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United States Department of Agriculture

Agricultural Research Service

Research Project: Biocontrol of Aflatoxin and Other Mycotoxins in Maize Using Non-toxigenic Strains of Aspergillus flavus

Location: Biological Control of Pests Research Unit

Title: Bioplastic made from corn starch as an effective biological delivery vehicle for control of agricultural pests

Authors
item Abbas, Hamed
item Accinelli, Cesare -

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 21, 2014
Publication Date: N/A

Technical Abstract: In recent years, increasing consumer sensitivity to environmental sustainability and favorable legislation has resulted in a rising demand for renewable and bio-based products, including biodegradable plastic. A recent market research report has projected a 15% annual increase in the demand of biodegradable plastic over the next five years. Currently 84% of world biodegradable plastic consumption is concentrated in Europe and North America, with the remaining 16% in Asia. Important Bioplastic manufacturers include US-based companies (Nature Works, Ceroplastic, Metabolic, DuPont, etc.) and European companies (BASF, Movement, etc.). Most of these products have been designed to directly replace existing petroleum-based plastic products (e.g., single-use disposable plates, shopping bags, household appliance accessories, agricultural mulching films, etc.). Bioplastic are produced from renewable sources (mainly corn) and have the major advantage of biodegradability, because environmental microbes can utilize the types of polymers found in Bioplastic as sources of nutrients for sustaining their growth. The innovation summarized here is different in that it redirects the basic concept: since bioplastics are able to sustain the growth of many microorganisms, why not use bioplastics as delivery/reservoir materials to sustain and deliver beneficial microorganisms? Aspergillus species produce aflatoxins that cause contamination of crops including peanuts, cotton, treenuts, and especially maize resulting in agronomic losses totaling millions of dollars annually. Several non-toxigenic A. flavus strains are able to reduce the amount of aflatoxin contaminating harvested field crops. Because of difficulties in storing these microbes in a viable state and in applying them to fields, several methods have been developed that enhance their effectiveness. Bioplastic granules of modified starch were used as carriers of non-toxigenic Aspergillus strains. The granules can be easily handled by current farm machinery. Granules applied to soil and to growing plants were shown to increase the population of non-toxigenic A. flavus in soil by an average of 88% and increased colonization of corn kernels by an average of 93% resulting in reduced aflatoxin contamination in harvested grain. In field trials in the Mississippi Delta and Italy from 2009 to 2012, aflatoxin levels were reduced an average of 70% to 80%, respectively. Bioplastic granules were also an effective delivery system for other biological control fungi. Damping off caused by Rhizoctonia solani and Pythium ultimum in horticultural crops such as tomatoes, impatiens and annual bluegrass was suppressed 80% to 90% by bioplastic granule formulations of Trichoderma virens and T. harzianum. There was no significant difference between the results when 1% or 10 % of bioplastic granules were amended in soil. This study demonstrates that bioplastic granule formulations have the potential to extend biocontrol technology to horticultural plant diseases, in addition to their demonstrated effectiveness in controlling aflatoxin in agronomic crops.

Last Modified: 7/31/2014
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