See the following recent article:
M. Bacci, M.M. Anversa and F.C. Pagnocca
"Cellulose degaradation by Leucocoprinus gongylophorus, the
fungus cultured by the leaf-cutting ant Atta sexdens
rubropilosa"
Antonie Van Leeuwenhoek International Journal of General and
Molecular Microbiology 67, 385-386 (1995).