Reducing fertilizer use through beneficial microbe reactions

May 8, 2012 under CANR News

Janine Sherrier, professor in the Department of Plant and Soil Sciences at the University of Delaware, is part of a team that has been awarded $6.8 million from the National Science Foundation (NSF) to study the legume Medicago truncatula.

Sherrier leads one of four research groups participating in this project, which represents a collaborative effort between researchers at the Noble Foundation, the Boyce Thompson Institute at Cornell University, the University of Delaware, and the University of North Texas.

“The aim of this large project is to generate resources for the U.S. and international research communities. We will generate resources to help accelerate the transfer of fundamental laboratory research results into useful applications for crop production,” said Sherrier.

In past years, the NSF has supported projects to sequence the complete genomes of organisms, including M. truncatula. The resources generated by this new NSF grant will help researchers define the roles of all of the individual genes within the genome and to elucidate how they are important for legume growth.

“Legumes, such as beans and lentils, provide one third of the protein consumed as part of the human diet globally. Legumes also contribute fiber and micronutrients to the human diet and are utilized widely as forage crops for livestock,” said Sherrier.

M. truncatula has been selected as a research model to study the symbiotic relationships that are characteristic of legumes. Unlike many species of plants, legumes rely on interactions with rhizobia (naturally-occurring beneficial microbes) to supply them with nitrogen. Many crop plants are supplemented with industrially produced nitrogen fertilizer, and the synthesis of the fertilizer is an energy-intensive process.

“As much as four percent of the world’s natural gas is consumed in the production of nitrogen fertilizers, releasing carbon dioxide by-products into the atmosphere,” said Sherrier.

When nitrogen is not present at sufficient levels in the soil to support plant growth, legumes create a home for beneficial bacteria in their roots. The plant develops a novel root organ where bacteria can grow, multiply and enter the plant cell, and within the plant cells the bacteria convert atmospheric nitrogen into a fertilizer for the plant. This greatly reduces the amount of fertilizer and energy necessary to produce a successful crop, lowers production costs for farmers and reduces runoff of fertilizers into the groundwater.

The focus of Sherrier’s research program is on the protein-to-protein interactions that are necessary for such beneficial plant-bacteria relationships to occur.

“If the plant lacks a specific protein, then this can allow bacteria to enter the plant and simply take the sugar without producing anything in return. This would be detrimental for a crop,” she explained.

As part of the NSF-funded project, Sherrier’s team will also be developing and teaching a 4-H summer camp across Delaware to teach children about how different microbes are important for agriculture. Campers will participate in science-based activities, such as using microscopes and making yogurt. The camps will contribute to the development of future growers in all three counties.

Article by Jacob Crum

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UD’s Wommack part of $25 million USDA food supply safety study

February 21, 2012 under CANR News

K. Eric Wommack, professor of environmental microbiology in the Department of Plant and Soil Sciences at the University of Delaware, is part of a five-year, $25 million U.S. Department of Agriculture (USDA) study aimed at preventing potentially fatal illnesses linked to Shiga toxin-producing E. coli bacteria (STEC) in the nation’s food supply.

STEC poses a serious threat to the food supply, resulting in more than 265,000 infections in the United States each year.

The coast-to-coast study includes a team of 48 investigators from multiple universities and government agencies, with the University of Nebraska and Kansas State University as the lead institutions.

Wommack became involved with the project after serving on a USDA grant review panel with Jim Keen, the lead project director from the University of Nebraska, who had been studying STEC for a number of years and was putting together the project proposal.  “It was really just good fortune on my part to be lucky enough to be involved with the group,” said Wommack, adding that he has not previously worked with STEC but can potentially bring a new angle to the research through his experience in microbial ecology.

As a microbial ecologist, Wommack said he is “interested in all the microbes that make up communities of microbes.” He equated this to an environmental ecologist, only instead of looking at “all the plant species within the make-up of the forest or the grassland, I look at all the microbes that comprise a microbial community.”

For this study, Wommack will examine the microbial communities that form around STEC to see if there is a pattern that scientists can pinpoint. This would allow the researchers to trace non-toxic levels of STEC by determining the kinds of microbial communities where it is most likely to occur.

“It is difficult to detect STEC when it is at the non-poisonous levels, but it is still there and so my work may show that there are other microbes that just happen to occur alongside STEC but are a whole lot easier to find. It is not like (STEC) is the only bacteria in a cow, so we are interested in looking at the larger communities that surround the pathogenic organisms.”

Wommack also will try to understand the ecology of STEC on a fundamental level.  “Although it is an organism that is an awful pathogen and kills people,” Wommack explained, “it is also a microbe that is out there and it has to live in whatever environment it is found in, and so most everything we know about STEC is when it is making people sick. We don’t really know much about it other than that — meaning its place in the ecology of microbial communities.”

Wommack said he is excited to get started on this research project, anticipating that he may begin work as soon as March. “It is hard to argue against knowing more,” he said. “Knowing and understanding more about the biology and the ecology of the organism will ultimately help us to control its incidence in the food supply.”

About Prof. Wommack

K. Eric Wommack is a professor in UD’s Department of Plant and Soil Sciences in the College of Agriculture and Natural Resources.

