Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 12/4/2008
Publication Date: 12/8/2008
Citation: Schisler, D.A., Boehm, M.J., Paul, P., Slininger, P.J. 2008. Evaluation of Prototype Commercial Media for the Production of Fusarium Head Blight Antagonist Cryptococcus flavescens OH 182.9. In: Canty, S.M., Walton, E., Clark, A., Ellis, D., Mundell, J., VanSanford, D.A., editors. National Fusarium Head Blight Forum Proceedings, December 2-4, 2008, Indianapolis, IN. pp. 60-63.
Technical Abstract: Using biological control as part of the integrated management of Fusarium head blight (FHB) is understudied yet has considerable potential for significantly contributing to the reduction of FHB and deoxynivalenol (DON) in wheat. However, the development of a cost-effective, commercially feasible liquid culture medium for producing Cryptococcus flavescens OH 182.9 is a prerequisite step in the development of a commercial product for use in the integrated management of FHB. Three media were developed that utilized inexpensive, industrial grade sources of carbon and nitrogen and then compared with a laboratory grade medium for equivalence in producing high quantities of efficacious inoculum of strain OH 182.9. In shake flask production, a medium with an industrial source of a casein protein digest as a major carbon and nitrogen source produced a statistically similar maximum number of cells to that of the laboratory-grade medium (~2.6 x 10E+8 colony forming units/ml) while two media containing differing cotton seed-based protein sources supported less cell growth (~1.7 x 10E+8 cfu/ml). In bench top fermentors, the laboratory-grade medium supported greater growth than any of the industrial grade media (~5.4 x 10E+8 versus ~3.5 x 10E+8 cfu/ml, respectively). Regardless of production medium or the cell production vessel, OH 182.9 cells were similar in efficacy in reducing FHB severity in greenhouse tests (~20% and ~10% reduction for shake flask- versus fermentor-produced cells, respectively). Cells produced in the industrial casein protein digest medium and laboratory-grade medium did not differ in efficacy when field tested in two states. Current work on isolating variants of OH 182.9 with enhanced efficacy may require adjustments of the Hy-Case medium to meet the altered nutritional requirements of improved OH 182.9 strains.