Striking the right balance: Researchers counteract biofuel toxicity in microbes

Advanced biofuels – liquid transportation fuels derived from the cellulosic biomass of perennial grasses and other non-food plants, as well as from agricultural waste – are highly touted as potential replacements for gasoline, diesel and jet fuels. Equally touted is the synthesis of these fuels through the use of microbes. However, many of the best candidate compounds for advanced biofuels are toxic to microbes, which presents a "production versus survival" conundrum. Researchers at the U.S. Department of Energy (DOE)'s Joint BioEnergy Institute (JBEI) have provided a solution to this problem by developing a library of microbial efflux pumps that were shown to significantly reduce the toxicity of seven representative biofuels in engineered strains of Escherichia coli.

"Working with all available microbial genome sequence data, we generated a library of largely uncharacterized genes and were able to devise a simple but highly effective strategy to identify efflux pumps that could alleviate biofuel toxicity in E. coli and, as a consequence, help improve biofuel production," says Aindrila Mukhopadhyay, a chemist with JBEI's Fuels Synthesis Division, who led this research.
"In order for microbial biofuel production to be cost effective, yields must exceed native microbial tolerance levels, necessitating the development of stress-tolerant microbe strains," Mukhopadhyay says. "It is crucial that we improve tolerance in parallel with the development of metabolic pathways for the production of next-generation biofuels."
"Sequenced bacterial genomes include many efflux pumps but remain a largely unexplored resource for use in engineering fuel tolerance," Mukhopadhyay says.
"This metric allowed us to rank the complete set of pumps and select a subset that represented a uniform distribution of candidate genes," says Mukhopadhyay. "To construct the library, we amplified efflux pump operons from the genomic DNA of the selected bacteria, cloned them into a vector, and transformed the vector into an E. coli host strain."
"We focused on the A. borkumensis pump and tested it in a strain of host microbe engineered to produce the limonene jet fuel precursor," Mukhopadhyay says. "Microbes expressing the pump produced significantly more limonene than those with no pump, providing an important proof of principle demonstration that efflux pumps that increase tolerance to exogenous biofuel can also improve the yield of a production host."
"We believe our bioprospecting strategy for biofuel tolerance mechanisms is going to be a valuable and widely applicable tool in the biotechnology field for engineering new microbial production strains," Mukhopadhyay says.

Striking the right balance: Researchers counteract biofuel toxicity in microbes

Advanced biofuels – liquid transportation fuels derived from the cellulosic biomass of perennial grasses and other non-food plants, as well as from agricultural waste – are highly ...

Wed 11 May 11 from Phys.org

Researchers counteract biofuel toxicity in microbes

Researchers at the Joint BioEnergy Institute have created a library of microbial efflux pumps that reduce toxicity and boost production of biofuels in engineered strains of microbes. This library ...

Thu 12 May 11 from R&D Mag

Striking the right balance: JBEI researchers counteract biofuel toxicity in microbes

Advanced biofuels - liquid transportation fuels derived from the cellulosic biomass of perennial grasses and other non-food plants, as well as from agricultural waste - are highly touted as ...

Wed 11 May 11 from Labspaces.net

Striking the right balance: JBEI researchers counteract biofuel toxicity in microbes, Wed 11 May 11 from R&D Mag

Striking the right balance: JBEI researchers counteract biofuel toxicity in microbes, Wed 11 May 11 from Eurekalert

Developing advanced biofuels: Researchers counteract biofuel toxicity in microbes

Researchers have created a library of microbial efflux pumps that reduce toxicity and boost production of biofuels in engineered strains of microbes. This library and the bioprospecting strategy ...

Wed 11 May 11 from ScienceDaily

  • Pages: 1

Bookmark

Bookmark and Share