Addressing the diversity of the honeybee gut symbiont Gilliamella: description of Gilliamella apis sp. nov., isolated from the gut of honeybees (Apis mellifera)

Abstract

The gut microbiota of honeybees (Apis) and bumblebees (Bombus) include the symbiotic bacterial genus Gilliamella. This genus shows a high degree of functional and genomic diversity and separates into distinct lineages. Gilliamella apicola wkB1, which was isolated from Apis, was the first species to be described. Recently four new species, isolated from Bombus, were identified. In this paper, we compare several genomes/strains from previous studies spanning this diversity, which gives insight into the phylogenetic relationship among different Gilliamella species. We show that one lineage, isolated only from Apis, is different from other gilliamellas described, based on average nucleotide identity calculation (about 80 %) and phenotypic characterizations. We propose the new species name for this lineage: Gilliamella apis sp. nov. We present the characterization of the type strain NO3 (=DSM 105629=LMG 30293), a strain isolated from the Western honeybee Apis mellifera, which clusters within this lineage. Cells of strain NO3 grow best in a microaerophilic atmosphere with enhanced CO2 levels at 36 °C and pH 7.0-7.5. Cells also grow well in anaerobic conditions, but not in aerobic conditions. Cells are approximately 1 µm in length and rod-shaped, and the genomic G+C content is 34.7 mol%. Differential characteristics between strain NO3 and the different type strains of Gilliamella were revealed based on API kit tests and genomic content comparisons. The main respiratory quinone of strain NO3 was ubiquinone-8, and the predominant fatty acids were C18 : 1ω7c/C18 : 1ω6c, C16 : 0, consistent with the genus Gilliamella.

Bacterial Communities in Three Parts of Intestinal Tracts of Carpenter Bees (Xylocopa tenuiscapa)

“…Although Gillamella are not classified as LAB, they provide similar functions. Studies have reported that Gillamella apicola were fermentative bacteria in the honey bee’s gut and supported hosts in the utilization, fermentation and uptake of some essential sugars that were indigestible by bees [ 45 , 46 , 47 ]. Similar to Lactobacillus and Bifidobacterium , Gillamella have been shown to protect hosts from pathogens.…”

The Effect of Pesticides on the Microbiome of Animals

“…As known, intestinal symbionts of insects inhibit the action of pathogens. The main symbiont bacteria, Snodgrassella alvi [86] and Gilliamella [87], were studied in the body of Apis mellifera and Bombus sp. It turned out that bees contain a greater number of bacterial strains than bumblebees, which confirms the hypothesis that the foundation of colonies by swarms of workers allows to keep a greater diversity than the foundation of colonies by one queen.…”

Genomic diversity landscape of the honey bee gut microbiota

“…From a taxonomic perspective, the extensive intra-phylotype diversity has resulted in some phylotypes now harboring multiple named species, and others harboring highly divergent lineages with the same species name 22 . Naming of species within phylotypes has so far mostly been motivated by divergence in the non-ribosomal part of the genomes and the aforementioned differences in metabolic profiles 23 , but also on ANI 24 . However, the natural population structure within phylotypes has not been systematically investigated, and it is unclear to what extent the named species represent discrete evolutionary lineages (SDPs).…”