But the presence of a fungal pathogen sometimes found in barley can result in a lethal toxin, called mycotoxin, in the animal feed. Now, Virginia Tech and Agricultural Research Service, USDA researchers have shown that newly developed transgenic yeast used during fermentation will help modify the mycotoxin in the animal feed product to a less toxic form. The research is published online in the September issue of Biotechnology for Biofuels.
New varieties of hulless winter barley have almost as much starch as corn and can be grown at times and in places where corn cannot, offering a flexible resource. When processed for ethanol, the versatile grain also provides a wholesome animal feed – unless contaminated. Of particular concern are trichothecene mycotoxins, which inhibit protein synthesis, an essential function of all tissues. The result can be immune system suppression and reproductive problems. Animals usually refuse to eat infected grain; otherwise death would be the eventual result.
"So we decided to see if the toxin could be modified to a less toxic product during fermentation," said Piyum A. Khatibi of Long Island, .N.Y., at that time a Ph.D. student in plant pathology, physiology, and weed science in the College of Agriculture and Life Sciences at Virginia Tech.
Khatibi was working on the problem of trichothecene contamination of grains with David Schmale, associate professor of food safety and plant biosecurity in the college, and plant breeder Carl Griffey, professor of crop and soil environmental science in the college. Griffey's barley team has developed resistant varieties of barley, as well as high starch varieties. The Virginia Tech barley team, made up of Wynse Brooks, research associate; Mark Vaughn, research specialist; and Greg Berger of Schulenburg, Tex., a Ph.D. student, all in crop and soil environmental sciences, has been collaborating with Kevin Hicks, team leader, and John Nghiem, chemical engineer, at the USDA Agricultural Research Service Sustainable Biofuels research team in Wyndmoor, Pa. – a partnership that began in 2001.
The Virginia Tech and USDA researchers decided to go after the most common mycotoxin in barley, deoxynivalenol (DON).
Previous research on a fungus (Fusarium graminearum) that produces DON in barley has identified several genes that convert trichothecenes to less toxic products. The research team selected two of these genes (TRI101 and TRI201), introduced them into a laboratory yeast strain (RW2802), and compared the results to commercial yeast that has been optimized to produce fuel ethanol. The researchers fermented four varieties of barley that Griffey's team created for biofuel use, hulless Eve and VA06H-25 and hulled Thoroughbred and Price.
Measurements of the resulting mash and animal feed revealed that DON had indeed been converted to a less toxic form (3ADON) during fermentation, with the transgenic yeast expressing either TRI101 or TRI201. The researchers wrote, "We found large reductions in DON via conversion (52.4 percent to 58.1 percent) during fermentation of the hulless barley line VA06H-25, which contained the highest levels of DON in its starting ground grain."
"But in all cases, using the yeast with the added genes resulted in decreased DON as it was converted to the less toxic form (3ADON)," said Khatibi.
"To our knowledge, this is the first detailed report of yeast expressing a DON modification enzyme during barley ethanol fermentation," said Schmale.
Khatibi said, "This study sets the foundation for modifying mycotoxins during fermentation and provides a model for future work when we find an enzyme that can actually destroy the toxin."
The research was supported by Schmale and Griffey's grants from the USDA, Virginia Agriculture Council, and Maryland Grain Producers Utilization Board.
The project was part of Khatibi's dissertation research. He graduated in August and is now a postdoctoral associate working in Schmale's lab continuing his work in mycotoxin detoxification.
The article, " Conversion of deoxynivalenol to 3-acetyldeoxynivalenol in barley derived fuel ethanol co-products with yeast expressing trichothecene 3-O-acetyltransferases," was written by Khatibi; Justin Montanti, engineering technician with the Sustainable Biofuels research team; Nghiem; Hicks; Berger; Brooks; Griffey; and Schmale.
The article is posted at http://www.biotechnologyforbiofuels.com/content/4/1/26
Learn more about the Schmale lab at http://www.ppws.vt.edu/~dschmale/
Susan Trulove | EurekAlert!
Tag it EASI – a new method for accurate protein analysis
19.06.2018 | Max-Planck-Institut für Biochemie
How to track and trace a protein: Nanosensors monitor intracellular deliveries
19.06.2018 | Universität Basel
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
19.06.2018 | Physics and Astronomy
19.06.2018 | Life Sciences
19.06.2018 | Physics and Astronomy