{"id":112692,"date":"2022-07-18T07:10:00","date_gmt":"2022-07-18T05:10:00","guid":{"rendered":"https:\/\/renewable-carbon.eu\/news\/?p=112692"},"modified":"2022-07-13T10:39:43","modified_gmt":"2022-07-13T08:39:43","slug":"bacteria-for-blastoff-using-microbes-to-make-supercharged-new-rocket-fuel","status":"publish","type":"post","link":"https:\/\/renewable-carbon.eu\/news\/bacteria-for-blastoff-using-microbes-to-make-supercharged-new-rocket-fuel\/","title":{"rendered":"Bacteria for Blastoff: Using Microbes to Make Supercharged New Rocket Fuel"},"content":{"rendered":"\n\n\n
\"A
A culture of the Streptomyces bacteria that makes the jawsamycin. \u00a9<\/strong> Pablo Cruz-Morales<\/figcaption><\/figure><\/div>\n\n\n\n

Converting petroleum into fuels involves crude chemistry first invented by humans in the 1800s. Meanwhile, bacteria have been producing carbon-based energy molecules for billions of years. Which do you think is better at the job?<\/strong><\/p>\n\n\n\n

Well aware of the advantages biology has to offer, a group of biofuel experts led by Lawrence Berkeley National Laboratory (Berkeley Lab) took inspiration from an extraordinary antifungal molecule made by Streptomyces<\/em> bacteria to develop a totally new type of fuel that has projected energy density greater than the most advanced heavy-duty fuels used today, including the rocket fuels used by NASA.<\/p>\n\n\n\n

\u201cThis biosynthetic pathway provides a clean route to highly energy-dense fuels that, prior to this work, could only be produced from petroleum using a highly toxic synthesis process,\u201d said project leader Jay Keasling<\/strong>, a synthetic biology pioneer and CEO of the Department of Energy\u2019s Joint BioEnergy Institute (JBEI)<\/a>. \u201cAs these fuels would be produced from bacteria fed with plant matter \u2013 which is made from carbon dioxide pulled from the atmosphere \u2013 burning them in engines will significantly reduce the amount of added greenhouse gas relative to any fuel generated from petroleum.\u201d<\/p><\/blockquote>\n\n\n\n

The incredible energy potential of these fuel candidate molecules, called POP-FAMEs (for polycylcopropanated fatty acid methyl esters), comes from the fundamental chemistry of their structures. Polycylcopropanated molecules contain multiple triangle-shaped three-carbon rings that force each carbon-carbon bond into a sharp 60-degree angle. The potential energy in this strained bond translates into more energy for combustion than can be achieved with the larger ring structures or carbon-carbon chains typically found in fuels. In addition, these structures enable fuel molecules to pack tightly together in a small volume, increasing the mass \u2013 and therefore the total energy \u2013 of fuel that fits in any given tank.<\/p>\n\n\n\n

\u201cWith petrochemical fuels, you get kind of a soup of different molecules and you don\u2019t have a lot of fine control over those chemical structures. But that\u2019s what we used for a long time and we designed all of our engines to run on petroleum derivatives,\u201d said Eric Sundstrom<\/strong>, an author on the paper describing POP fuel candidates published in the journal Joule<\/a>, and a research scientist at Berkeley Lab\u2019s Advanced Biofuels and Bioproducts Process Development Unit<\/a> (ABPDU).<\/p>

\u201cThe larger consortium behind this work, Co-Optima<\/a>, was funded to think about not just recreating the same fuels from biobased feedstocks, but how we can make new fuels with better properties,\u201d said Sundstrom<\/strong>. \u201cThe question that led to this is: \u2018What kinds of interesting structures can biology make that petrochemistry can\u2019t make?\u2019\u201d<\/p><\/blockquote>\n\n\n\n

A quest for the ring(s)<\/h3>\n\n\n\n

Keasling, who is also a professor at UC Berkeley, had his eye on cyclopropane molecules for a long time. He had scoured the scientific literature for organic compounds with three-carbon rings and found just two known examples, both made by Streptomyces<\/em> bacteria that are nearly impossible to grow in a lab environment. Fortunately, one of the molecules had been studied and genetically analyzed due to interest in its antifungal properties. Discovered in 1990, the natural product is named jawsamycin, because its unprecedented five cyclopropane rings make it look like a jaw filled with pointy teeth.<\/p>\n\n\n\n

