California Ag Network

Tag: ARS

  • Genome to Phenome: ARS Research in Precision Agriculture

    How do you build a better dairy cow? Use a tool designed to study the human genome, of course.

    Working alongside international research partners in the Agricultural Genome to Phenome Initiative (AG2PI), Agricultural Research Service (ARS) scientists are using technology to meet the challenges of the increasing global population and ever-changing environmental stressors. The goal of AG2PI is to better understand how genetics and the environment together influence the performance of plants and animals. This is easier said than done because regional environmental differences can vary the results of seeds from the same plant.

    “We know that nature (genotype) and nurture (environment and management) are both important factors in agricultural production (phenotype),” said Caird Rexroad III, ARS national program leader for animal production and protection in Beltsville, MD. “We need to better understand exactly how they affect production to develop optimal production strategies that are tailored to the diversity of genetics and environments that make up U.S. and world agriculture.”

    To achieve this goal, AG2PI reaches across kingdoms (scientific classifications) to examine genome-to-phenome challenges. Scientists in the various specialties work together to identify and fill in similar research gaps, access advanced cyberinfrastructure, and share data and new technology, such as sensors, robotics, and imaging platforms.

    “AG2PI is a community of scientists who share a passion for agricultural research and developing technologies that improve our ability to produce a safe, abundant, healthy, and affordable food supply,” Rexroad said. “This platform is inclusive of many scientific disciplines that may not have interacted in the past, such as breeders, engineers, economists, social scientists, etc., and works by sharing ideas, providing trainings on state-of-the-art technologies, and enhancing communication and collaboration.”

    One example of how ARS scientists used AG2PI to avoid research “stovepipes” (the term used to describe how one group may isolate its information from other unrelated groups) involves the international research to improve dairy cattle.

    “The Genome-to-Phenome Initiative began for us in 2007,” said Curt Van Tassell, research geneticist at the ARS Animal Genomics and Improvements Laboratory in Beltsville. According to Van Tassell, the landmark study used existing technology from one scientific discipline and applied it to another; in this case, technology was developed for the human genome and adapted for use in the cow by designing a DNA chip to characterize the whole genome of the cow.

    “We worked closely with dairy genetics industry partners to implement genome-enabled genetic improvement with dramatic impact in the dairy industry,” Van Tassell said. “With the help of our partners, we revolutionized the world of genetic improvement in livestock in one fell swoop.”

    While AG2PI is not in itself a scientific project, it supports all agricultural research that will benefit farmers, ranchers, and consumers, Rexroad said. “Farmers and ranchers will have access to genetics and management practices that will increase yields, improve crop and animal health and well-being, increase production efficiency or product value, and improve sustainability in the production system,” he said.

    “AG2PI is all about agricultural research, and it is inclusive of many scientific disciplines, and that ties into the ARS goal of finding solutions to agricultural problems that affect Americans everyday from farm to table,” Rexroad said. – By Scott Elliott, USDA-ARS Office of Communications

  • Growers Refine Date Palm Irrigation with UCANR Research

    California’s $86 million date industry produces more than half of the nation’s dates. Most of the fruit is grown in the arid Coachella Valley. Despite efforts by growers to conserve water, data was lacking on date palms’ actual water use to refine the best irrigation management for the crop until a recent research project led by Ali Montazar, UC Cooperative Extension irrigation and water management advisor for Imperial and Riverside counties.

    New research provides data California date growers need to apply a more precise amount of irrigation water to meet the trees’ needs to produce a healthy crop (photo by Ali Montazar).

    “California dates are grown in the hottest and most arid climate in North America and require substantial amounts of water in order to bring a successful crop to fruition,” Albert Keck, Coachella Valley date grower and chairman of the California Date Commission, wrote in a letter of support for this project. “In addition, there is scant modern research specifically and technically focused on growing dates in North America.”

    Montazar said there is a lack of irrigation management information on date palms worldwide.

    “The information developed in this study is expected to have a worldwide impact,” he said.

