The conserved nature of nitrogen recycling within the bacterial pouch of Tetraponera ants

These interactions supported by nutrient-provisioning symbionts have been a key driver that enables them to thrive in various nutrient imbalanced niches, thereby contributing to their widespread ecological dominance. Herbivorous ants, in particular, face the challenge of acquiring sufficient nitrogen, often relying on symbiotic bacteria for nitrogen provisioning. Several herbivorous ant groups engage in symbioses with either intracellular symbionts or large masses of gut bacteria to supplement deficient nitrogen in their diet. Ants in Tetraponera nigra-group are functionally herviborous, primarily subsisting on honeydew produced by Hemipteran insects. A pouch-like structure between midgut and hindgut with connection to multiple tracheae and Malpighian tubules has been found to harbor a large number of bacteria in this group of Tetraponera ants. Given their persistence on nitrogen-limited diets, this specialized symbiotic organ exhibits features that facilitate bacterial contributions on nitrogen provisioning for ant hosts. While the symbiotic bacteria in bacterial pouch have been identified as belonging to Rhizobiales via traditional Sanger sequencing-based approach, the comprehensive picture of the bacterial community structure within this specialized symbiotic organ remain poorly understood. Therefore, we performed 16S rRNA amplicon sequencing on the abdomens of ant individuals from the Tetraponera nigra group to characterize the composition and structure of bacterial communities in the bacterial pouch.