Joint BioEnergy Institute Researchers Combine Systems Biology with Genetic Engineering to Improve Production of Isopentenol in E.Coli
In the on-going effort to develop advanced biofuels as a clean, green and sustainable source of liquid transportation fuels, researchers at the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI) have identified microbial genes that can improve both the tolerance and the production of biogasoline in engineered strains of Escherichia coli.
Aindrila Mukhopadhyay, a chemist who directs the host engineering program for JBEI’s Fuels Synthesis Division, led a study in which transcriptomic data and a synthetic metabolic pathway were used to identify several genes that not only improve tolerance but also production of isopentenol in E.coli. Isopentenol is a five-carbon alcohol that is a highly promising candidate for biogasoline, but, like other short-chained alcohols, is toxic to E.coli at commercial levels of fuel production.
“Our study demonstrates that microbial tolerance engineering using transcriptomics data can be used to identify target genes that improve fuel production,” says Mukhopadhyay, who also holds an appointment with the Lawrence Berkeley National Laboratory (Berkeley Lab)’s Physical Biosciences Division. “Our targets include a regulator for amino acid biosynthesis, and an ABC transporter protein, the first native transporter that improves tolerance to a short-chain alcohol.”
Mukhopadhyay is the corresponding author of a paper describing this study in the journal mBio titled “Improving microbial bio-gasoline production in Escherichia coli using tolerance engineering.” Co-authors are Heather Jensen, Jee Loon Foo, Robert Dahl, Kevin George, Jay Keasling, Taek Soon Lee and Susanna Leong.
The price of gasoline and other petroleum fuels may be dropping for the moment, but atmospheric carbon concentrations are continuing to rise. A highly touted carbon-neutral alternative to petroleum fuels is the microbial production of advanced biofuels from the cellulosic biomass of perennial grasses and other non-food plants, as well as from agricultural waste. However, the toxicity to microbes of many of the best candidate compounds for advanced biofuels presents a “production versus survival” conundrum.
“In order for microbial biofuel production to be cost effective, yields must exceed native microbial tolerance levels, necessitating the development of solvent-tolerant microbial strains,” Mukhopadhyay says. “In parallel with improved tolerance it is also crucial that we improve production.”
To this end, Mukhopadhyay and her group in this new study used transcriptomic data – a measurement of differential expression of gene transcripts in a given genome – to identify 40 E.coli genes that showed increase when exposed to externally added isopentenol. These genes were then overexpressed in E. coli to evaluate their potential for improving isopentenol tolerance. Genes conferring isopentenol tolerance were then co-expressed individually with an isopentenol production metabolic pathway in E.coli to determine which would increase productivity as well.
“MetR, the methionine biosynthesis regulator, improved the titer for isopentenol production by 55-percent,” Mukhopadhyay says. “MdlB, the ABC transporter, facilitated a 12-percent improvement in isopentenol production.”
Mukhopadhyay and her group are especially eager to further investigate the MdlB transporter, which they believe, as the first native transporter gene shown to improve production of a short-chain alcohol, will provide a valuable new avenue for host engineering in biogasoline production.
“The critical point is that you must first identify the genes that can serve as engineering targets, and then test them to find which ones work best,” Mukhopadhyay says. “Now that we have identified MdlB as a target, we are going to examine it in great depth to see how can we improve its function and optimize its use in a production microbe.”
This research was supported by the DOE Office of Science. JBEI is a DOE Office of Science Bioenergy Research Center led by Berkeley Lab.
For more about the research of Aindrila Mukhopadhyay go here
For more about JBEI go here
Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.
DOE’s 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 the Office of Science website at science.energy.gov/.
Lynn Yarris | Eurek Alert!
Building a brain, cell by cell: Researchers make a mini neuron network (of two)
23.05.2018 | Institute of Industrial Science, The University of Tokyo
Research reveals how order first appears in liquid crystals
23.05.2018 | Brown University
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
23.05.2018 | Life Sciences
23.05.2018 | Life Sciences
23.05.2018 | Physics and Astronomy