    To determine the evapotranspiration rate and crop coefficients for California date palms, Montazar teamed up with scientists at UC Davis, California Department of Water Resources, USDA Agricultural Research Service, and USDA Salinity Laboratory.

    The experiment was carried out in six date orchards in the Coachella and Imperial valleys. The sites represent various soil types and conditions, irrigation management practices, canopy characteristics, and the most common date cultivars in the region.

    “The findings of the project indicate that there is considerable variability in date palm consumptive water use, both spatially and temporally,” Montazar said. In other words, the amount of water the trees use varies considerably depending on each site’s growing conditions.

    He estimated the water needs for date palms planted in different soil types in the low desert region.

    “Growers will be able to use the science-based information and tools developed by this project to determine their date palm water needs and optimize the efficiency of water and fertilizer use in their groves,” Montazar said.

    Fruit bags protect date from insect damage and dust and prevent the fruit from falling to the ground (photo by Ali Montazar).

    The peer-reviewed article “Determination of Actual Evapotranspiration and Crop Coefficients of California Date Palms Using the Residual of Energy Balance Approach” is published in the journal MDPI Waterat https://www.mdpi.com/2073-4441/12/8/2253.

    “With a large quantity of new date plantings in the region, coupled with increasingly limited water resources in the Colorado River Basin Watershed, the knowledge anticipated to be developed by this research project has the potential to yield large dividends through not only improved water use efficiency, but also best management practices and crop quality,” said Keck of the California Date Commission.

    Although the research focused on Coachella Valley dates, Montazar said the results are likely to be useful to growers who have orchards with similar varieties, irrigation practices, and canopy and soil features in other locations.

    Montazar’s co-authors are Robert Krueger of the USDA-ARS National Clonal Germplasm Repository for Citrus and Dates; Dennis Corwin of USDA-ARS U.S. Salinity Laboratory; Alireza Pourreza UC Cooperative Extension specialist based at UC Davis Department of Biological and Agricultural Engineering; Cayle Little of California Department of Water Resources; Sonia Rios, UC Cooperative Extension advisor in Riverside County; and Richard L. Snyder UC Cooperative Extension specialist emeritus in the UC Davis Department of Land, Air and Water Resources.

    The date palm irrigation project was funded by the CDFA Specialty Crop Block Grant Program. — By Pamela Kan-Rice, UCANR

  • Drink Your Peas, Please!

    USDA Agricultural Research Service (ARS) scientist and director of the Western Regional Research Center (Albany, CA), Tara McHugh and her team in the Healthy Processed Foods Research Unit are experts at solving food-manufacturing problems. Using cutting-edge processing technologies, they have helped numerous small businesses, such as Ripple Foods, turn ideas into products for the consumer.

    ARS is helping Ripple Foods optimize its current pea protein drying process to make it more efficient and to further improve its products. The company manufactures its own pea protein by processing yellow split peas into a liquid form and then isolating, purifying, and drying the protein. The pea protein is then made into non-dairy milks, protein shakes, half and half, ice cream, and other products.

    The drying step is necessary because producing this clean-tasting plant protein in a wet state comes with challenges: It’s difficult to transport, has a greater risk for microbial spoilage, and has handling issues, McHugh said.

    “It’s also expensive to ship all over the country, so we are working to optimize the drying process—looking at a way to dehydrate it so it can be rehydrated to save expenses,” she said. “The drying process also may even improve the quality and flavor of the final product.”

    Ripple Foods has a cooperative research and development agreement with ARS, which assists the company in data gathering and analysis on different aspects of its pea beverage. “Ripple’s mission is to make plant-based foods delicious,” said Aminah Johnston, a process engineer with the company. “We are always looking for ways to make our protein and products better. Our collaboration with ARS has been extremely helpful.”

    This kind of research not only supports small businesses and U.S. growers, but also reduces waste and increases consumption of healthy foods.—By Sandra Avant, formerly with USDA-ARS Office of Communications.

  • Using Satellites to Improve Sustainability, Yield

    Two of the nation’s great agricultural regions are the focus of new research that aims to head off emerging threats and improve sustainability.

