About the lab
We are a lab interested to termites, their phylogeny, microorganismal symbionts and ecology. We also work on behavior of termites, chemical communication and alarm communication.
Featured projects (3)
Termites are one of the main invertebrate decomposer organisms in tropical regions which is undoubtedly due to their association with both internal (endo-) and external (ecto-)symbiotic microorganisms. The microbial symbionts allow termites to break down the complex ligno-cellulose matrix of plant tissues and soil organic matter which enable termites to feed on nutrient poor but highly available organic matter. While the relationship between termites and endosymbionts has been widely studied, the understanding of the role of ectosymbionts is poor. We hypothesise that the latter may play a vital role in the successful development of termite functional groups and we aim to examine the relationships between termites, endosymbionts, ectosymbionts, and their food sources, which together with historical biogeography may explain the inconsistent intercontinental patterns of termite abundance. Mass sequencing of bacterial 16S rRNA and fungal ITS genes will be used followed by analyses of co-occurrence patterns to investigate the relationships between termites and their allied microorganisms. Our aim is to understand the inconsistent global termite abundance patterns by studying the relationships between termites and their internal and external symbiotic microorganisms. Mass sequencing of bacterial 16S rRNA and fungal ITS genes will be used followed by analyses of co-occurrence patterns.
Tropical forests, particularly in the Congo Basin, harbour a disproportionately large percentage of global species diversity, however, demand for agricultural land has caused rapid forest loss during last decades. Intensive farming is likely to cause habitat degradation in the long-term while sustainable farming may benefit both farmers and biodiversity. In this study, we examine soil degradation dynamics and biodiversity patterns under different land-use regimes in the Congo Basin, primary and secondary forest, cocoa agroforestry and field with annual crops. We will execute large scale ecological experiments to examine the contributions of key players in soil processes. We hypothesise that lower diversity of plant species may lead to soil exhaustion and termites are expected to be key decomposers that influence the composition of fungal and bacterial communities. We will use extracellular DNA from soil to compare the changes in tree and termite communities among the four land-use sites and formulate strategies for local sustainable farming. We aim to examine soil degradation dynamics and biodiversity patterns under different land-use regimes in the Congo Basin using pedological procedures and DNA sequencing for better understanding of the formation and exhaustion of soil. We will also formulate strategies for local sustainable farming.
In every warm region of the world, a huge proportion of biomass is converted to soil by termites. Besides this well-known fact, however, the global-scale contribution of termites to organic matter cycling has not been quantified. Our team will estimate the contributions of termites and their manifold environmental-engineering activities to some of the most fundamental processes of Earth’s ecosystems, specifically soil formation and carbon dioxide release. Going beyond the insect level, we will also use a series of experiments to estimate the contribution of the termites’ symbiotic microorganisms, and document the composition and function of these communities along a decomposition gradient. We aim to convey a comprehensive, global picture, by conducting the sampling in the Afrotropics (Cameroon), the Neotropics (French Guiana), the Indomalayan (south China) and the Australasian (Papua New Guinea) ecozones, and thus focusing on the most productive terrestrial biotopes on Earth. To discriminate and quantify the roles of termites, their allied microbial consortia, and environmental factors in organic matter recycling, we will deploy a hierarchical design of field and lab experiments. Our approaches comprise quantification of the production of plant matter and its decomposition by means of termite actions, metabarcoding of microbial communities in comparable environmental samples and standard sterile wood and soil baits with and without access of termites, transcriptomic approaches in environmental samples, cultivated microorganisms and termite guts, genome and metagenome sequencing of selected termites and their symbionts, as well as laboratory assays disentangling decomposition capacities of particular termites and microorganisms and influence of xenochemicals upon the degradation processes. The combined evidence will allow us to test four fundamental hypotheses, which are as follows: (A) Does pre-digestion microbial management support termite impact on biodegradation? (B) Do the interactions between termites and microbiota differ at two fundamental levels, and are endosymbionts inherited strictly vertically while ectosymbionts origin from the pool of local microbes? (C) Do specific termite-associated microbes or fungi, rather than environmental factors, facilitate the termite-driven degradation, and are the patterns of co-evolution evidenced at genome level? (D) Do selected xenochemicals, nutrients or biocides, support or suppress particular strains of microorganisms, and are the community changes reflected by enhanced or decreased decomposition rates?
Featured research (8)
Machadotermes is one of the basal Apicotermitinae genera, living in tropical West Africa. Old observations suggested the presence of a new gland, the intramandibular gland, in Machadotermes soldiers. Here, by combining micro-computed tomography, optical and electron microscopy, we showed that the gland exists in Machadotermes soldiers only as an active exocrine organ, consisting of numerous class III cells (bicellular units made of secretory and canal cells), within which the secretion is produced in rough endoplasmic reticulum, and modified and stored in Golgi apparatus. The final secretion is released out from the body through epicuticular canals running through the mandible cuticle to the exterior. We also studied three other Apicotermitinae, Indotermes, Duplidentitermes, and Jugositermes, in which this gland is absent. We speculate that the secretion of this gland may be used as a general protectant or antimicrobial agent. In addition, we observed that the frontal gland, a specific defensive organ in termites, is absent in Machadotermes soldiers while it is tiny in Indotermes soldiers and small in Duplidentitermes and Jugositermes soldiers. At last, we could also observe in all these species the labral, mandibular and labial glands, other exocrine glands present in all termite species studied so far.
