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United States Department of Agriculture

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THE ASPERGILLUS FLAVUS GENOMICS PROGRAM FOR SOLVING THE PROBLEM OF AFLATOXIN CONTAMINATION OF U.S. CROPS. The mission of the Food and Feed Safety Research Unit is to reduce and eliminate aflatoxin contamination of preharvest crops such as cotton and corn.  In order to devise strategies to control aflatoxin contamination through understanding the molecular mechanisms of aflatoxin biosynthesis in response to genetic, nutritional, and environmental signals, Aspergillus flavus genomic program including A. flavus Expressed Sequence Tags (EST) and A. flavus  microarray, has been completed.  A total of 19, 618 EST sequences, representing 7218 unique genes, has been deposited to NCBI GenBank Database (http://www.ncbi.nlm.nih.gov) for public access.  The functional classifications of the genes were assigned and released by Gene Index (http://www.tigr.org/tigr-scripts/tgi/T index.cgi?species=a_flavus).  A high density and high quality A. flavus microarray, containing 5002 unique genes including 31 aflatoxin pathway genes, has been constructed at The Institute for Genomic Research (TIGR) for functional studies of A. flavus biology.  Many putative genes involved in fungal virulence, development and aflatoxin formation were identified using the microarrays.  The collaborative project, A. flavus whole genome sequencing, is about to be completed.  There are at least 11,760 genes within the 36.2 Mega base pairs of A. flavus genome.  The genome sequence data will be released soon.  The availability of the A. flavus EST and microarrays will significantly enhance the ability in gene profiling and functional elucidation of genes that are potentially involved in aflatoxin formation. This program will have a great impact on the overall goal of our CRIS for eliminating aflatoxin contamination of crops.  [Contact: Dr. Jiujiang Yu,  504-286-4405,  email: jiuyu@srrc.ars.usda.gov.

TRANSFORMATION OF PLANTS WITH A CHLOROPEROXIDASE GENE TO ENHANCE DISEASE RESISTANCE. The invention provides a method of making plants resistant to plant pathogens by transformation of host cells with a bacterial gene encoding a nonheme haloperoxidase. Transgenic tobacco and cotton plants expressing a nonheme chloroperoxidase showed increase resistance to phytopathogens in vitro and in plants. The FFS scientists also demonstrated the ability in situ of the gene product to inhibit growth of fungal pathogens, including Aspergillus flavus in cottonseeds. Aflatoxin contamination of cottonseeds and other food and feed crops such as corn, peanuts and tree nuts poses a very high public health risk because of the extremely carcinogenic nature of the toxins. In addition, transgenic plants expressing the chloroperoxidase gene have shown efficacy against a number of other common plant pathogenic bacteria and fungi and should be of value in increasing crop yields and quality as well as reducing the need to apply chemical pesticides.
U.S. Patent (#6,703,540) [CONTACT: Dr. K. Rajasekaran (Raja) , 504-286-4482, FAX: 504-286-4419, email: krajah@srrc.ars.udsa.gov

FORMALDEHYDE-FREE DURABLE PRESS REAGENTS. Reagents now used by the textile industry to impart permanent press properties of cotton fabrics generally contain formaldehyde, a known mutagen. Exposure to formaldehyde vapors in the workplace is strictly controlled by regulatory agencies such as OSHA. Scientists at the Southern Regional Research Center have developed a new treatment that does not contain or release formaldehyde. Citric and malic acid are inexpensive, environmentally friendly compounds that become effective durable press reagents in the presence of suitable activators and catalysts. Two companies have already licensed the USDA patents for specific applications. The use of citric acid and USDA catalysts is also in comercial use for treatment of wood pulp for particular products requiring increased wet resilience and high moisture absorption, as in disposable diapers. Formaldehyde-free finishing treatments avoid the hidden costs of required periodic medical examinations, medical record keeping, continuing air analyses for formaldehyde, and increased ventilation needed in keeping formaldehyde levels within the legal limits. USDA patents covering polycarboxylic acid finishing technology include U. S. 4, 820, 307; 4, 936, 865; 4, 975 209 and 5, 221, 285. [CONTACT: Dr. Brian Condon, 504-286-4540, Fax 504-286-4271,email: bcondon@srrc.ars.usda.gov]

