2007 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.
Work continued on the development of production, stabilization and formulation processes for microsclerotia of M. terrestris (MT) for use as a biocontrol agent against the invasive, aquatic weed, hydrilla. Microsclerotia are a form of MT that survives drying and is capable, upon rehydration, of infecting and killing hydrilla. Over the past year, we have conducted 25 5-liter fermentations, and 15 100-liter fermentations with MT. These experiments focused on optimizing production, harvesting, or drying processes for microsclerotia of MT; and microsclerotia from these production runs were used to identify formulations that enhanced their biocontrol efficacy. Laboratory evaluation of microsclerotia survival after drying and their ability to produce spores after rehydration was conducted at the Agricultural Research Services (ARS) National Center for Agricultural Utilization Research (NCAUR). Bioassays and field trials against hydrilla were conducted by, and in collaboration with, the U.S. Army Corps of Engineers, Vicksburg, MS, and SePro Corporation, Whitakers, NC. These studies led to improvements in the production and harvesting processes for microsclerotia of MT and in formulations of MT microsclerotia that showed improved biocontrol efficacy against hydrilla.
The delivery of spores of the fungal biocontrol agent P. fumosoroseus (Pfr) for Formosan subterranean termite (coptotermes formosanus;FST) control in living trees requires the use of a foaming agent that fills the termite feeding galleries without killing Pfr. A biocompatible foaming agent composed of keratin, a major component of cattle hooves and chicken feathers, was identified and found to have foaming characteristics very similar to the chemical-based foam currently used to deliver chemical termite control agents. This biocompatible foaming agent will allow the non-chemical, bioinsecticidal fungus Pfr to be effectively used for FST control in living trees and has the potential for use in other biocontrol situations where a biocompatible carrier is needed.
Dried spore preparations of Pfr have shown excellent efficacy in infecting and killing the FST. Dry spores of Pfr survived 2-4 weeks under the temperature and humidity conditions found in termite nests and were compatible with wood chips often used in termite bait stations. These studies suggest that there is potential to use dried spores of Pfr to infect and kill the FST.
Insect pheromones can be used to control insects by disrupting mating. Improvements were made to a wax-based granule system for the release of insect pheromones for this purpose. Several new formulations were evaluated and shown to enhance the product’s performance. Pheromone release profiles were developed relative to the concentration of the pheromone, size of the wax bead, and ambient temperature during bead exposure. Improved wax beads showed improved physical stability in the field, a problem identified in previous field studies. Wax bead samples were field tested for insect control efficacy by Rutgers University and for residual integrity at NCAUR.
Biologically compatible foam for the delivery of microbial biocontrol agents. The delivery of fungal biocontrol agents for Formosan subterranean termite (FST) control requires the use of a foaming agent that fills the termite feeding galleries without killing the fungal biocontrol agent. A biocompatible foaming agent composed of keratin, a major component of cattle hooves and chicken feathers, was identified and found to have foaming characteristics very similar to the chemical-based foam currently used to deliver chemical termite control agents. This biocompatible foaming agent will allow the non-chemical, bioinsecticidal fungus P. fumosoroseus to be effectively used for FST control in living trees and has the potential for use in other biocontrol situations were a biocompatible carrier is needed. This research is conducted under National Program 304 Crop Protection and Quarantine; Component 5--Pest Control Technologies; Problem Statement 2: Efficient Production, Delivery, and Utilization of Beneficial Organisms Used in Biological Control; and National Program 306 Quality and Utilization of Agricultural Products; Component 1--Quality, Characterization, Preservation, and Enhancement; Problem Area 1d: Preservation and/or Enhancement of Quality and Marketability.
|Number of new CRADAs and MTAs||1|
|Number of active CRADAs and MTAs||2|
|Number of invention disclosures submitted||1|
|Number of patent applications filed||1|
|Number of non-peer reviewed presentations and proceedings||11|
|Number of newspaper articles and other presentations for non-science audiences||1|
Arthurs, S.P., Lacey, L.A., Behle, R.W. 2006. Evaluation of spray-dried lignin-based formulations and adjuvants as solar protectants for the granulovirus of the codling moth, Cydia pomonella (L). Journal of Invertebrate Pathology. 93: 88-95.
Prasongsuk, S., Berhow, M.A., Dunlap, C.A., Weisleder, D., Leathers, T.D., Eveleigh, D.E., Punnapayak, H. 2007. Pullulan production by tropical isolates of Aureobasidium pullulans. Journal of Industrial Microbiology and Biotechnology. 34(1):55-61.
Jackson, M.A. 2007. The biotechnology of producing and stabilizing living, microbial biological control agents for insect and weed control. In: Hou, C., editor. Biocatalysis and Biotechnology: Functional Foods and Industrial Products. Boca Ratan, FL: CRC Press. p. 533-543.
Boyette, C.D., Jackson, M.A., Bryson, C.T., Hoagland, R.E., Connick Jr, W.J., Daigle, D.J. 2006. Sesbania exaltata biocontrol with colletotrichum truncatum microsclerotia formulated in 'pesta' granules. Biocontrol - Online DOI 10.1007/s/10526-006-9031-7.
Shearer, J.F., Jackson, M.A. 2006. Liquid culture production of microsclerotia of Mycoleptodiscus terrestris: A potential biological control agent for the management of hydrilla. Biological Control. 38:298-306.