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Fluidized-bed drying and storage stability of Cryptococcus flavescens OH 182.9, a biocontrol agent of Fusarium head blight

Dunlap, Christopher A., Schisler, David A.
Biocontrol science and technology 2010 v.20 no.5-6 pp. 465
water content, Triticum aestivum, wheat, fungal diseases of plants, scab diseases, Gibberella zeae, plant pathogenic fungi, disease control, biological control, Cryptococcus (Hyphomycetes), inoculum, drying, granules, fluidized beds, biological control agents, storage time, shelf life, viability, mortality, long term experiments, desorption
A method to produce dried granules of Cryptococcus flavescens (formerly Cryptococcus nodaensis) OH 182.9 was developed and the granules evaluated for storage stability. Small spherical granules were produced and dried using a fluidized-bed dryer. A drying and survival curve was produced for the process of fluidized-bed drying at 30°C. The granules were dried to different moisture contents (4, 7, 9 and 12%) and evaluated for storage stability at 4°C for up to a year. These different moisture contents granules had the following respective water activities (0.22, 0.38, 0.47 and 0.57 a w). The results show the storage stability varied significantly across this moisture content range. The 9% moisture content sample had the best short-term stability (up to 4 months), while 4% moisture content had the best long-term survival (1 year). A desorption isotherm of C. flavescens was determined and modeled. The results of the storage stability and drying studies are interpreted in context of the desorption isotherm.