NEW MAGNESIUM PEROXIDE-BASED ANTIBACTERIAL AGENTS FOR COTTON AND COTTON BLENDS. Development of environmentally benign antibacterial agents for application to textiles and other materials is necessary and desirable because many of the older, effective antibacterial agents have been or are in the process of being removed from commercial use. Thus, scientists at ARS, SRRC in New Orleans developed new, environmentally benign antibacterial agents by the reaction of two readily available inorganic compounds: hydrogen peroxide and magnesium acetate tetrahydrate. The new antibacterial agents have been characterized by elemental and functional group analysis, infrared spectroscopy and thermal analysis. They are magnesium hydroperoxyacetate (MHPA) and magnesium dihydroperoxide (MDHP). These agents are water-insoluble, but dispersible and may be applied as dispersions to fabrics and affixed by conventional pad-cure methods. Aqueous dispersions of these agents are remarkably stable since they retain more than 75% of their peroxide activity after 6 months. Cotton and cotton/polyester blend fabrics containing the agents are antibacterial to representative gram-positive and gram-negative bacteria after curing. This activity is retained for 30 launderings on the blend fabrics and up to 50 launderings on cotton fabrics. US Patent 5,656,037. [Contact: Dr. Brian Condon, Phone 504-286-4540, Fax 504-286-4271, E-mail bcondon@srrc.ars.usda.gov]

DYEABLE DURABLE PRESS COTTON. Cotton fabrics with durable press properties show reduced dyeability. Thus they are not suitable for dyeing after garment manufacturing. Dyeing of fabric in garment form is used by the textile industry to control inventories and also to achieve quick response for specific color demands by customers. Researchers at the Southern Regional Research Center have developed new processes that allow durable press cotton fabrics to be dyed in the garment form with several classes of dyes. The anionically dyeable smooth drying crosslinked cottons are produced by chemical modification of the cellulosic textiles with a combination of a hydroxyalkylamine or hydroxyalkyl quaternary ammonium salt, a methylolamide crosslinking agent with appropriate metal salt catalyst, and a relatively low molecular weight polyethylene glycol (PEG). The resulting cotton textiles are dyeable with acid, direct and reactive dye classes even though the material is crosslinkd. This technology has potential for garment dyeing applications. It also is effective for producing special cross-dyed effects by treatment of cotton yarn with the appropriate formulation prior to weaving or by application to selective areas of a woven fabric prior to dyeing. U. S. Patent No. 5,298,584. Contact: Dr. Brian Condon, Phone 504-286-4540, FAX 504-286- 4271, E-mail bcondon@srrc.ars.usda.gov]

'PESTA' BIOCONTROL PRODUCTS MADE WITH AGRICULTURAL COMMODITIES. Numerous fungal and bacterial biocontrol agents can be matrix-encapsulated in granules ('Pesta') by a pasta-like process using wheat flour plus ingredients such as cereal grain flours/brans, clays, and water (or aqueous suspensions of the agents). The wheat flour, and other organic components, provide nutrients for rapid growth and colonization of the granules by the biocontrol agent inoculum. The process has been scaled up from the laboratory to the pilot plant (twin-screw extrusion and fluid bed drying). Some fungal bioherbicide products are stable for more than one year at 25° C, and efficacy has been demonstrated in field trials. U. S. Patent 5,074,902. [CONTACT: Dr. Margaret Lyn, 504-286-4363, e-mail: mlyn@srrc.ars.usda.gov]

FABRICS WITH MULTIFUNCTIONAL PROPERTIES. Development of new, high value added textile products based on natural fibers is necessary and desirable for the United States to be internationally competitive in advanced materials and fibers. Thus, scientists at the Southern Regional Research Center have developed science and technology that uses a textile coating to make fabrics respond to changes in temperature. Fabrics (cotton, blends and synthetics) treated with a class of chemical bound to the fibers (PEGs or polyethyleneglycols), absorb and store heat when the temperature rises and release it when the temperature is dropped. Treated fabrics also have many other improved properties: high liquid absorption, excellent soil release, resistance to static charge and pilling (balls of lint), wear, durable press and suppression of bacteria, fungi and body odors. This technology has attracted attention worldwide. Several hundred inquiries for numerous potential uses have been received. The patents have been licensed in the United States and abroad. U. S. Pat. 4,851,291 (July 25, 1989), U. S. Pat. 4,871,615 (Oct. 3, 1989), U. S. Pat. 4,908,238 (Mar. 13,1990) [CONTACT: Dr Brian Condon, 504-286-4540,email: bcondon@srrc.ars.usda.gov]

