Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: 5/22/2003
Publication Date: 5/22/2003
Citation: Kargalioglu, Y., Jackson, M.A. 2003. Liquid culture fermentation production of microsclerotia of Mycoleptodiscus terrestris as a bioherbicide for control of Hydrilla verticillata. American Society for Microbiology.
Technical Abstract: Submerged cultures of Mycoleptodiscus terrestris (MT) produce microsclerotial (MS) propagules when grown under specific nutritional conditions. A liquid culture fermentation method was developed to produce infective MS of MT for control of Hydrilla verticillata, an aquatic weed. When basal media was supplemented with glucose (40-60 g/L) and with 45 g/L dried corn steep liquor (Solulys AST®) or Pharmamedia® as a nitrogen source, MT cultures produced high concentrations of melanized, infective MS. To evaluate how nitrogen sources effect MS formation in liquid culture and to develop a defined medium for future nutritional studies, various sources of inorganic and organic nitrogen were examined using a basal medium supplemented with glucose. Lysine, glutamate, arginine, and aspartate were evaluated for yield of MS, MS survival after drying, and sporulation. MS production in media supplemented with glutamate, arginine, or aspartate (1.6-2.1×103 MS/mL) was significantly lower than MS production by Pharmamedia®-supplemented cultures (3.3×103 MS/mL). Spore production by MS produced in glutamate or arginine-supplemented media were 1×106 and 5×106, respectively, and lower than spore production by MS produced in Pharmamedia®-supplemented media (7.5×103 spores/gram biomass). In all amino acid supplemented media, MS survival after drying was lower compared to MS produced in Pharmamedia®-supplemented cultures (>70% germination). Inorganic nitrogen sources tested include ammonium sulfate [(NH4)2SO4], ammonium chloride (NH4CL) and sodium nitrate (NaNO3). Among these inorganic nitrogen sources, [(NH4)2SO4] showed the highest yield of MS (2.4×103 MS/mL) and microsclerotia sporulation (1.5×107 spores/g biomass).