With a little help from my friends: "understanding the roles and importance of the millipede gut microbiome"

Julius Eyiuche NWEZE

Doctoral thesis

Abstract:

This research aimed to elucidate the role and importance of the millipede gut microbiome in cellulose digestion by using inhibitors to disrupt potential host-symbiosis and assessing their effects on millipede digestion and overall health. It involved the first comprehensive profiling of microbial communities within the hindgut and faeces of two distinct millipede species: Epibolus pulchripes, a tropical species found on the East African coast, and Glomeris connexa, a temperate species native to Central Europe. Although both species share a similar detritivorous lifestyle, they differ in size and gut redox conditions, with G. connexa being smaller (10-17 mm) than E. pulchripes (130-160 mm). The study also revealed the potential of the hindgut bacterial community in breaking down complex polysaccharides and recycling nutrients. It described the active bacterial community vital for certain processes and the extent of the millipedes' dependence on them. Additionally, the research provided a comprehensive investigation of viral communities in the hindguts of the two millipedes and their role in enhancing metabolism and modulating microbial composition. Furthermore, it introduced a new perspective that millipedes primarily ingest litter to gain access to microbial biomass (primarily fungal), which they and their gut microbiota consume.

Abstract:

This research aimed to elucidate the role and importance of the millipede gut microbiome in cellulose digestion by using inhibitors to disrupt potential host-symbiosis and assessing their effects on millipede digestion and overall health. It involved the first comprehensive profiling of microbial communities within the hindgut and faeces of two distinct millipede species: Epibolus pulchripes, a tropical species found on the East African coast, and Glomeris connexa, a temperate species native to Central Europe. Although both species share a similar detritivorous lifestyle, they differ in size and gut redox conditions, with G. connexa being smaller (10-17 mm) than E. pulchripes (130-160 mm). The study also revealed the potential of the hindgut bacterial community in breaking down complex polysaccharides and recycling nutrients. It described the active bacterial community vital for certain processes and the extent of the millipedes' dependence on them. Additionally, the research provided a comprehensive investigation of viral communities in the hindguts of the two millipedes and their role in enhancing metabolism and modulating microbial composition. Furthermore, it introduced a new perspective that millipedes primarily ingest litter to gain access to microbial biomass (primarily fungal), which they and their gut microbiota consume.

Keywords

Millipedes, Epibolus pulchripes, Glomeris connexa, hindgut, microbes, virsues, plant litter, methane, metagenomics, metatranscriptomics, RNA-SIP, CARD-FISH, polysacchride degradation, nitrogen cycling, sulphur cycling, acetogenesis, urolytic bacteria, protists

Language used: English

Date on which the thesis was submitted / produced: 30. 4. 2024

Thesis defence

• Supervisor: MSc. Roey Angel, Dr. rer. nat.

UNIVERSITY OF SOUTH BOHEMIA IN ČESKÉ BUDĚJOVICE

Faculty of Science

Doctoral programme / field:
Biology / Ecosystem Biology