Soil-feeding termites are abundant in tropical regions and play an important role in soil bioturbation and in the organic matter cycle. The Apicotermitinae are arguably the most diverse lineage of soil-feeding termites, but they are also the most understudied, probably because many species are soldierless, which makes identification difficult. Although the backbone of the termite phylogenetic tree is now well-resolved, the relationships among representatives of Apicotermitinae are still largely unknown. Here, we present phylogenetic trees inferred from 113 mitochondrial genomes of Apicotermitinae representative of the group diversity. Our analyses confirm the monophyly of the Apicotermitinae and the basal position of soldiered taxa, within which two lineages of soldierless species are nested. We describe two new monotypic genera, whose phylogenetic position appeared of special interest: Koutabatermes gen. n., lies on a long branch among soldiered taxa, and Apolemotermes gen. n., is sister to Adaiphrotermes. We resolved, with high support, the position of Asian genera as sister group of a clade comprising the monophyletic neotropical Anoplotermes-group and the small African clade including Adaiphrotermes and Apolemotermes gen. n.. Our trees cast light on the intergeneric and interspecific relationships within Apicotermitinae and reveal the polyphyly of several genera, including Ruptitermes, Astalotermes and Anoplotermes. Biogeographic reconstructions revealed two dispersal events out of Africa, one to the Oriental realm and one to the Neotropical realm. Overall, the timing of Apicotermitinae diversification and dispersal, following the Eocene–Oligocene boundary, matches that found for other groups of Neoisoptera. Nomenclatural acts are registered in ZooBank: http://zoobank.org/urn:lsid:zoobank.org:pub:CA1A21B6-573E-4855-8C88-372453C922F7.
The Neotropical family Serritermitidae is a monophyletic group of termites including two genera, Serritermes and Glossotermes, with different way-of-life, the former being the sole obligatory inquiline among “lower” termites, while the latter is a single-site nester feeding on dry rotten red wood. Like the most advanced termite’s family, the Termitidae, the Serritermitidae is an inner group of the paraphyletic family “Rhinotermitidae”, but unlike the Termitidae, it has been poorly studied so far. In this study, we bring new insights into the chemical ecology of this key taxon. We studied the trail-following pheromone of Serritermes serrifer and we identified (10Z,13Z)-nonadeca-10,13-dien-2-one as the only component of the trail-following pheromone of this termite species, as it is the case in Glossotermes, the other genus belonging to Serritermitidae. This result makes the family Serritermitidae clearly distinct from other Rhinotermitidae, such as the termites Psammotermes and Prorhinotermes, that use (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol and/or neocembrene as trail-following pheromones.
All termites have established a wide range of associations with symbiotic microbes in their guts. Some termite species are also associated with microbes that grow in their nests, but the prevalence of these associations remains largely unknown. Here, we studied the bacterial communities associated with the termites and galleries of three wood-feeding termite species by using 16S rRNA gene amplicon sequencing. We found that the compositions of bacterial communities among termite bodies, termite galleries, and control wood fragments devoid of termite activities differ in a species-specific manner. Termite galleries were enriched in bacterial operational taxonomic units (OTUs) belonging to Rhizobiales and Actinobacteria , which were often shared by several termite species. The abundance of several bacterial OTUs, such as Bacillus , Clostridium , Corynebacterium , and Staphylococcus , was reduced in termite galleries. Our results demonstrate that both termite guts and termite galleries harbor unique bacterial communities. IMPORTANCE As is the case for all ecosystem engineers, termites impact their habitat by their activities, potentially affecting bacterial communities. Here, we studied three wood-feeding termite species and found that they influence the composition of the bacterial communities in their surrounding environment. Termite activities have positive effects on Rhizobiales and Actinobacteria abundance and negative effects on the abundance of several ubiquitous genera, such as Bacillus , Clostridium , Corynebacterium , and Staphylococcus . Our results demonstrate that termite galleries harbor unique bacterial communities.
Termites are important plant biomass decomposers. Their digestive activity typically relies on pro-karyotes and protozoa present in their guts. In some cases, such as in fungus-growing termites, digestion also relies on ectosymbiosis with specific fungal taxa. To date, the mycobiome of termites has yet to be investigated in detail. We evaluated the specificity of whole-termite associated fungal communities in three wood-feeding termite species. We showed that the whole-termite fungal community spectra are stable over diverse environments, regardless of the host species, and differ markedly from the wood in which they nest. The core mycobiome is similar to that found in other ecologically related insects and consists of a narrow spectrum of common filamentous fungi and yeasts, known for their stress tolerance and their ability to decompose plant biomass. The observed patterns suggest that a number of fungal strains may have a symbiotic relationship with termites, and our results set the stage for future investigations into the interactions between fungi, termites, and their other gut microbiota.
- Faculty of Tropical Agro Sciences
About Jan Šobotník
- Termite research team is not an institution, but a state of mind. We are group of people sharing the passion to science, and to insects and lives. We are opened to all new collaborations, and while Research Gate shows an overview of our history and presence, you can find more news at FaceBook (facebook.com/termiteresearchteam). Let all beings be happy!