\u201cWe\u2019ve shown that the bacterium Ralstonia eutropha growing with carbon dioxide and hydrogen gas is able to generate significant quantities of diesel-range methyl ketones. This holds the promise of making carbon-neutral biofuels using non-photosynthetic, carbon-dioxide fixing bacteria as a less resource-intensive alternative to making these biofuels from cellulosic biomass,\u201d<\/p><\/blockquote>\n
says microbiologist Harry Beller, who led this research.<\/p>\n
Alternative to Cellulosic Biomass<\/h2>\n
Beller led an earlier study where genetic engineering was used to develop a strain of the bacterium Escherichia coli<\/em> (E. coli) that made methyl ketone compounds from the glucose in cellulosic biomass. Methyl ketones are naturally occurring aliphatic compounds now used in fragrances and flavorings.<\/p>\nBeller and his JBEI colleagues have demonstrated that methyl ketones also have high diesel fuel ratings (cetane numbers), making them strong candidates as advanced biofuels.<\/p>\n
\u201cWe\u2019ve shown that, with the same set of genetic modifications, R. eutropha<\/em> and E. coli<\/em> can make comparable amounts of methyl ketones, but R. eutropha<\/em> is making the ketones from carbon dioxide while E. coli<\/em> is making them from glucose,\u201d said Beller. \u201cThis shows that the methyl ketone pathway that we\u2019ve designed is versatile and able to function well in bacterial hosts with substantially different metabolic lifestyles.\u201d<\/p><\/blockquote>\nExisting strategies for making biofuels to replace gasoline, diesel, or jet fuels in today\u2019s engines and infrastructures are based on extracting fermentable sugars stored in the cellulosic biomass of green plants.<\/p>\n
Hydrogen vs. Solar Power<\/h2>\n
Those sugars represent chemical energy that was converted from solar energy via photosynthesis and provide the carbon atoms needed to make fuels. R. eutropha<\/em> is an ordinary soil bacterium that can naturally use hydrogen rather than sunlight as an energy source for converting carbon dioxide into various organic compounds.<\/p>\nHowever, native strains of R. eutropha<\/em> do not produce detectable levels of methyl ketones and generate very low levels of the fatty acids that are precursors to methyl ketones.<\/p>\n\u201cSince our engineered strains of R. eutropha<\/em> can use fixed carbon dioxide to make methyl ketones, its biofuels don\u2019t require many of the steps needed to convert cellulosic biomass into fuels, such as growing and harvesting the biofuel crop, digesting the lignocellulosic biomass, and enzymatically saccharifying the digested biomass to produce fermentable sugars. The resources needed for these steps could therefore be eliminated if R. eutropha<\/em> were used to make biofuels directly from carbon dioxide,\u201d<\/p><\/blockquote>\nBeller says.<\/p>\n","protected":false},"excerpt":{"rendered":"
Gathering carbon dioxide emitted from natural gas or coal-burning power plants that worsens global warming and using it to produce clean, green, and renewable liquid transport fuels would be a win-win scenario for all concerned, but is it possible? Researchers at the U.S. Department of Energy\u2019s Joint BioEnergy Institute (JBEI) who have evolved a microbe…<\/p>\n","protected":false},"author":1,"featured_media":386,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77],"tags":[20],"_links":{"self":[{"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/posts\/383"}],"collection":[{"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/comments?post=383"}],"version-history":[{"count":1,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/posts\/383\/revisions"}],"predecessor-version":[{"id":590,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/posts\/383\/revisions\/590"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/media\/386"}],"wp:attachment":[{"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/media?parent=383"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/categories?post=383"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/tags?post=383"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}