    Scientists with the Agricultural Research Service (ARS) are joining colleagues to create and use artificial intelligence to help farmers in the Colorado River Basin and Salinas Valley, CA, improve their management of irrigation, fertilization, and pests. USDA’s National Institute of Food and Agriculture funded the University of California, Riverside-led project with a 5-year, $10 million grant.

    “This project will integrate multiple satellite and meteorological data sets to help farmers in the Southwestern United States,” said Ray Anderson, a research soil scientist with the ARS Agricultural Water Efficiency and Salinity Research Unit in Riverside. Anderson leads the ARS portion of the study, working with ARS scientists Todd Skaggs and Andrew French.

    ARS has three primary roles in the project: To calculate project area crop water use and anomalies with crop water use across the entire region; develop tools that help growers avoid salinity damage while minimizing the leaching of fertilizer; and to gather field data to validate satellite algorithms.

    Researchers will take advantage of advanced satellite technology to provide more frequent, detailed information to farmers than ever before. The plan is to integrate high-resolution commercial satellite data with established government satellite platforms and meteorological data.

    A major advance with this work will be the use of daily, high-resolution (12-foot) satellite imagery, Anderson said. Previously, data have only been available every 1-2 weeks at 60- to 100-foot resolution and were too infrequent or coarse to provide timely and actionable information to farmers.

    “By combining the new satellite data with artificial intelligence, we will be able to discover and create tools that will help farmers pinpoint areas that need better irrigation, nutrient, and pest management,” Anderson said.

    “One of the major advantages to this project is that the outputs – recommendations and highlights on a smartphone app – will be accessible to all farmers,” he said. “Previously, farmers had to pay for aircraft and specialized processing to get this level of imagery and detail. Soon, high resolution satellite imagery, machine learning, and cloud processing will be available to smaller producers in one easy-to-use tool. These algorithms will help farmers with their field scouting so that they can catch problems early, before significant yield reductions occur.”

    Agriculture in the Colorado River Basin and Salinas Valley employs more than 500,000 people and generates roughly $12 billion annually in revenue. Farmers in the regions grow fruits and vegetables that are shipped around the country all year round, particularly in winter.

    Water availability and use top the researchers’ priority list because prolonged drought has reduced agricultural water availability in the southwestern United States.

    “These valleys consume large amounts of irrigation water, but the amount and quality of irrigation water is decreasing,” Anderson said. “It is important to use existing supplies more efficiently and to protect water sources from nutrient and salinity contamination that can come from poor irrigation management.” — By Scott Elliott, USDA-ARS Office of Communications.

  • US Loses $44 Billion to Soil Erosion

    “Dirt cheap.” It’s an old saying, but hardly accurate. The fact is, the United States loses about $44 billion each year from soil erosion. The challenge is to keep that dirt where it is needed. Soil erosion is the detachment and movement of soil from one place to another by water or wind. Agricultural Research Service (ARS) scientists from around the country have long studied the problem and recently developed a coordinated strategic vision for ongoing ARS erosion research, including improved models to predict erosion and how to control it. Their work, the ARS Strategic Plan for Erosion, was published in the November/December issue of the Journal of Soil and Water Conservation.

    “ARS is the world leader in understanding and modeling erosion and has been since at least the 60’s,” said Marlen Eve, ARS deputy administrator for natural resources and sustainable agricultural systems. “Erosion mitigation research has been a core effort of ARS for decades and this strategic plan is an effort to modernize our models and create new ‘precision agriculture’ approaches to managing soils and mitigating erosion. This is a doubling down on our commitment. Our soil erosion research is helping lead America toward a more sustainable, food secure future.”

    The plan is the result of an ARS soil erosion modeling workshop held in the fall of 2019 and is a coordinated effort across several soil erosion modeling platforms, including the Rangeland Hydrology Erosion Model (RHEM). RHEM has been a focus of several ARS labs for nearly 30 years. In addition, the U.S. Department of the Interior’s Bureau of Land Management (BLM) and USDA’s Natural Resources Conservation Service (NRCS) rely on RHEM.