He also has appointments in the Department of Biological Sciences in the College of Arts and Sciences and in the marine biology and biochemistry program in the College of Earth, Ocean, and Environment. His laboratory is based in the Delaware Biotechnology Institute.

Wommack received a doctorate in marine estuarine environmental sciences from the University of Maryland, a master’s degree in physiology from the University of St. Andrews in Scotland and a bachelor’s degree in economics from Emory University in Atlanta.

He is a member of the American Society for Microbiology, the American Society of Limnology and Oceanography and the International Society for Microbial Ecology.

Article by Adam Thomas

Photo by Evan Krape

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University’s Kniel, Everts join study of produce safety

December 9, 2011 under CANR News, Cooperative Extension

Researchers at the University of Delaware are participating in a project that is focused on increasing produce safety and delivering more trustworthy salad fixings.

Total funding for the University of Maryland-led project amounts to $9 million, with $5.4 million in contributions coming from the U.S. Department of Agriculture’s National Institute of Food and Agriculture and substantial industry funds.

The three-year study promises to be one of the most comprehensive studies of fresh produce safety ever conducted.

Produce safety has been a hot topic ever since 2006, when a deadly batch of spinach killed three people and sickened hundreds of Americans. The project will involve extensive testing and data collection by industry, supplemented by field experiments involving eight other university and federal laboratories around the country.

Kali Kniel, associate professor in UD’s Department of Animal and Food Sciences, and Kathryne Everts, professor and Cooperative Extension specialist in plant pathology at Maryland with a joint appointment at UD, are part of the University of Delaware team.

“Since the large outbreak of E. coli in 2006 which was traced back to spinach grown in the Salinas Valley of California, produce commodities have been under great scrutiny,” Kniel said of the project. “As we all know fresh fruits and vegetables are grown outside, which puts them at great risk for coming in contact with biological hazards like pathogenic bacteria and viruses. There are some processes that growers and packers can do to reduce the risk but the science is still not there to completely understand what those are. This project will help to resolve that for very important and ‘high-risk’ products, including leafy greens and tomatoes.”

Kniel explained the role that she and Everts will play in the study, saying, “Dr. Everts and I will be working with the farmers and packers to both develop metrics and to disseminate the science-based results of the project.  I am particularly looking forward to working with regional growers and packers to help them deal with the food safety challenges including increased biological testing and best practices for safe compost and water use.”

Robert Buchanan, a University of Maryland professor and director of its Center for Food Safety and Security Systems, is heading the research initiative.

In addition to UD and Maryland, other universities involved include Ohio State University, Rutgers University, the University of California Davis, the University of Florida and the University of Maryland Eastern Shore. The USDA and the Food and Drug Administration (FDA) will be involved in the research as well.

The initiative’s industry partners — representing more than 90 percent of the leafy greens and tomato production in the United States — will conduct about 200,000 separate tests during the project to measure the presence of pathogens.

“This project is very unique in that it has the support of the industry on a significant scale. We have a great team of scientists and great industry support,” Kniel said.

The research aims to create the scientific basis for detailed safe, hygienic practices in farming, packing, transporting and storing fresh produce.

The idea is to prevent water, air or ground sources of pathogen contamination by setting standards or benchmarks that can be applied in a variety of growing regions and countries.

The study will examine questions such as how far apart do you need to keep a lettuce patch from pigs or other farm animals to prevent bacterial contamination and what kinds of barriers are needed to prevent contaminated water from reaching crops?

Members of the research team said they believe the project will give regulators, farmers, packers and others along the supply chain the scientific and technological knowledge needed to develop and defend produce safety protocols, or “metrics” as the industry calls them.

At the production stage, the research will focus on air, water and other environmental factors related to potential contamination by pathogens; risks during harvesting, packing, and processing; as well as temperature and other handling concerns as produce moves to market.

Photos by Ambre Alexander

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Students battle rice blast disease with underground microbes

November 30, 2010 under CANR News

Rice is the most important grain consumed by humans, providing more than one-fifth of the calories sustaining the world’s population. By some estimates, however, global production of rice could feed an additional 60 million people, if it weren’t for rice blast disease, caused by the fungus Magnaporthe grisea.

This past summer, four students from the University of Delaware and two of its partner institutions in Delaware’s National Science Foundation EPSCoR program, Delaware State University and Delaware Technical and Community College, found themselves on the front lines of the battle to defeat rice blast.

Those battle lines have been drawn on opposite coasts of the United States, through a collaboration between scientists in Delaware and at the University of California at Davis, the land-grant institution of the UC system. The students therefore split their summer internship between laboratories in both states.

The project is led by Harsh Bais, professor in UD’s Department of Plant and Soil Sciences and the Delaware Biotechnology Institute, and is funded by the National Science Foundation.

The full article with photos can be viewed online on UDaily by clicking here.

Article courtesy of Beth Chajes, DENIN

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EPSCoR seed grants awarded for environmental research

January 7, 2010 under CANR News

The Delaware EPSCoR office has awarded three seed grants to investigators whose projects address environmental challenges in Delaware.  CANR faculty members among researchers awarded. 

Click here for the full story on UDaily.

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