Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: August 13, 2003
Publication Date: June 20, 2003
Citation: Van Cauwenberge, J.E., Schisler, D.A., Palmquist, D.E., Slininger, P.J. The effect of osmolyte and freeze-drying on the efficacy of Enterobacter cloacae S11:T07 (NRRL 21050) against fusarium dry rot [abstract]. Phytopathology (American Phytopathological Society Meeting Abstracts). 93(6):S86. Technical Abstract: Giberella pulicaris is the causative agent of dry rot in stored potato tubers. Enterobacter cloacae S11:T:07 (NRRL 21050) is a proven antagonist against G. pulicaris. One concern in using S11:T:07 is shelf-life after biomass production. Freeze-drying biomass in the presence of osmolytes has been tested as a method for extending shelf-life. Turanose and arginine were shown to enhance the shelf-life of freeze-dried cell populations over time. In the present study, 100 mM turanose or arginine was added to a semi-defined medium that was inoculated with S11:T:07, harvested after 96 h and freeze-dried. Dried cells were stored at room temperature over 21 days. Efficacy testing and cell survival was evaluated periodically. S11:T:07 cells survived freeze-drying better when grown with turanose (-0.7 log units) than with arginine (-1.6 log units) or no osmolyte (-1.6 log units). Over a 21-day testing period, cells grown in the turanose medium showed superior survival of freeze-drying and reduced dry rot by 34% p<0.05.