    The ARS team has also developed an RHEM PowerPoint tutorial for NRCS, BLM, and the governments of Kazakhstan and Jordan and provides training upon request to state and federal agencies.

    “The most vulnerable rangeland areas for soil movement are where annual precipitation is between 4 and 16 inches per year, which limits the soil moisture available to sustain plant growth,” said Mark Weltz, rangeland hydrologist with the ARS Great Basin Rangelands Research Unit in Reno, NV. Weltz was one of the authors of the ARS Strategic Plan for Erosion. With low plant density and minimal plant canopy and ground cover, these arid and semi-arid areas are prone to erosion from wind and water following wildfires, or from overgrazing and off-road vehicles.

    Typical consequences of erosion include reduced soil quality for plant growth; build-up of eroded sediment in riverbeds, harbors, and behind dams that must be removed to maintain safe passage and prevent dam over-topping; and transportation of salts and nutrients that reduce water quality, such as algae blooms that harm aquatic life. To get a picture of what extreme wind and water erosion can lead to, one has only to look at historical records of the Great Dust Bowl of the 1930s and national monuments, such as the Grand Canyon and the Badlands.

    “The subtle aspect to soil erosion is that it removes water-holding capacity that plants need to grow and restricts the types of plants that can grow on the site,” Weltz said. “Further, most plant nutrients are stored in the surface soil. Once lost, it may take centuries to recover. In certain situations, once soil erosion has occurred to sufficient depth the productivity of the site is forever lost.”

    Fortunately, there are things that can be done to mitigate or prevent erosion, and that’s where the ARS Strategic Plan for Soil Erosion comes in. – By Scott Elliott, USDA-ARS Office of Communications

  • Synergy between Biotech and Classical Control Tactics Rid U.S. of Invasive Pest

    Genetically engineered cotton and classical pest control tactics combined to rid the United States and Northern Mexico of a devastating pest, according to a new study by Agricultural Research Service (ARS) and University of Arizona (UofA) scientists published in the Proceedings of the National Academy of Sciences.

    For most of the past century, the pink bollworm was the major cotton pest in the Southwest. For decades, cotton growing in Arizona, California, Texas, and New Mexico was only possible because farmers sprayed pesticides an average of 12 times a year, nine specifically against pink bollworm. Some farmers sprayed as often as 25 times a year without reaching control. In 1990, pink bollworm cost cotton growers $48 million in Arizona alone.

    A coordinated and multitactical list of areawide and integrated pest management strategies were developed over the years in hopes of putting down this pest while replacing expensive and environmentally hazardous chemical pesticides, explained research entomologist Jeffrey Fabrick, one of the authors of the study. Fabrick is with the ARS-USDA Pest Management and Biocontrol Research Unit in Maricopa, Arizona.

    “By analyzing computer simulations and 21 years of field data from Arizona, we proved that genetically engineered cotton and release of billions of sterile pink bollworm moths acted synergistically to suppress this pest,” Fabrick said.

    Both the computer simulations and what was seen in the field from 2006 to 2010 showed neither of the two tactics would have worked if used alone, he added.

    “Collaboration among farmers and scientists from government, industry, and academia was essential for the remarkable success of the pink bollworm eradication program,” said Bruce Tabashnik, lead author of the study and regents professor in the UofA Department of Entomology.

    In the late 1960s and 1970s, ARS scientists first began powering up the fight against pink bollworm. They helped create the artificial pheromones that allowed precise tracking of the pest as well as the first synthetic diet and methods for raising sterile pink bollworm moths to disrupt mating. Releasing synthetic female sex pheromone in cotton fields also was used to confuse males and disrupt mating Another important tactic required farmers to plow down cotton residues after harvest to reduce overwintering survival of pink bollworm.

