Soil bacterium causes biofuel breakdown

Jan 13, 2014
Lignin, the tough woody polymer in the walls of plants, binds and protects cellulose that plants use for energy. Scientists at PNNL are part of a team that showed how a soil bacterium can degrade lignin, increasing its potential for use in biofuels.

(Phys.org) —Biofuels made from plant materials—also known as lignocellulosic biofuels—have promise as a source of sustainable alternative fuels thanks to soil bacterium known as Enterobacter lignolyticus SCF1. SCF1 degrades lignin and decomposes plant cell walls, allowing access to the cellulose sugars that plants use for energy. However, much remains to be learned about the processes and functions of SCF1 in breaking down lignin for use in biofuels.

But a study recently published by a team from the University of Massachusetts, the Joint BioEnergy Center, and Pacific Northwest National Laboratory reveals key insights about SCF1, including that it is the first soil bacterium to demonstrate the dual ability to degrade both as a and for breathing.

Lignocellulose is a renewable and abundant energy source in sufficient supply in the U.S. to make lignocellulosic biofuels sustainable and economically feasible. Furthermore, lignocellulose is not used for food, so it does not take food out of the supply chain. However, is one of the more difficult biomass materials to break down and transform for biofuel use. This work moves scientists one step farther toward that goal.

Using transcriptomics and proteomic techniques, the scientists observed increased growth of SCF1 grown on media amended with lignin compared to that grown on unamended media. They also observed that SCF1 degraded lignin in the absence of oxygen, improving the plant material's ability to produce biofuel.

Additionally, the multi-omics approach provided insights to lignin and its use as a terminal electron acceptor. This study also showed that SCF1 is able to degrade lignin both as food (assimilatory) and for breathing (dissimilatory)—the first to demonstrate this dual capability.

The researchers plan to grow SCF1 in the presence of bacterial communities adapted to switchgrass as the sole carbon source with and without poorly crystalline iron as an additional terminal electron acceptor. The plan is to do these experiments as a time course to test the hypothesis that iron supplements improved deconstruction of lignin through more or different enzymes.

Explore further: Lignin-feasting microbe holds promise for biofuels

More information: DeAngelis KM, D Sharma, R Varney, BA Simmons, NG Isern, LM Markillie, CD Nicora, AD Norbeck, RC Taylor, JT Aldrich, and EW Robinson. 2013. "Evidence Supporting Dissimilatory and Assimilatory Lignin Degradation in Enterobacter lignolyticus SCF1." Frontiers in Microbiology 4:280. DOI: 10.3389/fmicb.2013.00280

Related Stories

Lignin-feasting microbe holds promise for biofuels

Nov 13, 2013

Nature designed lignin, the tough woody polymer in the walls of plant cells, to bind and protect the cellulose sugars that plants use for energy. For this reason, lignin is a major challenge for those who ...

An enzyme to ease biofuel production

Aug 15, 2013

Limited availability of fossil fuels stimulates the search for different energy resources. The use of biofuels is one of the alternatives. Sugars derived from the grain of agricultural crops can be used to ...

Recommended for you

For resetting circadian rhythms, neural cooperation is key

2 hours ago

Fruit flies are pretty predictable when it comes to scheduling their days, with peaks of activity at dawn and dusk and rest times in between. Now, researchers reporting in the Cell Press journal Cell Reports on April 17th h ...

Rapid and accurate mRNA detection in plant tissues

3 hours ago

Gene expression is the process whereby the genetic information of DNA is used to manufacture functional products, such as proteins, which have numerous different functions in living organisms. Messenger RNA (mRNA) serves ...

For cells, internal stress leads to unique shapes

22 hours ago

From far away, the top of a leaf looks like one seamless surface; however, up close, that smooth exterior is actually made up of a patchwork of cells in a variety of shapes and sizes. Interested in how these ...

Adventurous bacteria

23 hours ago

To reproduce or to conquer the world? Surprisingly, bacteria also face this problem. Theoretical biophysicists at Ludwig-Maximilians-Universitaet (LMU) in Munich have now shown how these organisms should ...

User comments : 0

More news stories

Fear of the cuckoo mafia

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

Turning off depression in the brain

Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain's reward circuit and experimentally reversed it – but there's ...

Is Parkinson's an autoimmune disease?

The cause of neuronal death in Parkinson's disease is still unknown, but a new study proposes that neurons may be mistaken for foreign invaders and killed by the person's own immune system, similar to the ...