biodiesel can be produced per hectare (approximately 2.5 > acres) of salicornia, and is promoting a $35 million scheme to create a > 12,000-acre (49 km2) salicornia farm in Bahia de > Kino<http://en.wikipedia.org/wiki/Bahia_de_Kino> > .". > > If the start up cost estimate that is mentioned above is factored out to the > needed 4.5 mil km2 for global CO2 mitigation, we get approximately $6.75 > trillion > in start up cost. If you take a $100 bbl price as being reasonable and > factor out the biofuel production potential of the 4.5 mil km2 effort (20 B > bbl/yr) the ball park yearly income from oil is estimated at around $2 > Trillion not including production/transportation cost. That is a potential > payoff in less than 5-7 years of full operation. Current global oil > consumption is around 30 B/bbl/yr. Also, as a comparison, it is estimated > that the Wall Street Bail Out was/is a 8.5 Trillion deal *(9)*. > > Lets look at the CCS carbon credit factor. If a carbon credit of just $200 > per ton can be established for this project, at 30 b t/yr, that equates out > to $600 B in carbon credit per year. In simply terms, once the mortgage is > paid off, it is financially (environmentally) sustainable. > > Nuts-n-Bolts: > > I propose the specific use of *Salicornia bigelovii *for the following > reasons: > > a. It can be irrigated with salt water. > b. It can be fertilized with mariculture effluent. > c. It can (at this scale) produces around 20 B bbl/yr or 2/3rds of current > world oil demand. > d. The post oil extraction dunnage can be reduced to Na2CO3 for ocean water > pH regulation and/or grow mat soil. Sodium Carbonate would make a good > regional SRM aerosol. > > I propose the cultivation of Bamboo for 3 main reasons: > > a. It is a fast growing natural CCS agent. > b. It is a suitable replacement for many types of lumber which reduces the > need of forest harvesting. > c. It can be used as the principle medium for constructing large floating > growing mats for the halophytes....it floats and provides compost for growth > medium. > > The 2 main start up considerations are: > > a. The need for fresh water irrigation for the bamboo. This fresh water > supply can eventually be worked into the biologics. The growing beds for the > bamboo will be smaller water tight versions of the non water tight larger > salt water halophyte growing mats. The bamboo is mainly used to supply the > main structural material of the floating mats and growth medium for the salt > water crop(s). The quick growing biomass of the bamboo provides the main > means for this floating forest/crop to function. > > b. The need for "starter soil" and "starter" fabricated growing barges. > Thick floating mats will eventually replace the need for starter equipment. > Yet, an initial use of standard vessels would be needed. Buy old ones for > scrap price and tow them out to the site. An older oil tanker would be an > ideal "starter kit". > > How can large growing mats be moored? Well, you don't! First, the mats will > be in the hector size range and thus are within a manageable size for use of > station keeping propulsion. Second, the preferred means of propulsion would > be the use of vectored hypolemnetic aeration "mixers" tethered down into > the thermolcline. This form of station keeping propulsion has > the benefits of biologically supporting the underside of the organic grow > mats, increasing mariculture output and cooling the surface water (great > place to catch tuna). The ideal position for these mats would be in the > central areas of gyres which have very little current and few storms. > > Prototyping a few hectors would just need a reasonably large barge, a small > tender and organics. Constructing the first mats would require purchased > bamboo, soil and seed. > > Conclusion: > > As you may have seen, this is not a completely new idea, in that, I have > simply combined two emerging concepts to create a third. Ocean > Afforestation, as envisioned by Mark Capon et al., has many worthy aspects > which mate up well with this surface C4 effort. The farming of halophytes on > barren lands also has good potential. With a little 3rd world engineering > (ie. use of bamboo) these 3 concepts can be merged to create a more robust > third option. IMHO. > > I believe the main point to consider is the the need for labor. This is a > labor intensive concept. This can actually be a good thing. As any large > scale mid ocean operation will have many operational aspects, the potential > to produce jobs is wide open. We may very well see large scale population > displacements due to GW. Providing housing and jobs which do not conflict > with or strain neighboring areas may turn out to be a blessing for all. If > one country decides to use this method at large scale, it would > significantly reduce it's unemployment rate. > > The numbers I used are soft and I expect I (and others) will find many > errors in this concept. However, it may be a reasonable starting place. If > anything, this short study gave me a much clearer picture of how bad the GW > issue is. Transposing CO2 emissions onto the needed land mass for C4 CCS, is > an eye opener. We will need to build a new continent. Maybe we can start > this one out on the right foot. > > Michael Hayes > (1)http://en.wikipedia.org/wiki/Halophyte > > (2)http://en.wikipedia.org/wiki/C4_carbon_fixation > > (3)http://en.wikipedia.org/wiki/Phyllostachys_edulis > <http://en.wikipedia.org/wiki/Phyllostachys_edulis> > (4)http://en.wikipedia.org/wiki/Polyporus_phyllostachydis > > (5)http://en.wikipedia.org/wiki/Bambusa_oldhamii > > (6)http://en.wikipedia.org/wiki/Salicornia_bigelovii > > (7)http://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emis... > > (8)http://en.wikipedia.org/wiki/Salicornia > > (9)http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/11/26/MNVN14C8Q... -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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