    Enter genetically modified Bt cotton in 1996. Bt cotton is engineered to produce one or more proteins from the bacterium Bacillus thuringiensis (Bt for short) that kills pink bollworm and other related caterpillar pests and are harmless to people and most other insects, unlike broad spectrum pesticides. Growing mostly Bt cotton knocked the pink bollworm population down by 90 percent in 10 years. At the same time, farmers continued employing other techniques.

    By 2006, for the first time, eradication became a practical reality. With an eye to finishing off pink bollworm, detailed cooperative plans were developed by a coalition that included cotton farmers, grower organizations, ARS researchers, USDA’s Animal and Plant Health Inspection Service (APHIS), the biotech industry, the Arizona Department of Agriculture, the Arizona Cotton Research and Protection Council, and UofA extension and research scientists. Many of these groups’ counterparts in Northern Mexico were also were also recruited.

    APHIS also scaled up production of sterile pink bollworm moths so that billions of them were unleashed by airplanes to overwhelm any field populations of the pest.

    Removal of pink bollworm saved U.S. cotton farmers $192 million from 2014 to 2019 alone, according to the study. Pink bollworm suppression has also facilitated integrated pest management for all other cotton pests. Overall, this reduced insecticide use by 82 percent, avoiding application of 25 million pounds of insecticides in Arizona alone during the past two decades. It improved the overall environment and brought back beneficial insects as the ecology returned to a more natural balance.

    The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $17 of economic impact.

  • ARS Research Prepares Farm Soil During Farming’s ‘Off-Season’

    It may be winter, but farmers don’t stop growing crops or preparing their soil for future planting – and scientists with the Agricultural Research Service (ARS) are there – with the farmers – to help.

    “Climate changes pose significant challenges for many cropping systems,” said Tom Sauer, supervisory soil scientist at the ARS National Laboratory for Agriculture and the Environment (NLAE) in Ames, IA. “Changes in management practices need to be carefully evaluated to build or enhance the resilience of different agroecosystems.”

    Researchers at NLAE are midway through a 5-year project, Managing Energy and Carbon Fluxes to Optimize Agroecosystem Productivity and Resilience, to investigate aspects of cover cropping and tillage on farm production efficiencies. The project also looks at agroforestry – tree windbreaks and silvopasture (mixing forestry, forage production, and grazing).

    “We have been tracking a variety of metrics for soil organic matter under cover cropping and reduced tillage,” said Peter O’Brien, research agronomist at NLAE. “We see some positive trends indicating that these practices may maintain soil carbon levels, in contrast to conventional systems that have declining levels of soil carbon.”

    Experiments at the USDA-ARS National Laboratory for Agriculture and the Environment in Ames Iowa are showing how cover crops like this radish can help protect the soil surface and improve soil health following the harvest of primary crops. (Photo by Katherine Kral-O’Brien)

    Cover cropping can help keep soil carbon in the ground and out of the atmosphere, thus significantly benefiting the environment, including water quality. Cover cropping encompasses a wide variety of practices. At the most basic level, O’Brien said, it is the practice of growing crops during the part of the year that the primary crops are not in the field, typically in the late fall and early spring.

    “While the concept is simple, there are a lot of different ways to implement a cover crop,” he said. “Farmers must make decisions about annual vs. overwintering cover crops, single-species vs. mixes, planting method, and how to terminate/manage overwintering cover crops to prepare for the next primary crop. Ultimately, factors like climate, soil type, crop rotations, and the farmer’s goals guide how cover crops are best implemented.”

    For example, in the corn-soybean rotations across the Midwest, O’Brien said the amount of time suitable for cover crop growth after primary crop harvest may be limited in comparison to other parts of the country. Consequently, some farmers may sow cover crops, especially cereal rye, into standing corn a week or two prior to harvest to lengthen the cover crop growing window.

    Cover cropping has many benefits for soil health that exceed just keeping carbon in the soil, such as reducing erosion, suppressing weeds, increasing soil biological activity, promoting soil physical quality, and providing pollinator habitat and/or high-quality forage for grazing.

