Nav: Home

Survival of the hardest working

March 21, 2016

A team of engineers at Washington University in St. Louis discovered a way to improve production of biofuels, pharmaceuticals, materials and other useful chemicals by capitalizing on the work ethic of cells.

The research team, led by Fuzhong Zhang, assistant professor of energy, environmental & chemical engineering in the School of Engineering & Applied Science, discovered that genetically identical microbial cells have different work ethics. The team developed a tool to ensure that the hard-working cells keep working hard and the low-performing cells are eliminated.

The research is published online in Nature Chemical Biology March 21.

When engineering microbes to produce useful chemicals, cells from the same ancestor often perform tasks differently. Using engineered strains of the bacteria E. coli, Zhang's team demonstrated that only a small fraction of cells worked hard to produce the desired chemicals, while the majority of others were content to not work, but to eat nutrients intended for working cells. The different work ethic is not caused by unintended genetic mutations, they found, but rather by "noise" in biology, which is inherent in nature and impossible to eliminate.

To prevent the lazy cells from wasting nutrients, Zhang's team developed a quality-control tool, called PopQC, that can keep the hard-working, high-performing cells working while eliminating the low-performing cells. The team placed a sensor inside the cells that could sense how much work each cell was doing. If the sensor determined that a cell was making a lot of the products, the sensor would trigger a controller to make a protein that allowed the cells to survive and grow. If the sensor determined that the cell was not working hard enough, it remained silent, and the lazy cells died from lack of nutrition or were knocked out by antibiotics.

The team applied PopQC to two engineered strains of E. coli: one designed to produce free fatty acid, a precursor for biofuels or other high-volume chemicals; and one designed to produce tyrosine, an amino acid that can be a precursor to pharmaceuticals. PopQC allowed the hard-working cells to dominate in both cultures and led to threefold enhanced ensemble production of both free fatty acid and tyrosine, Zhang said.

"PopQC could be applied to a variety of biosynthetic pathways and host organisms as long as a proper sensor exists that detects the product in the engineered host," Zhang said. "Because noise is a universal problem in biology, the design principle of this work should inspire engineers from many other fields to improve efficiency of engineered systems."

Zhang has filed a patent application for the design principle with assistance from the university's Office of Technology Management.

Zhang's research interests focus on applying synthetic biology methodologies to develop microbial systems for the sustainable production of biofuels, chemicals and materials with defined structures and controllable properties. He also is interested in developing tools that allow engineered microbes to synthesize target products and to perform complex tasks more efficiently and robustly.

Washington University in St. Louis

Related Biofuels Articles:

Barriers and opportunities in renewable biofuels production
Researchers at Chalmers University of Technology, Sweden, have identified two main challenges for renewable biofuel production from cheap sources.
How biofuels from plant fibers could combat global warming
A study from Colorado State University finds new promise for biofuels produced from switchgrass, a non-edible native grass that grows in many parts of North America.
Calculating the CO2 emissions of biofuels is not enough
A new EU regulation aims to shrink the environmental footprint of biofuels starting in 2021.
Algae cultivation technique could advance biofuels
Washington State University researchers have developed a way to grow algae more efficiently -- in days instead of weeks -- and make the algae more viable for several industries, including biofuels.
Cutting the cost of ethanol, other biofuels and gasoline
Biofuels like the ethanol in US gasoline could get cheaper thanks to experts at Rutgers University-New Brunswick and Michigan State University.
Cellulosic biofuels can benefit the environment if managed correctly
Could cellulosic biofuels -- or liquid energy derived from grasses and wood -- become a green fuel of the future, providing an environmentally sustainable way of meeting energy needs?
Making oil from algae -- towards more efficient biofuels
The mechanism behind oil synthesis within microalgae cells has been revealed by a Japanese research team.
WSU study finds people willing to pay more for new biofuels
When it comes to second generation biofuels, Washington State University research shows that consumers are willing to pay a premium of approximately 11 percent over conventional fuel.
'Super yeast' has the power to improve economics of biofuels
Scientists at the University of Wisconsin-Madison and the Great Lakes Bioenergy Research Center have found a way to nearly double the efficiency with which a commonly used industrial yeast strain converts plant sugars to biofuel.
Biofuels not as 'green' as many think
Statements about biofuels being carbon neutral should be taken with a grain of salt.
More Biofuels News and Biofuels Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.