It Takes 'Guts' to Explore the Next Proteomics Frontier

Jul 16, 2010
Image from “The Termite Gut: Nature’s Microbial Bioreactor for Digesting Wood and Making Biofuels,” U.S. DOE Genomic Science Program.

(PhysOrg.com) -- In the quest to find new sources of biofuel, researchers are studying one of the most efficient bioreactors on earth: the termite. The same insect that causes distress to homeowners with its wood-consuming abilities also provides scientists with a fascinating area of study: the symbiotic microbial community that enables the termite to digest wood cellulose.

Researchers at Pacific Northwest National Laboratory analyzed the metaproteome—all proteins—of the bacterial community that lives in the hindgut paunch segment of the wood-feeding "higher" termite (Nasutitermes). Their goal: to define the contribution and sources of enzymes from the community to the insect.

Initially, they hoped this information would lead to identifying new and novel celluloses, which in turn could provide raw materials for the synthesis of . However, while such insights remain elusive, they still gained biological insights into the necessary associations of this symbiotic system from their analyses, thus advancing understanding of the microbial community function in the termite gut and eventually pointing to important interactions in the degradation of wood products.

This work represents an important advancement of community proteomics efforts that can impact studies of any microbial community. Community proteomics is emerging as the next proteomics frontier—where the precise genome of the organisms being studied is unknown. play important roles across the biosphere from carbon and nutrient cycling in the atmosphere to impacting and protecting human health.

Molecular snapshot of enzymes (illustrated as Enzyme Commission numbers) identified in the termite hindgut microbial community and their main processes. (PFOR EC:1.2.7.-)

Using mass spectrometry-based global proteomics strategies available through EMSL, the PNNL team identified 886 proteins, 197 of which are known to be enzymes. Using these enzymes, the researchers reconstructed complete . These pathways revealed such important functions as transport and metabolism, and assimilation, energy production, and amino acid synthesis. Perhaps of greatest significance was determining the high level of redundancy of a protein important to nitrogen fixation and the breakdown of glucose: pyruvate ferredoxin/flavodoxin oxidoreductase (PFOR EC: 1.2.7.-). It has been reported that Nasutitermes lacks measurable pyruvate dehydrogenase activity in its tissues; therefore, bacterial PFOR may be critical to making nitrogen and acetate available to the termite.

"Our observations could not have been developed without reconstructing known bacterial metabolic pathways, and placing these pathways in context to what is currently known about metabolic pathways in the termite host," said Dr. Kristin Burnum, a PNNL biochemist and first author of a manuscript that appears in The ISME Journal.

What's Next. Understanding the symbiotic relationship between the community and the termite is only the first step in the elucidation of cellulose degradation in the system. While this work suggests that the activity associated with these enzymes in the community may play more of a role in the symbiotic relationship between the hindgut microbial community and its termite host than activities related to cellulose degradation, these results create a framework for future studies on all insect-microbial community studies to explore new cellulose-degrading activities.

Explore further: Survey of salmonella species in Staten Island Zoo's snakes

More information: Burnum KE, SJ Callister, CD Nicora, SO Purvine P Hugenholtz, F Warnecke, RH Scheffrahn, RD Smith, and MS Lipton. 2010. "Proteome Insights into the Symbiotic Relationship between a Captive Colony of Nasustitermes corniger and its Hindgut Microbiome." The ISME Journal, advance online publication July 8, 2010, doi:10.1038/ismej.2010.97

Related Stories

Diuscovery in amber reveals ancient biology of termites

May 14, 2009

The analysis of a termite entombed for 100 million years in an ancient piece of amber has revealed the oldest example of "mutualism" ever discovered between an animal and microorganism, and also shows the ...

Revealing the metabolic activity of microbial communities

May 11, 2010

Microbial communities are performing important functions all around us - from the earth in our flowerpots to the human gut. Now researchers have developed a method for studying the metabolic functions of microbial ...

Recommended for you

Compound from soil microbe inhibits biofilm formation

12 hours ago

Researchers have shown that a known antibiotic and antifungal compound produced by a soil microbe can inhibit another species of microbe from forming biofilms—microbial mats that frequently are medically harmful—without ...

Researcher among best in protein modeling contests

15 hours ago

A Purdue University researcher ranks among the best in the world in bioinformatics competitions to predict protein structure, docking and function, making him a triple threat in the world of protein modeling.

Survey of salmonella species in Staten Island Zoo's snakes

16 hours ago

For humans, Salmonella is always bad news. The bacterial pathogen causes paratyphoid fever, gastroenteritis and typhoid. But for snakes, the bacteria aren't always bad news. Certain species of Salmonella are a natural part ...

A long-standing mystery in membrane traffic solved

Mar 27, 2015

In 2013, James E. Rothman, Randy W. Schekman, and Thomas C. Südhof won the Nobel Prize in Physiology or Medicine for their discoveries of molecular machineries for vesicle trafficking, a major transport ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.