    “Cover cropping can improve soil health in several ways, and healthy soils not only have the potential to increase crop yields, but they may also be more resilient to changing weather patterns,” O’Brien said. “Cover crops protect the soil surface from raindrop impact and excessive exposure to sunlight, both of which can break down soil aggregates and lead to erosion.”

    The ARS scientists are also showing that the non-cover cropping aspects of the project are just as essential to soil health.

    Cereal rye cover crop growing in fall after corn harvest. Scientists from USDA-ARS National Laboratory for Agriculture and the Environment in Ames Iowa are investigating how rye can protect the soil surface and reduce nitrogen losses through tile drainage systems. (Photo by Peter O’Brien)

    “The presence of trees either in long, linear rows (windbreaks) on the edge of fields or in widely-spaced rows (silvopasture) modify local microclimates by reducing wind speed, therefore lowering wind erosion, and providing shade that helps retain soil moisture,” Sauer said.

    Farmers can manage these agroforestry practices to reduce losses to their commercial crops from extreme events, particularly heat and water stress association with drought conditions. “Each of these practices can be managed for local conditions or climate trends to enhance their effectiveness in building agroecosystems that are more resistant to negative effects of climate extremes,” Sauer said.

    “This project contextualizes our goals of enhancing productivity and reducing environmental degradation,” O’Brien said. “All aspects of the research are geared towards understanding how our agroecosystems are responding to — and also contributing to — climate change, and it highlights the importance of finding management practices that promote resilience in changing conditions.” – By Scott Elliott, USDA-ARS Office of Communications.

  • Purple Sweetpotatoes for Thanksgiving, Christmas & More

    Bright-orange sweetpotatoes are a staple of many American Thanksgiving dinners and are often prepared with a traditional family recipe. But this year, why not start a new tradition with purple-fleshed sweetpotatoes?

    Both colors of sweetpotato are high in dietary fiber, vitamins, and minerals, but the purple varieties are also rich in health-beneficial antioxidants called anthocyanins and phenolic acids. Anthocyanins are plant pigments that make blueberries blue and cherries cherry-red, and the antioxidant activities in purple sweetpotatoes can be at similar levels to these antioxidant-rich fruits. Various studies have indicated that anthocyanins and phenolics from purple‐fleshed sweetpotatoes may have potential health benefits.

    A team of scientists from the Agricultural Research Service’s Food Science and Market Quality and Handling Research Unit in Raleigh, NC, collaborated with researchers at North Carolina State University to find ways to preserve purple-fleshed sweetpotatoes’ anthocyanin levels during processing into products like juice or natural colorants. Typically, heat is used during processing, but heat changes the flavor and prevents isolation and use of sweetpotato starch and fiber. But if heat is not used, then the flesh quickly browns due to the same enzymes that turn sliced apples brown.

    The scientists wanted to figure out a heat-free way to extract the juice and pigments directly from the raw purple sweetpotato. After those are extracted, what’s left is raw starch and fiber (pomace), each with its own uses and benefits.

    The team successfully used water containing a small amount of citric acid, a substance naturally present in citrus fruits, to inactivate the browning enzymes and preserve an appealing reddish-purple color in the fresh juice and pomace. Preserving the high anthocyanin content makes these products desirable as functional ingredients in beverages and other food products. This research can pave the way for sweetpotato processors to produce new, value-added products. The team published the study in the Journal of Food Science in 2019.—By Sue Kendall, USDA ARS Office of Communications.

  • New Bean Defeats Both Leafhoppers & Drought

    Agricultural Research Service (ARS) scientists in Puerto Rico have developed a new pinto bean germplasm that may increase a farmer’s yield, reduce production expenses, and help the environment.

    The new bean, called TARS-LH1, is resistant to two types of leafhopper – Empoasca fabea, the potato leafhopper, which can reduce common bean yield by 20 percent in temperate areas, and the tropical leafhopper, E. kraemeri, which can reduce yield by almost 80 percent in tropical areas.

