Assessment of mutualism between Bombus terrestris and its microbiota by use of microcolonies

Abstract

International audienceSocial pollinators, like honeybees and bumblebees, have specific microbiota. The specific association between the insect and its gut microbiota could lead to a functional dependence. In this project, we investigated whether an alteration in microbiota could influence the fitness of the generalist pollinator Bombus terrestris. We used bumblebee workers in microcolonies to assess effects on colony development and reproduction. Treatment with 200 ppm streptomycin and tetracycline resulted in a disruption of gut microbiota, and typically there was 100 % worker mortality. In contrast, treatment with streptomycin alone showed an improved reproduction and this concurred with a different gut microbiota pattern. The results are discussed in relation to effects of the gut microbiota on bumblebee fitness and potential beneficial effects by Lactobacillus sp. These data may open new avenues in the mass-rearing of bumblebees used for the biological pollination in agriculture

A prokaryotic–eukaryotic relation in the fat body of Bombus terrestris

“…The dissected gut (mid‐ and hindgut) and fat body tissue were prepared for bacterial DNA extraction. To extract the bacterial DNA, each tissue was individually crushed in a 170 μl lysozyme solution (100 mg/ml) and DNA was extracted as described in Meeus and colleagues (). To identify bacterial symbionts occurring in both fat body and gut of bumblebees, the hypervariable V4 region (254 bp) of the 16S rRNA gene was amplified in triplicate, using 515F and 806R primers designed by Caporaso and colleagues ().…”

Plasticity in the gut microbial community and uptake of Enterobacteriaceae (Gammaproteobacteria) in Bombus terrestris bumblebees’ nests when reared indoors and moved to an outdoor environment

“…All equipment used was disinfected with 75 % ethanol between each individual dissection. The extraction of bacterial DNA was done as previously described (Meeus et al 2013), and then the V4 region of the ribosomal RNA (rRNA) was amplified in triplicate, using the 515F and 806R primers elongated with multiplex identifiers (Caporaso et al 2011). The composite primers include the 16S primer sites, a different nucleotide barcode (on the 806R primer) and the Illumina adapter sequences necessary for bridge amplification on the Illumina MiSeq flow cell (Illumina, San Diego, CA).…”

“…Some insects harbor gut communities of specific bacteria, which is especially true in social insects . Within the clade of social bees, research on microbial communities has been focusing on honeybees (Martinson et al 2012;Moran et al 2012) and bumblebees (Koch and Schmid-Hempel 2011b;Meeus et al 2013;Li et al 2015;Praet et al 2015) because of their important pollinating role in natural ecosystems and of many agricultural crops, together with a growing evidence of their dramatic declines worldwide (Ghazoul 2005;Lebuhn et al 2013).…”

Effect of oral administration of lactic acid bacteria on colony performance and gut microbiota in indoor-reared bumblebees (Bombus terrestris)

“…The bumblebees were obtained from an indoor massproduction facility (Biobest, Westerlo, Belgium). Microcolonies have been proven comparable to queen-right colonies for investigating microbiota (Meeus et al 2013), and microcolonies follow a welldefined development pattern with quantifiable parameters, such as time point of egg laying, larval development time, pupation time, and reproductive output. In each microcolony, one worker becomes dominant and starts laying unfertilized eggs that develop into drones, while the other workers take care of the brood.…”

“…The gut was subsequently crushed in a 170-μL lysozyme solution (100 mg/mL) and DNA extraction was performed as described in Meeus et al (2013). The hypervariable V4 region (254 bp) of the 16S rRNA was amplified in triplicate, using the 515F and 806R primers designed by Caporaso et al (2011).…”