Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 4, 2004
Publication Date: August 4, 2004
Citation: Van Cauwenberge, J.E., Schisler, D.A., Slininger, P.J. 2004. Utilization of the osmolyte melezitose and its effect on the growth and freeze-drying tolerance of Cryptococcus nodaensis OH 182.9. Phytopathology (American Phytopathological Society Meeting Abstracts). 94(6):S106. Technical Abstract: Gibberella zeae is the primary causal agent of Fusarium head blight (FHB). Biocontrol agent Cryptococcus nodaensis OH 182.9 (NRRL Y-30216) reduces FHB severity. The trisaccharide melezitose enhances the survival of freeze-dried cells of yeast OH 182.9 stored at room temperature. To optimize the protective effect of melezitose and determine the extent of its utilization, melezitose (50 mM final concentration) was added to a semi-defined liquid medium (C:N 11, 14 g/L C) prior to, 24 h, 48 h, or 72 h after inoculation or at the time of culture harvest (96 h). Cell counts peaked at approximately 10(9) CFU/ml no later than 48 h after inoculation and generally were not influenced by the timing of the melezitose amendment. Freeze drying reduced cell counts from 10(9) CFU/ml to 10(5) CFU/ml for cultures without melezitose and 10(8) CFU/ml for cultures with melezitose, regardless of the timing of addition. By 22 days, cell counts of cultures freeze dried without melezitose had dropped further, while cell viability for cells freeze dried in the presence of melezitose remained unchanged. Results of melezitose utilization by OH 182.9 will be presented.