CORE-SPUN YARNS AND FABRICS. Although they are unequaled in wear comfort, 100% untreated cotton fabrics can shrink and wrinkle, unlike similar fabrics made from synthetic fibers, such as polyester. In order to improve the performance of all-cotton fabrics, they must be chemically treated to provide the desired properties such as durable-press, shrink resistance, or flame resistance. However, the application of chemical finishes generally results in substantial loss of fabric abrasion resistance, tensile and tear strengths, and, hence, durability. To minimize these problems, cotton fibers are usually intimately blended with suitable synthetic fibers (such as, polyester) which are much stronger than cotton and, once heat set, do not shrink and/or wrinkle. Unfortunately, some of the fabrics made of these different fiber blends still have certain deficiencies. For example, they frequently pill (make lint balls on fabric surfaces as they wear), do not provide the desired 100% cotton surface, do not provide satisfactory durable press features without special chemical finishing, and are also difficult to be made flame-retardant because of the presence of synthetic fibers. Research at the Southern Regional Research Center, New Orleans, Louisiana, has led to the development of special spinning technologies for producing unique "core-wrap yarns." As the name implies, a core-wrap yarn is composed of a central core of a finction-specific synthetic fiber and a sheath (wrap) of 100% cotton fibers. The core and sheath firmly adhere with each other and do not strip or slip during processing or usage. The core of the yarn provides excellent mechanical and functional properties, such as high strength, durable-press, dimensional stability, fire resistance/barrier, electrical conductivity, insulation, etc., while the sheath provides the traditional properties of "King" cotton. Thus, the fabrics made with these new core yarns, once they are simply heat set or, appropiately treated otherwise, exhibit satisfactory levels of permanent press, wrinkle recovery, dimensional stability (shrink resistance), tear strength, durability, fire resistance, and other desirable fabric performance characteristics. Research to develop and evaluate new commercial applications using different types of wrap and sheath materials is continuing under several national and international cooperative research agreements. Totally new concepts and approaches for producing even better staple core-wrap yarns at greatly increased productivity levels are under investigation. Relevant patents are: U. S. Pat. Nos. 4,976,096, 5,531,063, 4,961,306, 4,922,701, 4,541,231, 5,743 ,077, 5,802,826 Foreign Patents: Australia: No. 679, 339, Canada: NO. 2 183 226, China: No. ZL 95 1 921166.9, Europe : EU 0745151 (France, Germany, etc.), Israel: No. 112609, Japan: No. 3176926, Mexico: No. 190996 [CONTACT: Dr. Paul Sawhney, 504-286-4568, Fax: 504-286-4419, e mail: apsingh@srrc.ars.usda.gov]

GLUTEN-FREE RICE BREAD.   Economical rice bread products are needed for consumers with Celiac Sprue disease and other disorders that prevent consumption of gluten-containing grain (e.g. wheat) products.  Formulations for preparing rice bread using a home bread machine have been developed.  The prototype bread has desirable flavor and texture comparable to that of wheat bread.  A U.S. patent application has been filed.  The process will allow the consumer to readily and economically prepare gluten-free bread.  Ingredients cost $0.65/kg/loaf with marketing cost 2-3 times this cost.  [Contact:  Dr. Ranjit Kadan, 504-286-4332;  email: rkadan@srrc.ars.usda.gov]

EXCLUSION OF AFLATOXIN PRODUCING FUNGI FROM COTTONSEED. Using recently patented technologies, scientists were able to demonstrate biocompetitive exclusion of aflatoxin producing molds by naturally occurring non-toxic mold "cousins" in field-grown cottonseed. Application of these non-toxic mold cousins to cotton fields reduced aflatoxin contamination of cottonseed by 90%. Applications have been made to commercial fields and have been shown to have long-term influences on the aflatoxin producing potential of fungi in a treated area. The technology will be useful for reducing the vulnerability of crops to aflatoxin contamination. The presence of aflatoxins in cottonseed, corn, peanuts and other crops can prevent crop use for food and feed. U. S. Patent 5,294,442. [CONTACT: Dr. Peter J. Cotty, 520-626-5049, email: pjcotty@srrc.ars.usda.gov]

LOW-OIL UPTAKE RICE BATTER AND DONUTS.  Fried batters may enhance the sensory quality of the coated food, but they may also contain high amounts of oil and contribute to oil-related health problems such as obesity and heart disease.  Scientists discovered that gelatinized long grain rice flour and phosphorylated long grain rice starch esters can be effective in enhancing both the viscosity and oil lowering properties of rice flour batters. These batters when applied to chicken absorb up to 60% less oil than a traditional wheat-based batter.  Following an approach similar to that taken for the batter development, low oil-uptake rice donuts were developed.  The product formulated with long grain rice flour and pre-gelatinized long grain rice flour (30%) absorbed as much as 54% less oil than traditional wheat flour donuts.  U.S. Patent 6,224,921 (May 1, 2001).  [Contact:  Dr. Frederick Shih, 504-286-4354; email:fshih@srrc.ars.usda.gov]