Keasling\u2019s team, comprised of JBEI and ABPDU scientists, studied the genes from the original strain (S. roseoverticillatus) <\/em>that encode the jawsamycin-building enzymes and took a deep dive into the genomes of related Streptomyces, <\/em>looking for a combination of enzymes that could make a molecule with jawsamycin\u2019s toothy rings while skipping the other parts of the structure. Like a baker rewriting recipes to invent the perfect dessert, the team hoped to remix existing bacterial machinery to create a new molecule with ready-to-burn fuel properties.<\/p>\n\n\n\n

First author Pablo Cruz-Morales<\/strong> was able to assemble all the necessary ingredients to make POP-FAMEs after discovering new cyclopropane-making enzymes in a strain called\u00a0S. albireticuli.\u00a0<\/em>\u201cWe searched in thousands of genomes for pathways that naturally make what we needed. That way we avoided the engineering that may or may not work and used nature\u2019s best solution,\u201d said Cruz-Morales<\/strong>, a senior researcher at the Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark and the co-principal investigator of the yeast natural products lab with Keasling.<\/p><\/blockquote>\n\n\n\n

Unfortunately, the bacteria weren\u2019t as cooperative when it came to productivity. Ubiquitous in soils on every continent,\u00a0Streptomyces<\/em>\u00a0are famous for their ability to make unusual chemicals. <\/p>\n\n\n\n

\u201cA lot of the drugs used today, such as immunosuppressants, antibiotics, and anti-cancer drugs, are made by engineered\u00a0Streptomyces,\u201d\u00a0<\/em>said Cruz-Morales<\/strong>. \u201cBut they are very capricious and they\u2019re not nice to work with in the lab. They\u2019re talented, but they\u2019re divas.\u201d <\/p><\/blockquote>\n\n\n\n

When two different engineered\u00a0Streptomyces<\/em>\u00a0failed to make POP-FAMEs in sufficient quantities, he and his colleagues had to copy their newly arranged gene cluster into a more \u201ctame\u201d relative.<\/p>\n\n\n\n

The resulting fatty acids contain up to seven cyclopropane rings chained on a carbon backbone, earning them the name fuelimycins. In a process similar to biodiesel production, these molecules require only one additional chemical processing step before they can serve as a fuel.<\/p>\n\n\n\n

Now we\u2019re cooking with cyclopropane<\/h3>\n\n\n\n

Though they still haven\u2019t produced enough fuel candidate molecules for field tests \u2013 \u201cyou need 10 kilograms of fuel to do a test in a real rocket engine, and we\u2019re not there yet,\u201d Cruz-Morales explained with a laugh \u2013 they were able to evaluate Keasling\u2019s predictions about energy density.<\/p>\n\n\n\n

Colleagues at Pacific Northwest National Laboratory analyzed the POP-FAMEs with nuclear magnetic resonance spectroscopy to prove the presence of the elusive cyclopropane rings. And collaborators at Sandia National Laboratories used computer simulations to estimate how the compounds would perform compared to conventional fuels.<\/p>\n\n\n\n

The simulation data suggest that POP fuel candidates are safe and stable at room temperature and will have energy density values of more than 50 megajoules per liter after chemical processing. Regular gasoline has a value of 32 megajoules per liter, JetA, the most common jet fuel, and RP-1, a popular kerosene-based rocket fuel, have around 35.<\/p>\n\n\n\n

\"An
An extract of jawsamycin extracted from the capricious bacteria. \u00a9<\/strong> Pablo Cruz-Morales<\/figcaption><\/figure><\/div>\n\n\n\n

During the course of their research, the team discovered that their POP-FAMEs are very close in structure to an experimental petroleum-based rocket fuel called Syntin developed in the 1960s by the Soviet Union space agency and used for several successful Soyuz rocket launches in the 70s and 80s. Despite its powerful performance, Syntin manufacturing was halted due to high costs and the unpleasant process involved: a series of synthetic reactions with toxic byproducts and an unstable, explosive intermediate.<\/p>\n\n\n\n

