Present address: Research Institute for Humanity and Nature, 335 Takashima-cho, Kamigyo-ku, Kyoto, 602–0878, Japan.
Differential role of symbiotic fungi in lignin degradation and food provision for fungus-growing termites (Macrotermitinae: Isoptera)
Article first published online: 23 APR 2003
Volume 17, Issue 2, pages 186–193, April 2003
How to Cite
Hyodo, F., Tayasu, I., Inoue, T., Azuma, J.-I., Kudo, T. and Abe, T. (2003), Differential role of symbiotic fungi in lignin degradation and food provision for fungus-growing termites (Macrotermitinae: Isoptera). Functional Ecology, 17: 186–193. doi: 10.1046/j.1365-2435.2003.00718.x
- Issue published online: 23 APR 2003
- Article first published online: 23 APR 2003
- Received 21 March 2002; revised 12 September 2002; accepted 30 September 2002
- Carbon stable isotope ratio;
- food provision;
- fungus-growing termite;
- lignin degradation;
- 1To investigate whether the role of symbiotic fungi in lignin degradation and food provision differs among fungus-growing termites (four species of Macrotermes, three species of Odontotermes, Hypotermes makhamensis, Ancistrotermes pakistanicus and Pseudacanthotermes militaris), the chemical composition of fungus combs of different ages and the chitinolytic activity in the gut of termites were analysed. In addition, the carbon stable isotope ratios (δ13C) in old combs, worker termite tissues and fungal nodules (aggregated conidia) were compared.
- 2In Macrotermes spp., the carbohydrate : lignin ratio of the combs increased with increased comb age, but it decreased or remained the same in Odontotermes spp., H. makhamensis, A. pakistanicus and P. militaris. In contrast, the chitin : carbohydrate ratio and ash content increased more over time in the combs of Odontotermes spp., H. makhamensis, A. pakistanicus and P. militaris than in the combs of Macrotermes spp.
- 3Chitinolytic activity in the gut of workers was higher in O. takensis, H. makhamensis and A. pakistanicus than in M. annandalei.
- 4In all species examined, the δ13C value increased in the sequence: old combs < termites < fungal nodules. Based on a two-source model of δ13C, the contribution of fungi to termite nutrition was considered higher in Odontotermes spp., H. makhamensis, A. pakistanicus and P. militaris than in Macrotermes spp.
- 5These results suggest that symbiotic fungi play different roles among fungus-growing termites. In Macrotermes spp., the main role of symbiotic fungi is to degrade lignin, so that the termites can utilize cellulose more efficiently, whereas in Odontotermes spp., H. makhamensis, A. pakistanicus and P. militaris, it is to serve as a food source.