Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists work to plug microorganisms into the energy grid

19.05.2009
The answer to the looming fuel crisis in the 21st century may be found by thinking small, microscopic in fact. Microscopic organisms from bacteria and cyanobacteria, to fungi and microalgae, are biological factories that are proving to be efficient sources of inexpensive, environmentally friendly biofuels that can serve as alternatives to oil, according to research presented at the 109th General Meeting of the American Society for Microbiology.

"We have been charged to develop the next generation of cellulosic biofuels. When we successfully supply sources of energy to the grid from non-food, cellulosic, parts of plants we will mitigate the food versus fuel debate," says Tim Donohue of the University of Wisconsin, Madison, one of two directors of Department of Energy Bioenergy Research Centers who spoke today in a session at the meeting.

When it comes to alternative fuels, currently ethanol is king. Almost all ethanol produced in the United States is fermented from readily available sugars in corn starch or corn kernels. Producing ethanol from corn has also come under much criticism lately, accused of being responsible for rising food prices.

Researchers are looking at alternate biomasses as food for microorganisms to ferment into ethanol. The most attractive are known as lignocellulosic biomass and include wood residues (including sawmill and paper mill discards), municipal paper waste, agricultural residues (including sugarcane bagasse), dedicated energy crops (like switchgrass) or the non-edible parts of corn like cobs, stalks or stover. The problem is, unlike corn starch, the sugars necessary for fermentation are trapped inside the lignocellulose part of this plant biomass. The key to ending the food versus fuel debate is unlocking the sugars trapped in cellulosic biomass.

To do that, some scientists have taken a page out of the playbook of the pharmaceutical industry. Pharmaceutical companies routinely use a process known as high throughput screening to rapidly test thousands of compounds for potential new drugs. Martin Keller at Oak Ridge National Laboratory, the DOE bioenergy research center director, and his lab have adapted the method to rapidly test poplar tree samples for their ability to give up sugars.

"We for the first time ever have developed a super-screening pipeline to handle thousands of samples. We took samples from approximately 1,300 poplar trees in the northwestern United States and used the screening pipeline to see if there was a difference in sugar release," says Keller. "Trees can be very different. Some trees can be easier to digest, even within the same species."

Keller is not sure why some poplars are more likely to give up their sugars than others. It could be genetic or the result of some environmental factor or a bit of both. They are now conducting experiments, growing poplar saplings under controlled environments to better understand.

In addition to studying the biomass itself, Keller's lab is also looking for microbes or microbial products that can help break it down into simple sugars. They are currently studying a bacterium found in a hot spring in Yellowstone known as Anaerocellum. It grows at approximately 80 degrees Celsius and is what is known as a consolidate bioprocessing microbe: It can not only break down the cellulosic biomass to sugars but ferment it to acetate and ethanol, saving time and money.

"Right now it is expensive to break down cellulosic biomass. That is why we don't have a sustainable biofuels industry. This is what we as a center are working to overcome," says Keller.

Once they have overcome that problem, there are companies ready to move forward. Andreas Schirmer from the company LS9 in South San Francisco describes a unique strategy. LS9 has engineered a proprietary microbe to produce UltraClean™ diesel in a one-step process. They have discovered a way to exploit the pathway that microbes use to make energy-rich fatty acids for the synthesis of cell membranes and energy storage compounds, and divert them for their own purposes. Inside the fermentor, the microbes and feedstock sit in water, so the oil-like fuel compounds rise to the surface and can be easily collected, much more efficiently than the energy rich distillation process necessary to produce ethanol.

Schirmer says they are currently using sugar cane as a cost-effective option and estimates an 80 percent reduction in carbon footprint compared to petroleum-based fuels.

"It is a bridge feedstock. Once second generation feedstocks come online we will be able to convert production over to them quickly and achieve even greater reductions in greenhouse gas emissions," says Schirmer.

Beside ethanol and biodiesel, researchers are also looking at producing hydrogen from renewable resources. Donohue's lab is working with purple bacteria called Rhodobacter sphaeroides that use photosynthesis to produce hydrogen from a combination of cellulosic feedstocks and sunlight. The hydrogen can then converted to electricity using fuel cells that his lab is also developing. They have completed laboratory scale prototype "microbial batteries" using the bacteria and the fuel cells in a single enclosed system that, when exposed to sunlight, produces enough electrical current to power a laptop.

"This is just a look under the hood at the types of activities that are going on in the United States to take advantage of microbial activities and deploy them to create the next generation of fuels," says Donohue.

Jim Sliwa | EurekAlert!
Further information:
http://www.asmusa.org

More articles from Life Sciences:

nachricht Cells communicate in a dynamic code
19.02.2018 | California Institute of Technology

nachricht Studying mitosis' structure to understand the inside of cancer cells
19.02.2018 | Biophysical Society

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Contacting the molecular world through graphene nanoribbons

19.02.2018 | Materials Sciences

When Proteins Shake Hands

19.02.2018 | Materials Sciences

Cells communicate in a dynamic code

19.02.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>