Control and possible applications of a novel carrot-spoilage basidiomycete, Fibulorhizoctonia psychrophila

A novel cold-tolerant fungus, Fibulorhizoctonia psychrophila, was isolated from a refrigerated carrot storage facility and identified as an anamorph of Athelia, often classified in Rhizoctonia s.l. Growth of this fungus was observed between 0 and 20 degrees C with an optimum at 9-12 degrees C, while incubation of mycelium grown at 15-32 degrees C resulted in absence of growth even after the fungus was transferred back to 15 degrees C. Growth was inhibited in the presence of the antifungals sorbic acid or natamycin, in particular when the fungus was incubated at 18 degrees C. F. psychrophila produces polysaccharide degrading enzymes that, when compared to enzymes from the ascomycete fungus Aspergillus niger, retain a larger proportion of their activity at lower temperatures. This indicates that F. psychrophila could be used as a source for novel industrial enzymes that are active at 4-15 degrees C.