Yes, completely supplanting fossil fuel is indeed a pipe dream, but someday will be a necessity if we survive that long. Still, in reading the fine print in this paper the ratio of CO2 consumed to lipid produced is generally >0.6, a figure I find remarkably high. The incubations were conducted at 37 deg C so that precludes the use of ambient T in most places without genetic engineering, esp in mitigating Arctic methane. They also found that the use of methane to make lipid was dissimilative, meaning that the carbon is not assimilated and does not become part of the biomass. The use of the term "methanotrophy" to describe methane consumption therefore now needs to be used with great caution unless further evidence is provided. This is an example of methane oxidation providing energy for autotrophic CO2 fixation – a form of chemoautotrophy Greg
From: "euggor...@comcast.net<mailto:euggor...@comcast.net>" <euggor...@comcast.net<mailto:euggor...@comcast.net>> Date: Tuesday, August 13, 2013 11:42 AM To: Default <r...@llnl.gov<mailto:r...@llnl.gov>> Subject: Re: [geo] Coupled CH4 and CO2 Mitigation? Supplanting fossil sources is a pipe dream at least in the US. Getting rid of CO2 and CH4 would be an interesting experiment. If it actually reduces global temperature it would be a real plus. ________________________________ From: "Greg Rau" <r...@llnl.gov<mailto:r...@llnl.gov>> To: "geoengineering" <geoengineering@googlegroups.com<mailto:geoengineering@googlegroups.com>> Sent: Tuesday, August 13, 2013 1:01:07 PM Subject: [geo] Coupled CH4 and CO2 Mitigation? Sorry if this is old news, but in cleaning out my in box I came across this interesting 2012 paper – anaerobic methane oxidation also consumes CO2. So with a bit of biogeoengineering we can pro-actively mitigate CH4 and CO2 simultaneously, +/- take the lipid-rich biomass to produce biofuels, supplanting fossil sources??? Greg Autotrophy as a predominant mode of carbon fixation in anaerobic methane-oxidizing microbial communities 1. Matthias Y. Kellermann<http://www.pnas.org/search?author1=Matthias+Y.+Kellermann&sortspec=date&submit=Submit>a<http://www.pnas.org/content/109/47/19321.full#aff-1>,1<http://www.pnas.org/content/109/47/19321.full#fn-3>,2<http://www.pnas.org/content/109/47/19321.full#fn-4>,3<http://www.pnas.org/content/109/47/19321.full#corresp-1>, 2. Gunter Wegener<http://www.pnas.org/search?author1=Gunter+Wegener&sortspec=date&submit=Submit>b<http://www.pnas.org/content/109/47/19321.full#aff-2>,c<http://www.pnas.org/content/109/47/19321.full#aff-3>,1<http://www.pnas.org/content/109/47/19321.full#fn-3>, 3. Marcus Elvert<http://www.pnas.org/search?author1=Marcus+Elvert&sortspec=date&submit=Submit>a<http://www.pnas.org/content/109/47/19321.full#aff-1>, 4. Marcos Yukio Yoshinaga<http://www.pnas.org/search?author1=Marcos+Yukio+Yoshinaga&sortspec=date&submit=Submit>a<http://www.pnas.org/content/109/47/19321.full#aff-1>, 5. Yu-Shih Lin<http://www.pnas.org/search?author1=Yu-Shih+Lin&sortspec=date&submit=Submit>a<http://www.pnas.org/content/109/47/19321.full#aff-1>, 6. Thomas Holler<http://www.pnas.org/search?author1=Thomas+Holler&sortspec=date&submit=Submit>c<http://www.pnas.org/content/109/47/19321.full#aff-3>, 7. Xavier Prieto Mollar<http://www.pnas.org/search?author1=Xavier+Prieto+Mollar&sortspec=date&submit=Submit>a<http://www.pnas.org/content/109/47/19321.full#aff-1>, 8. Katrin Knittel<http://www.pnas.org/search?author1=Katrin+Knittel&sortspec=date&submit=Submit>c<http://www.pnas.org/content/109/47/19321.full#aff-3>, and 9. Kai-Uwe Hinrichs<http://www.pnas.org/search?author1=Kai-Uwe+Hinrichs&sortspec=date&submit=Submit>a<http://www.pnas.org/content/109/47/19321.full#aff-1> +<http://www.pnas.org/content/109/47/19321.full> Author Affiliations 1. aOrganic Geochemistry Group, MARUM-Center for Marine Environmental Sciences and Department of Geosciences, University of Bremen, D-28359 Bremen, Germany; 2. bAlfred Wegener Institute for Polar and Marine Research, Research Group for Deep Sea Ecology and Technology, D-27515 Bremerhaven, Germany; and 3. cMax Planck Institute for Marine Microbiology, D-28359 Bremen, Germany 1. Edited by Donald E. Canfield, University of Southern Denmark, Odense M, Denmark, and approved October 5, 2012 (received for review May 24, 2012) Next Section<http://www.pnas.org/content/109/47/19321.full#sec-1> Abstract The methane-rich, hydrothermally heated sediments of the Guaymas Basin are inhabited by thermophilic microorganisms, including anaerobic methane-oxidizing archaea (mainly ANME-1) and sulfate-reducing bacteria (e.g., HotSeep-1 cluster). We studied the microbial carbon flow in ANME-1/ HotSeep-1 enrichments in stable-isotope–probing experiments with and without methane. The relative incorporation of 13C from either dissolved inorganic carbon or methane into lipids revealed that methane-oxidizing archaea assimilated primarily inorganic carbon. This assimilation is strongly accelerated in the presence of methane. Experiments with simultaneous amendments of both 13C-labeled dissolved inorganic carbon and deuterated water provided further insights into production rates of individual lipids derived from members of the methane-oxidizing community as well as their carbon sources used for lipid biosynthesis. In the presence of methane, all prominent lipids carried a dual isotopic signal indicative of their origin from primarily autotrophic microbes. In the absence of methane, archaeal lipid production ceased and bacterial lipid production dropped by 90%; the lipids produced by the residual fraction of the metabolically active bacterial community predominantly carried a heterotrophic signal. Collectively our results strongly suggest that the studied ANME-1 archaea oxidize methane but assimilate inorganic carbon and should thus be classified as methane-oxidizing chemoorganoautotrophs. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com<mailto:geoengineering+unsubscr...@googlegroups.com>. To post to this group, send email to geoengineering@googlegroups.com<mailto:geoengineering@googlegroups.com>. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out.
