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

• Published in: Biocontrol science and technology Vol. 20; no. 5-6; pp. 465 - 474
• Main Authors: Dunlap, Christopher A, Schisler, David A
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.01.2010
• Subjects: biological control; biological control agents; Cryptococcus; Cryptococcus (Hyphomycetes); Cryptococcus flavescens; Cryptococcus nodaensis; desorption; desorption isotherm; desorption isotherms; disease control; drying; fluidized beds; fluidized-bed; fungal diseases of plants; Fusarium; Gibberella zeae; granules; inoculum; long term experiments; mortality; plant pathogenic fungi; scab diseases; shelf life; storage time; Triticum aestivum; viability; water content; wheat
• ISSN: 0958-3157; 1360-0478
• DOI: 10.1080/09583150903572377

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.