SEP 12, 2018 05:33 PM PDT

Tightening Control of Bacterial Gene Expression

WRITTEN BY: Carmen Leitch

Bacteria are easy to work with; their genes can be manipulated, and it’s usually easy to grow a lot of them. As such, they have a lot of potential as mini-factories that could produce many kinds of chemicals, from therapeutics to fuels. But one hurdle has been finding an affordable way to get the expression of those bacterial genes under control. To overcome that challenge, scientists from the Department of Energy's (DOE) Joint BioEnergy Institute, Lawrence Livermore National Laboratory (LLNL), Lawrence Berkeley National Lab and San Francisco State University have created a system to control gene expression; they called it "Jungle Express." This work has been reported in Nature Communications.

Colorized scanning electron micrograph of Escherichia coli / Image credit: NIAID

"We have created a system that can precisely control the timing and levels of expression of the genes involved in these processes, opening the way for efficient large-scale production at low costs," said LLNL biochemist Michael Thelen, senior author of the paper. "These enhancements to bacterial gene regulation have a potential translation to sustainable bioproduction."

Being able to turn genes on and off is fundamental to research and industry. While there have been ways to do this, they had issues. One difficulty was so-called leaky gene expression; there isn’t tight control of when genes are on or off, and improper regulation meant targets get made incorrectly or at the wrong levels. It was also an expensive problem.

"The key component of this expression system is a DNA binding protein that acts as a gene regulator," said Basel University graduate student Thomas Ruegg, who worked with Helen. "We used a computational approach to predict a small DNA sequence for optimal binding of the regulator protein."

Crystal violet is a common, inexpensive dye. Ruegg found that the dye quickly causes the gene regulator to release, turning gene expression on and generating biochemicals. "In a rational approach, we used the optimized DNA binding site to engineer a robust system in which crystal violet acts as the inducer to trigger efficient gene expression," Ruegg explained.

"Our findings have the potential to overcome the bottlenecks encountered in earlier systems and opens the way for tightly controlled and efficient gene expression that is not restricted to host organism, substrate or scale," Thelen added.

The name the team used, Jungle Express, comes from a rainforest bacterium, which is where the regulator protein from this work is found in nature. Ruegg noted that "it is a fascinating journey to explore the inexhaustible resource of genetic information found in microorganisms, and to decouple it from its native context for the development of novel, useful applications."

Learn more about how bacteria might be used to make valuable compounds from the video; EMBL discusses how to engineer a microbe that produces bioplastic.


Sources: via LLNL, Nature Communications

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
OCT 14, 2018
Genetics & Genomics
OCT 14, 2018
A Gene That can Make Light Touch Feel Painful
Anyone that has had a sunburn knows that even a light brush against the skin, like that from putting on clothes, can become excruciating....
OCT 22, 2018
OCT 22, 2018
How Many Bacteria are There in the World?
Researchers once thought that there were only a few thousand bacterial species on the planet - a gross underestimation....
NOV 03, 2018
Cell & Molecular Biology
NOV 03, 2018
New Insight Into the Regulation of Sleep
Once thought of as supporting structures, researchers are uncovering more roles for astrocytes, a type of cell in the brain with a shape like a star....
NOV 16, 2018
Genetics & Genomics
NOV 16, 2018
Using Light to Control Organ Development
Optogenetics combined genetic engineering with optics to create a way to control cellular behaviors with light....
NOV 27, 2018
NOV 27, 2018
A Genetic Switch During Inflammation
Microglia, CNS immune cells, change their genetic profile during different states of the inflammation spectrum...
DEC 11, 2018
DEC 11, 2018
FDA approves two new drugs for cancers with specific genetic mutations
Last month the FDA approved two new drugs for cancer, both drugs target cancers with specific genetic mutations which made geneticists and oncologists optimistic on the future of cancer thera...
Loading Comments...