Unraveling solitary bee microbiota: ecology, importance during development and function

• Applicant: Professor Dr. Alexander Keller
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions ; Microbial Ecology and Applied Microbiology
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 279735434

Bees are considered to be very important agents for ecological networks and agricultural systems, mostly through their incommensurable pollination services. As recent studies demonstrated, it is however not only the abundance of bees that regulates ecosystem benefits, but also a diversity of pollinators is required to maintain effective pollination. As solitary bees contribute largely to overall pollination of natural and cultivated plants as diverse and effective pollinators, it is of high interest and goal of this study to gain knowledge about their effectiveness in recruiting offspringWe aim to identify natural microbiota of several bee species from different landscapes, relating it to ecological factors of importance and their origin in different nesting materials. This will be supplemented with a comprehensive pathological investigation of microbial agents found in diseased and dead solitary bee larvae. Further, we will apply experimental tests with bacterial suppression through antibiotic substances. We aim to identify changes in bee survivability and investigate the microbiota at different developmental stages of the larvae within a standardized setup. Lastly, we will analyse in detail the importance of bacteria in fermentation processes and antifungal activity. This is done by bioassays that monitor fungal growth/repression as well as changes in the pollen constitution and released nutrients in presence of bacteria isolated and cultivated from brood chambers. Further, we will investigate through shotgun sequencing the genomic properties of bacteria that show positive assays. These will be compared to those of known fermentation capabilities, i.e. lactic acid bacteria, and antifungal activity in Hymenoptera, e.g. Streptomyces, and studied for shared genes and pathways.The combined interpretation of these results will largely contribute to our general understanding of solitary bee development in relation to microbiotic interactions.

• DFG Programme: Research Grants