Navigation Links
Team looks to the cow rumen for better biofuels enzymes

CHAMPAIGN, Ill. When it comes to breaking down plant matter and converting it to energy, the cow has it all figured out. Its digestive system allows it to eat more than 150 pounds of plant matter every day. Now researchers report that they have found dozens of previously unknown microbial enzymes in the bovine rumen the cow's primary grass-digestion chamber that contribute to the breakdown of switchgrass, a renewable biofuel energy source.

The study, in the journal Science, tackles a major barrier to the development of more affordable and environmentally sustainable biofuels. Rather than relying on the fermentation of simple sugars in food crops such as corn, beets or sugar cane (which is environmentally costly and threatens the food supply) researchers are looking for better ways to convert the leaves and stems of grasses or woody plants to liquid fuel. These "second-generation" biofuels ideally will be "carbon neutral," absorbing as much carbon dioxide from the atmosphere as is emitted in their processing and use.

But breaking down and releasing the energy in the plant cell wall is no easy task.

"The problem with second-generation biofuels is the problem of unlocking the soluble fermentable sugars that are in the plant cell wall," said University of Illinois animal sciences professor Roderick Mackie, an author on the study whose research into the microbial life of the bovine rumen set the stage for the new approach. "The cow's been doing that for millions of years. And we want to examine the mechanisms that the cow uses to find enzymes for application in the biofuels industry."

In previous studies beginning in 2008, Mackie and Washington State University professor Matthias Hess (then a postdoctoral researcher at the U.S. Department of Energy Joint Genome Institute in California) used a decades-old technique for studying ruminant nutrition. They placed small, mesh bags containing either milled alfalfa or switchgrass through a cannula (a permanent, surgically installed portal) into the cow rumen and examined the microbes that adhered to each plant type after two or three days. Visual and chemical analyses showed that microbes in the rumen were efficiently breaking down both types of plant matter, with a different community of microbes attacking each plant type.

This and later experiments proved that the technique could help scientists find the microbes in the cow rumen that were most efficient at degrading a particular type of plant matter, said Mackie, who is a professor in the U. of I. Institute for Genomic Biology.

In the new study, the researchers focused on switchgrass, a promising biofuels crop. After incubating the switchgrass in the rumen for 72 hours, researchers conducted a genomic analysis of all of the microbes that adhered to switchgrass. This "metagenomic" approach, led by Edward Rubin, of the DOE Joint Genome Institute and the Lawrence Berkeley National Laboratory, analyzed all the genes in all the microbes present in a sample, rather than one at a time. This gave a more accurate picture of the processes in the rumen that make plant degradation possible, Mackie said.

"Bacteria are microbes," he said. "They don't live alone. They live in consortia, and they all contribute to the functioning and the services provided."

Using a variety of techniques, the researchers sequenced and analyzed the total DNA in the sample, a huge undertaking that allowed them to identify 27,755 potential "carbohydrate-active" genes. They cloned some of these genes into bacteria, and successfully produced 90 proteins of interest. They found that 57 percent of these proteins demonstrated enzymatic activity against cellulosic plant material.

The researchers also were able to assemble the genomes of 15 previously "uncultured" (never before grown in a lab) microbes, said Hess, who is first author on the new study. Several techniques, including sequencing the genomes of individual cells and comparing those to the assembled genomes, validated this approach, he said.

These results suggest that the bovine rumen is one of the best microbial habitats to explore for sources of plant-degrading enzymes, the researchers reported.


Contact: Diana Yates, Life Sciences Editor
University of Illinois at Urbana-Champaign

Related biology news :

1. Using a childs own stem cells to repair their heart looks promising
2. Graphene and spintronics combo looks promising
3. The ecosystem engineer: Research looks at beavers role in river restoration
4. K-State research looks at pathogenic attacks on host plants
5. New center looks at how human systems function or fail
6. Interdisciplinary research looks at Charlottes green mystery
7. Tinnitus study looks for cure to ringing in the ears
8. LSU researcher looks for new ways to keep a dirty situation clean
9. From bark to bedside: Study looks at canine cancer genes, human health impact
10. IFT session looks at changes in dietary fat and heart disease paradigm
11. Study looks at gorillas, elephants and logging in Congo
Post Your Comments:
Related Image:
Team looks to the cow rumen for better biofuels enzymes
(Date:11/18/2015)... November 18, 2015 --> ... a new market report titled  Gesture Recognition Market - ... 2015 - 2021. According to the report, the global gesture recognition ... anticipated to reach US$29.1 bn by 2021, at a ... North America dominated the global gesture ...
(Date:11/17/2015)... 17, 2015 Pressure BioSciences, Inc. (OTCQB: PBIO) ... and sale of broadly enabling, pressure cycling technology ("PCT")-based ... today announced it has received gross proceeds of $745,000 ... Placement (the "Offering"), increasing the total amount raised to ... additional closings are expected in the near future. ...
(Date:11/12/2015)... --  Growing need for low-cost, easy to use, ... the way for use of biochemical sensors for ... clinical, agricultural, environmental, food and defense applications. Presently, ... applications, however, their adoption is increasing in agricultural, ... on improving product quality and growing need to ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... 25, 2015 2 nouvelles études permettent ... les différences entre les souches bactériennes retrouvées dans la ... des êtres humains . Ces recherches  ouvrent une nouvelle ... prise en charge efficace de l,un des problèmes ... chats .    --> 2 nouvelles études ...
(Date:11/25/2015)... and HOLLISTON, Mass. , Nov. 25, ... HART ), a biotechnology company developing bioengineered organ ... Jim McGorry will present at the LD Micro ... at 2:30 p.m. PT. The presentation will be webcast ... days. Management will also be available at the conference ...
(Date:11/25/2015)... 25, 2015 /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ:  AEZS; ... and prospects remain fundamentally strong and highlights the ... recently received DSMB recommendation to continue the ZoptEC ... of the final interim efficacy and safety data ... in men with heavily pretreated castration- and Taxane-resistant ...
(Date:11/25/2015)... , Nov. 25, 2015 Orexigen® Therapeutics, Inc. ... participate in a fireside chat discussion at the Piper ... York . The discussion is scheduled for Wednesday, ... .  A replay will be available for ... Stilwell  , Julie NormartVP, Corporate Communications and Business ...
Breaking Biology Technology: