Role of the mutualistic fungus in lignin degradation in the fungus-growing termite Macrotermes gilvus (Isoptera; Macrotermitinae)

In order to investigate the role of the mutualistic fungus, Termitomyces sp., in the fungus-growing termite, Macrotermes gilvus, we applied CP/MAS 13C NMR and selected proximate analyses to fungus comb of different ages and degrees of maturation. We found evidence that lignin degradation took place progressively in the fungus comb. In vitro digestibility of cellulose in old fungus comb, on which the termites feed, was approximately 3-fold higher than that in the fresh part. These results confirm the ‘lignin degradation hypothesis’ that the role of the mutualistic fungi is to degrade lignin and enhance the digestibility of cellulose for the termites, suggesting the ability of the termite–fungus association to make extremely efficient use of plant material.