\u201cAlthough POP-FAMEs share similar structures to Syntin, many have superior energy densities. Higher energy densities allow for lower fuel volumes, which in a rocket can allow for increased payloads and decreased overall emissions,\u201d said author Alexander Landera<\/strong>, a staff scientist at Sandia<\/strong>. One of the team\u2019s next goals to create a process to remove the two oxygen atoms on each molecule, which add dead weight. \u201cWhen blended into a jet fuel, properly deoxygenated versions of POP-FAMEs may provide a similar benefit,\u201d Landera added.<\/p><\/blockquote>\n\n\n\n

Since publishing their proof-of-concept paper, the scientists have begun work to increase the bacteria\u2019s production efficiency even further to generate enough for combustion testing. They are also investigating how the multi-enzyme production pathway could be modified to create polycyclopropanated molecules of different lengths. <\/p>\n\n\n\n

\u201cWe\u2019re working on tuning the chain length to target specific applications,\u201d said Sundstrom<\/strong>. \u201cLonger chain fuels would be solids, well-suited to certain rocket fuel applications, shorter chains might be better for jet fuel, and in the middle might be a diesel-alternative molecule.\u201d<\/p>

Author Corinne Scown, JBEI\u2019s Director of Technoeconomic Analysis<\/strong>, added: \u201cEnergy density is everything when it comes to aviation and rocketry and this is where biology can really shine. The team can make fuel molecules tailored to the applications we need in those rapidly evolving sectors.\u201d<\/p><\/blockquote>\n\n\n\n

Eventually, the scientists hope to engineer the process into a workhorse bacteria strain that could produce large quantities of POP molecules from plant waste food sources (like inedible agricultural residue and brush cleared for wildfire prevention), potentially making the ultimate carbon-neutral fuel<\/a>.<\/p>\n\n\n\n

Who\u2019s up for some eco-friendly space travel?<\/p>\n\n\n\n

About Lawrence Berkeley National Laboratory<\/h3>\n\n\n\n

Founded in 1931 on the belief that the biggest scientific challenges are best addressed by teams, Lawrence Berkeley National Laboratory<\/a> and its scientists have been recognized with 14 Nobel Prizes. Today, Berkeley Lab researchers develop sustainable energy and environmental solutions, create useful new materials, advance the frontiers of computing, and probe the mysteries of life, matter, and the universe. Scientists from around the world rely on the Lab\u2019s facilities for their own discovery science. Berkeley Lab is a multiprogram national laboratory, managed by the University of California for the U.S. Department of Energy\u2019s Office of Science.<\/p>\n\n\n\n

DOE\u2019s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov\/science<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

Converting petroleum into fuels involves crude chemistry first invented by humans in the 1800s. Meanwhile, bacteria have been producing carbon-based energy molecules for billions of years. Which do you think is better at the job? Well aware of the advantages biology has to offer, a group of biofuel experts led by Lawrence Berkeley National Laboratory (Berkeley […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"none","nova_meta_subtitle":"Scientists have developed a new class of energy-dense biofuels based on one of nature\u2019s most unique molecules","footnotes":""},"categories":[5572],"tags":[13383,5838,5714,10408,15849,12615],"supplier":[20637,2869,2440,3827],"class_list":["post-112692","post","type-post","status-publish","format-standard","hentry","category-bio-based","tag-bacteria","tag-bioeconomy","tag-biofuels","tag-greenchemistry","tag-kerosene","tag-microbes","supplier-advanced-biofuels-and-bioproducts-process-development-unit-abpdu","supplier-joint-bioenergy-institute-jbei","supplier-lawrence-berkeley-national-laboratory","supplier-nasa"],"_links":{"self":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/112692","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/comments?post=112692"}],"version-history":[{"count":0,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/112692\/revisions"}],"wp:attachment":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/media?parent=112692"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/categories?post=112692"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/tags?post=112692"},{"taxonomy":"supplier","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/supplier?post=112692"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}