ARS | Publication request: PRODUCTION OF MICROSCLEROTIA OF THE BIOHERBICIDE MYCOLEPTODISCUS TERRESTRIS USING LIQUID CULTURE FERMENTATION

Submitted to: Society of Industrial Microbiology Annual Meeting
Publication Type: Abstract
Publication Acceptance Date: August 15, 2002
Publication Date: N/A

Technical Abstract: The endemic fungal pathogen Mycoleptodiscus terrestris (MT) has shown significant potential for use as a bioherbicide for management of the invasive aquatic weed hydrilla, Hydrilla verticillata. The goal of this study was the identification of nutritional and environmental conditions during liquid culture fermentation that would yield stable, effective bioherbicidal propagules of MT. Results from these studies demonstrated that, under appropriate nutritional conditions, aerated cultures of MT produced high concentrations of vegetative biomass that differentiated to form compact, hyphal aggregates that we have termed microsclerotia. Eight-day-old cultures yielded more than 5 x 10(6) melanized sclerotial propagules/liter with 50-90% of the microsclerotia surviving air-drying to less than 4% moisture. Bioassays showed that dried MT microsclerotia are capable of infecting and killing hydrilla. Furthermore, dried MT microsclerotia germinated both vegetatively and sporogenically upon rehydration, thus improving their potential to infect and kill hydrilla. These studies have demonstrated that liquid culture fermentation has potential for the commercial production of the bioherbicide Mycoleptodiscus terrestris.