    Further, TARS-LH1 is resistant to the bean common mosaic virus and drought stress. It also yields well and has good seed size, said Tim Porch, research geneticist at the ARS Tropical Agriculture Research Station in Mayagüez, Puerto Rico.

    Beans are among the most important crops grown worldwide, Porch said. “They are a nutrient-dense food and an excellent source of protein and fiber,” he said. “Eating more beans can potentially reduce the chances of heart disease, diabetes, and certain types of cancer.”

    In addition, the properties of the TARS-LH1 pinto bean offer economic benefits to farmers around the world by reducing pesticide input and increasing organic dry bean production. “Beans are primarily a crop of poor farmers worldwide, so reducing the amount of pesticide could increase farmer income and food security, and decrease the environmental impact of production.”

    Pinto beans are also a favorite of U.S. bean growers, accounting for about one-third of America’s bean crop.

    The new pinto bean variety has been released publicly in the form of germplasm, intended for use by plant breeders to incorporate traits of interest – in this case, leafhopper and drought resistance – into the varieties that farmers ultimately grow.

    The Porch research team tested the bean’s resistance to leafhopper in several locations, including the Michigan State University Crop and Soil Science Research Farm, in Haiti, and in Puerto Rico.

    It’s important to improve beans, Porch said, because pests and pathogens are constantly evolving and the climate is changing. “The next step will be to incorporate this resistance into other seed classes grown in the United States and into varieties grown by farmers around the world,” he said. Other potential improvements include heat tolerance and resistance to pathogens like rust and common bacterial blight. – By Scott Elliott, USDA-ARS Office of Communications

  • Compound from Soil Bacterium Gets Reboot as Antibiotics Super Booster

    USDA Agricultural Research Service (ARS) scientists and their collaborators continue garnering success in their tests of a compound that could bolster the potency of beta-lactam antibiotics, potentially reducing the dosages required and helping stave off resistance in the germs they’re meant to kill.

    According to Neil Price, a chemist with the ARS National Center for Agricultural Utilization Research (NCAUR) in Peoria, beta-lactams are a class of antibiotics widely used in human health, veterinary medicine and agriculture. Many are penicillin- and cephalosporin-based. However, some germs have developed resistance to the drugs, threatening their continued effectiveness in fighting infection and preventing illness. Indeed, the Centers for Disease Control and Prevention estimates antibiotic-resistant germs infect at least 2.8 million people in the United States each year. Of that total, 35,000 people die as a result.

    For his part, Price has partnered with a team of ARS scientists to bolster the potency of these antibiotics with a rebuilt version of a compound called tunicamycin. In nature, certain types of bacteria secrete tunicamycin in an act of chemical warfare to keep competing microbes from reaching choice resources. Unfortunately, tunicamycin also blocks the activity of a key protein in human and animal cells. To overcome this problem, the team reconfigured tunicamycin with a pair of hydrogen atoms, blunting its harm to human and animal cells but not germs.

    In the first round of laboratory trials, mixing the modified tunicamycin with oxacillin and other penicillin-based drugs made them 32 to 64 times more potent. Since then, the team has expanded the list of beta-lactam antibiotics that are synergized by one of two modified tunicamycins: TunR1 and TunR2.

    For example, 11 beta-lactams showed a two- to 256-fold increase in potency against Bacillus subtilis bacteria—including a Penicillin-G-resistant strain—when combined with TunR2 in microtiter plate tests. Additionally, Cefquinome (a fourth-generation cephalosporin-based antibiotic commonly used to treat bovine respiratory illness in cattle and ailments in swine) showed a 500-fold increase in potency against B. subtilis when combined with TunR2.

    “That synergistic effect is important for both overcoming pathogen resistance to Cefquinome and achieving a potential cost savings from needing 500 times less of it,” said Price, who co-authored a paper published in the August 2019 issue of the Journal of Antibiotics. ARS has also established a Material Transfer Research Agreement with Cayman Chemicals Company of Ann Arbor, Michigan, to scale-up the compounds’ production so that other research groups can evaluate their antibiotic-bolstering effects, especially in the biomedical field.

    The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.