Micro-organisms inhabiting animal guts benefit from a protected and nutrient-rich environment
while assisting the host with digestion and nutrition. In this study we compare, for the
first time, the bacterial and fungal gut communities of two species of the small desert dung
beetle genus Pachysoma feeding on different diets: the detritivorous P. endroedyi and the
dry-dung-feeding P. striatum. Whole-gut microbial communities from 5 individuals of each
species were assessed using 454 pyrosequencing of the bacterial 16S rRNA gene and fungal
ITS gene regions. The two bacterial communities were significantly different, with only
3.7% of operational taxonomic units shared, and displayed intra-specific variation. The
number of bacterial phyla present within the guts of P. endroedyi and P. striatum individuals
ranged from 6–11 and 4–7, respectively. Fungal phylotypes could only be detected within
the gut of P. striatum. Although the role of host phylogeny in Pachysoma microbiome
assembly remains unknown, evidence presented in this study suggests that host diet may
be a deterministic factor.
S1 Fig. Rarefactions curves showing gut microbial community richness of all Pachysoma individuals
for bacterial 16S rRNA gene amplicon data of: a) P. endroedyi, b) P. striatum; and c)
fungal ITS gene region amplicon data of P. striatum.
S2 Fig. Photographs of P. endroedyi (a) and P. striatum (b) in their natural environment
before collection (courtesy of Hennie de Klerk).