title: Potential for Nitrogen Fixation in the Fungus-Growing Termite Symbiosis.
abstract: Termites host a gut microbiota of diverse and essential symbionts that enable specialization on dead plant material; an abundant, but nutritionally imbalanced food source. To supplement the severe shortage of dietary nitrogen (N), some termite species make use of diazotrophic bacteria to fix atmospheric nitrogen (N2). Fungus-growing termites (subfamily Macrotermitinae) host a fungal exosymbiont (genusTermitomyces) that provides digestive services and the main food source for the termites. This has been thought to obviate the need for N2-fixation by bacterial symbionts. Here, we challenge this notion by performing acetylene reduction assays of live colony material to show that N2fixation is present in two major genera (MacrotermesandOdontotermes) of fungus-growing termites. We compare and discuss fixation rates in relation to those obtained from other termites, and suggest avenues of research that may lead to a better understanding of N2fixation in fungus-growing and other termites.
authors.affiliation: Centre for Social Evolution, Section for Ecology and Evolution, Department of Biology, University of Copenhagen Copenhagen, Denmark.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Sapountzis
authors.affiliation: Centre for Social Evolution, Section for Ecology and Evolution, Department of Biology, University of Copenhagen Copenhagen, Denmark.
authors.forename: Jane
authors.initials: J
authors.lastname: de Verges
authors.affiliation: Section for Terrestrial Ecology, Department of Biology, University of Copenhagen Copenhagen, Denmark.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Rousk
authors.affiliation: Department of Plant Production and Soil Science, Forestry and Agricultural Biotechnology Institute, University of Pretoria Pretoria, South Africa.
authors.forename: Magdeleen
authors.initials: M
authors.lastname: Cilliers
authors.affiliation: Department of Plant Production and Soil Science, Forestry and Agricultural Biotechnology Institute, University of Pretoria Pretoria, South Africa.
authors.forename: Barend J
authors.initials: BJ
authors.lastname: Vorster
authors.affiliation: Centre for Social Evolution, Section for Ecology and Evolution, Department of Biology, University of Copenhagen Copenhagen, Denmark.
authors.forename: Michael
authors.initials: M
authors.lastname: Poulsen
keywords: Macrotermes; Odontotermes; macrotermitinae; nifH; nitrogenase; symbiosis