Improved test can screen fungal pests for biofuel sources

Feb 12, 2009 By Sarah Perdue
Improved test can screen fungal pests for biofuel sources
Fungal extracts were added to a 96-well plate containing DNS, which changes color in the presence of cellulose breakdown products. The darker wells indicate extracts that broke down more cellulose; the lighter wells indicate extracts with little or no cellulose breakdown.

(PhysOrg.com) -- Those pesky fungi that wreak havoc on such important crops as corn and wheat just might be the key to low-cost biofuel production, report Cornell researchers who have improved a method to screen hundreds of fungal species rapidly to find ones that can most efficiently produce biofuels.

A report about their method is available online and will be published in a forthcoming issue of the journal Biotechnology and Bioengineering.

To make ethanol from plants, complex cellulose molecules in plant cell walls need to be broken down into simple sugars that are then fermented into ethanol. Plant pathogenic fungi have evolved to quickly and efficiently break down cell walls as they infect plants, making them an untapped resource in the search for cheap bioethanol, said Marie Donnelly, a graduate student in biological and environmental engineering and a co-lead author of the study.

This study is an important early step in identifying biofuel sources from agricultural plant waste, said Cornell plant pathologist and adjunct professor Donna Gibson and senior author of the paper. Current bioethanol production is too inefficient to be cost-effective, Donnelly added. Also, most bioethanol is derived from feed corn, which has made corn more expensive due to an increase in demand.

"We were looking for fungi that most efficiently break down nonfood plant materials, such as switchgrass and crop residues," she said.

The researchers extracted cellulose-degrading enzymes, or cellulases, from four fungal species. They tested the ability of the extracts to break down cellulose sources, from pure cellulose to plants themselves.

"Until recently, most research has focused on just cellulose degradation, but the plant cell wall is more complicated than pure cellulose," said Brian King, a graduate student in plant pathology and plant-microbe biology and also a co-lead author. "We're hoping to identify enzymes that are more effective on plant material than the current industrial enzymes."

Current methods assess how well fungal extracts degrade plant material by adding a chemical that changes color in the presence of the products derived from cellulose breaking down. The more degradation, the more intense the color change. The researchers greatly increased the rate of screening by using 96-well plates to perform the reactions; rather than putting each extract in an individual tube, they handled 96 samples in one 3-by-5-inch plastic dish. "We can collect data from 10,000 samples in a week," said King.

The rapid screening was first developed on a small scale to optimize the technique for large sample numbers.

"Before we can screen these thousands of isolates, we had to have a standardized methodology that we hope will capture the potential of these fungi," said Gibson. King is currently using this technology to screen dozens more fungi in an effort to identify the best species, or combination of species, for degrading a variety of plant materials.

Other researchers in the study include Gary Bergstrom, professor of plant pathology and plant-microbe interactions, and Larry Walker, professor of biological and environmental engineering.

The study was supported in part by Cornell, the U.S. Department of Agriculture -- Agriculture Research Service, and the New York State Foundation for Science, Technology and Innovation.

Provided by Cornell University

Explore further: Scientists target mess from Christmas tree needles

add to favorites email to friend print save as pdf

Related Stories

New protein probes find enzymes for biofuel production

Feb 06, 2013

New protein probes are now helping scientists find the best biomass-to-biofuel production enzymes that nature has to offer. Turning biomass into biofuel hinges on the breakdown of the energy-rich primary ...

Algae can draw energy from other plants

Nov 20, 2012

Flowers need water and light to grow. Even children learn that plants use sunlight to gather energy from earth and water. Members of Professor Dr. Olaf Kruse's biological research team at Bielefeld University ...

Recommended for you

Scientists target mess from Christmas tree needles

10 hours ago

The presents are unwrapped. The children's shrieks of delight are just a memory. Now it's time for another Yuletide tradition: cleaning up the needles that are falling off your Christmas tree.

Top Japan lab dismisses ground-breaking stem cell study

17 hours ago

Japan's top research institute on Friday hammered the final nail in the coffin of what was once billed as a ground-breaking stem cell study, dismissing it as flawed and saying the work could have been fabricated.

Research sheds light on what causes cells to divide

Dec 24, 2014

When a rapidly-growing cell divides into two smaller cells, what triggers the split? Is it the size the growing cell eventually reaches? Or is the real trigger the time period over which the cell keeps growing ...

Locking mechanism found for 'scissors' that cut DNA

Dec 24, 2014

Researchers at Johns Hopkins have discovered what keeps an enzyme from becoming overzealous in its clipping of DNA. Since controlled clipping is required for the production of specialized immune system proteins, ...

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.