|Van Cauwenberge, James|
|Boehm, Michael - OH STATE U,COLUMBUS|
Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 9, 2002
Publication Date: December 9, 2002
Citation: SCHISLER, D.A., VAN CAUWENBERGE, J.E., BOEHM, M.J. USDA-ARS OHIO STATE UNIVERSITY COOPERATIVE RESEARCH ON BIOLOGICALLY CONTROLLING FUSARIUM HEAD BLIGHT: 1. DISCOVERY AND SCALE-UP OF A FREEZE-DRYING PROTOCOL FOR BIOMASS OF ANTAGONIST CRYPTOCOCCUS NODAENSIS OH 182.9, NRRL-Y30201. NATIONAL FUSARIUM HEAD BLIGHT FORUM PROCEEDINGS. 2002. p. 115-118. Technical Abstract: Yeast antagonist Cryptococcus nodaensis OH 182.9, discovered in previous collaborative research, reduces Fusarium head blight (FHB) of wheat in greenhouse and field environments. Laboratory protocols were developed for scaling-up biomass production of this antagonist in 100-liter (L) fermentors, processing biomass using continuous flow centrifugation and storing the biomass as a frozen concentrated paste for subsequent field evaluation at 15 sites across the U.S. in 2001. The studies reported currently were initiated to evaluate whether biomass of OH 182.9 could be freeze-dried to enhance product stability while maintaining biocontrol efficacy. Adding turanose (a disaccharide) and melezitose (a trisaccharide) to liquid culture broth enhanced OH 182.9 survival initially and over time compared to six other cryoprotectants. Melezitose extended the shelf-life of OH 182.9 at 100-mM and 50-mM concentrations but was not effective at concentrations of 10 mM and lower. Adding 25 mM melezitose and 1% skim milk to OH 182.9 biomass before freeze-drying resulted in a dried product that lost nearly 1 log10 unit upon freeze-drying but then maintained constant colony-forming unit counts for five weeks. Further studies with freeze-drying and alternative drying methodologies should be conducted to optimize OH 182.9 product stability and efficacy.