Bacterial symbionts – Department of Biology - University of Copenhagen

Social Evolution > CSE Research > Model Organisms > Bacterial symbionts

It is becoming increasingly clear that a significant part of animal wellbeing depends on having the right communities of gut bacteria. CSE therefore has research programs that investigate the composition and diversity of the gut microbiomes of both fungus- growing termites and fungus-growing ants.

We have used Illumina metagenome sequencing to show that the gut microbiomes of fungus-growing termites have a huge potential of producing glycoside hydrolase enzymes to break-down oligosaccharides into sugars, complementing the initial breakdown of polysaccharides by the fungus garden symbiont Termitomyces. This study also provided the first evidence for gut microbiomes of reproductive (termite queens) being very different from those of workers and soldiers.

We have just completed 454 pyrosequencing studies on the gut microbiomes of representative Panamanian fungus-growing ants, showing that here the number of truly symbiotic bacteria is fairly low, but that these few bacterial species appear to have key roles in the preservation of nitrogen. We also showed for the first time how gut bacterial communities are affected by external microbiomes and the environment. This work has been extended to investigate the bacterial communities of Megalomyrmex social parasites and their Sericomyrmex, Trachymyrmex and Cyphomyrmex fungus-farming hosts, providing indications of possible horizontal transfers of symbiotic bacteria between unrelated ant species living on the same fungus food.

Questions asked

  • What is the composition of the gut bacteria across the fungus-growing ants and termites and how do these bacterial communities vary over time and between field and lab rearing conditions?
  • Which of these bacteria are intracellular and in what kind of host cells/tissues are they located? Locations and functions are likely to be very specific when bacteria true symbionts.
  • What is the function of well integrated bacterial symbionts and how does the expression of function depend on whether fungus-growing ants also rear bacterial cultures of Actinobacteria on their cuticle to produce antibiotics for biological control of fungus garden disease?

Research themes

Disease and Immunity; Fungus growing ants; Termite Fungiculture 

Research tools

Genetic analyses; GenomicsLaboratory colonies; Microscopy; Fieldwork