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United States Department of Agriculture

Agricultural Research Service

Research Project: PRODUCTION, STABILIZATION, AND FORMULATION OF MICROBIAL AGENTS AND NATURAL PRODUCTS
2008 Annual Report


1a.Objectives (from AD-416)
Develop liquid culture methods for producing microbial biocontrol agents by optimizing the nutritional and environmental conditions during growth for the production of an appropriate microbial propagule with optimal biocontrol efficacy and storage stability. Develop novel formulation technologies for microbial biocontrol agents and natural products through the selection and application of innovative processes and ingredients that lead to improved efficacy, storage stability, field stability and product delivery.


1b.Approach (from AD-416)
Our research strategy will focus on developing liquid culture methods for producing microbial biocontrol agents by optimizing the nutritional and environmental conditions during growth for the production of an appropriate microbial propagule with optimal biocontrol efficacy and storage stability. Formulation-based solutions to critical problems related to biocontrol agent stability, efficacy, and application will be addressed by evaluating the impact of formulation ingredients and processes on the physical characteristics, biological activity, storage stability, and field efficacy of selected biocontrol agents.


3.Progress Report
Temperature tolerance and optimization of production and drying processes for microsclerotia of Mycoleptodiscus terrestris (MT) were studied. Higher aeration rates reduced fermentation times and increased yields of microclerotia. Growth temperatures between 26-30ºC were optimal for the formation of microsclerotia. Temperatures between 24-28ºC were optimal for the germination and conidia production by microsclerotia. Temperatures between 24-28ºC were optimal for germination and conidia production. MT did not germinate or grow at temperatures above 32ºC. Polymers were identified that improved the drying survival of MT. Experiments were initiated to evaluate the survival of MT propagules after fluidized bed drying and determine the potential of liquid formulations of MT for hydrilla control. A patent application was filed for the liquid culture production method for microsclerotia of M. anisopliae. We evaluated the survival of dried Paecilomyces fumosoroseus (Pfr) blastospores in oak sawdust under differing storage conditions. Dried spores of Pfr survived 2-4 weeks at temperatures typically found in termite nests. Pfr blastospores were mixed with red oak sawdust and stored under vacuum at 4ºC for 12 months with no loss in viability. There is potential to use dried spores of Pfr to infect and kill the Formosan subterranean termite. The fungal entomopathogen Metarhizium anisopliae formed microsclerotia in liquid culture. Microsclerotia survived air-drying (<5% moisture) with no loss in viability. Rehydration of air-dried microsclerotia granules resulted in hyphal and sporogenic germination. A patent application was filed for the liquid culture production method for microsclerotia of M. anisopliae. Microsclerotia preparations resulted in significant infection and mortality in larvae of the sugarbeet root maggot, Tetanops myopaeformis. This use of sclerotial bodies provides a novel approach for the control of soil-dwelling insects with M. anisopliae. This research is conducted under NP 304, Component 5 and NP 306, Component 1.


4.Accomplishments
1. MICROSCLEROTIA PRODUCTION BY THE INSECT-PATHOGEN METARHIZIUM ANISOPLIAE. The production of a soil-stable, infective propagule of M. anisopliae is needed for soil-dwelling insect control. Cultures of M. anisopliae formed microsclerotia, fungal propagules formed to survive adverse environmental conditions, in liquid culture. Microsclerotia preparations of M. anisopliae survived air-drying (<5% moisture) with no significant loss in viability and germinated hyphally and sporogenically when rehydrated in soil. Bioassays using air-dried microsclerotia preparations resulted in significant infection and mortality in larvae of the sugarbeet root maggot, Tetanops myopaeformis. This is the first report of the production of sclerotial bodies by an entomopathogenic fungus and provides a novel approach for the control of soil-dwelling insects with M. anisopliae. This research is conducted under NP 304, Component 5, Problem Statement 2; and NP 306, Component 1, Problem Area 1d.

2. WAX-BASED GRANULES FOR SLOW RELEASE PHEROMONE DELIVERY. Wax-based granules containing the oriental beetle’s sex pheromone provided a slow release of the pheromone while the beetles are active. This formulation will provide a non-toxic pest control solution for use in turfgrass environments. A lignin-based adjuvant formulation was developed to tank-mix with current commercial insect control products. The adjuvant requires water-soluble lignin and a divalent cation salt to crosslink the lignin. We developed a physical formulation of lignin granules that wet, disperse, and dissolve quickly. The tank-mixed cation-lignin adjuvant treatment of baculovirus applied to field plots provided benefits similar to lignin formulated treatments with residual activity for several days beyond unprotected virus treatments. This research is conducted under NP 304, Component 5, Problem Statement 2; and NP 306, Component 1, Problem Area 1d.


5.Significant Activities that Support Special Target Populations
None.


6.Technology Transfer

Number of Active CRADAs1
Number of the New MTAs (providing only)1
Number of Non-Peer Reviewed Presentations and Proceedings4
Number of Newspaper Articles and Other Presentations for Non-Science Audiences1
Number of Other Technology Transfer1

Review Publications
Behle, R.W., Hibbard, B.E., Cermak, S.C., Isbell, T.A. 2008. Examining cuphea as a potential host for western corn rootworm (Coleoptera: Chrysomelidae): larval development. Journal of Economic Entomology. 101(3):797-800.

Jackson, M.A., Payne, A.R. 2007. Evaluation of the desiccation tolerance of blastospores of Paecilomyces fumosoroseus (Deuteromycotina: Hyphomyces)using a lab-scale, air-drying chamber with controlled relative humidity. Biocontrol Science and Technology. 17(7):709-719.

Dunlap, C.A., Jackson, M.A., Wright, M.S. 2007. A foam formulation of paecilomyces fumosoroseus, an entomopathogenic biocontrol agent. Biocontrol Science and Technology. 17(7):709-719.

Last Modified: 12/27/2014
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