TANDEM SPINNING. Today, the most common practice in textile manufacturing to produce a mostly-cotton fabric of improved functional performance is to intimately blend cotton with a suitable synthetic fiber during mechanical processing. However, even the intimate blend fabrics do not always exhibit all the desirable fabric properties, because the synthetic fibers also have certain disadvantages, particularly when they appear on the fabric surface. A few years ago, scientists at the Southern Regional Research Center developed new spinning technologies to form the so-called "core-wrap" yarns in which the core material usually is a strong synthetic fiber and the wrap/sheath is comprised of 100% cotton. Thus, the yarn core contributed to excellent mechanical and functional properties of the ultimate fabric and the cotton wrap provided the desirable fabric substrate and hence comfort characteristics. However, the ring spinning system, for which the newcore-wrap spinning technologies were originally developed, inherently has avery low rate of productivity, say, 15 to 20 yards a minute, which makes the system uneconomical for certain applications. To increase productivity of core-wrap spinning, we successfully developed a totally new concept of so-called Tandem Spinning. It is a totally integrated tandem spinning system in which the core component of the yarn is produced by air jet spinning and the wrap component is produced by friction spinning. The resulting yarn, which is continuously and uninterruptedly produced at a speed at least ten times greater than that of conventional ring spinning, is torque balanced, soft, and yet strong. U.S. Patent Nos. 5,743,077, 5,802,826 Foreign Patents: Australia: No. 679, 339, Canada: NO. 2 183 226, China: No. ZL 95 1 921166.9, Europe: EU 0745151 (France, Germany, etc.), Israel: No. 112609, Japan: No. 3176926, Mexico: No. 190996 [CONTACT: Dr. Paul Sawhney, 504-286-4568, Fax: 504-286-4419, E- mail: apsingh@srrc.ars.usda.gov]

METHOD FOR FORMING CORE/WRAP YARN: An earlier USDA-patented core-spinning process had certain design flaws which consequently exhibited a few operational difficulties and related yarn quality problems. Specifically, the process lacked an adequate control of the wrap fibers in the yarn formation zone and also did not permit the conventional, easy piecing or replenishing of a broken end, especially while the machine was running. Compared to the conventional spinning, the yarn-piecing procedure of the USDA process took a significantly more time and also adversely affected the yarn quality by way of forming an objectionably long yarn piecing or slub (defect). The research led to the following design modifications which eased the operational difficulties and minimized the related yarn quality problems: a) the yarn-forming bar was redesigned to have I) an inwardly-sloped surface on each side of its central groove to better guide and hence control the cotton wrap fibers and ii) a pointed open end to facilitate threading and replenishing of a broken yarn/end in the conventional manner; and b) designed a new rotatable/swingable yarn-forming device, which, along with its independently settable yarn guide, could be efficiently swung out of - and back in - the yarn path to repair and replenish a broken end in the traditional manner without generating a long slub or defect. This improvement in the core-spinning technology led to a considerable renewed interest from the industry. U.S. Patent Nos. 5,743,077, 5,802,826 Foreign Patents: Australia: No. 679, 339, Canada: NO. 2 183 226, China: No. ZL 95 1 921166.9, Europe: EU 0745151 (France, Germany, etc.), Israel: No. 112609, Japan: No. 3176926, Mexico: No. 190996 [CONTACT: Dr. Paul Sawhney, 504-286-4568, Fax: 504-286-4419, E-mail:apsingh@srrc.ars.usda.gov]

ACTIVATED NUTSHELL CARBONS FROM AGRICULTURAL WASTE. The invention relates to activated carbons made from nutshells which are used to effectively remove metals present at toxic concentrations in water and wastewater. Nutshells, including almond and pecan shells, are high volume, low value agricultural wastes that have limited metals adsorption properties. An activated carbon from nutshells has been developed in which the capacity to adsorb metals was increased five to ten times over nutshells in their normal or non-carbonized state. These carbons also adsorbed two to three times more metals than commercial carbons evaluated under identical experimental conditions. The conversion of nutshells to value-added, activated carbons for metals remediation of contaminated water represents an excellent use of low value agricultural waste. Nut shellers can find a value-added outlet for a by-product that normally gives them little or no profit. Adsorbent users from small businesses to large companies will appreciate a product that is potentially lower in cost and higher in metals adsorption than activated carbons currently available. A preliminary cost estimate to manufacture nutshell carbons is about $0.85/pound. This manufacturing cost assumes conversion of 13 ton/day of shells to 3.5 ton/day of activated carbon. Carbon production in the United States is more than 300 million pounds per year, and is expected to grow more than 4 percent annually. U. S. Patent 6,033,573, Issued March 7, 2000 [Contact Wayne E. Marshall,(504) 286-4356, Fax: (504) 286-4356, E-mail marshall@srrc.ars.usda.gov


Last Modified: 10/24/2006
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