Microbiota associated with pollen, bee bread, larvae and adults of solitary beeOsmia cornuta(Hymenoptera: Megachilidae)

Abstract

Using cultivation-dependant method, we isolated 184 strains from fresh and old bee bread, pollen, larvae and adults of solitary bee Osmia cornuta. The 16S rDNA sequencing of 79 selected isolates gave the final species-specific identification of strains. Phylogenetic analysis indicated that microbiota isolated from five different sources were represented with 29 species within three different phyla, Firmicutes with 25 species, Actinobacteria with only one species and Proteobacteria with three species of Enterobacteriaceae. Bacterial biodiversity presented with Shannon-Wiener index (H') was highest in the alimentary tract of adults and old bee bread (H' = 2.43 and H' = 2.53, respectively) and in the same time no dominance of any species was scored. On the contrary, results obtained for Simpson index (D) showed that in pollen samples the dominant species was Pantoea agglomerans (D = 0.42) while in fresh bee bread that was Staphylococcus sp. (D = 0.27). We assume that microbial diversity detected in the tested samples of solitary bee O. cornuta probably come from environment.

Linking pollen foraging of megachilid bees to their nest bacterial microbiota

“…On the other hand, solitary bee nests harbor highly diverse bacterial communities (Keller, Grimmer, & Steffan‐Dewenter, ; Lozo et al, ; McFrederick & Rehan, ; Mohr & Tebbe, ; Voulgari‐Kokota, Grimmer, Steffan‐Dewenter, & Keller, ). However, only few studies have dealt with their role in larval health (Keller et al, ; McFrederick, Vuong, & Rothman, ) or their acquisition routes (McFrederick et al, ; Voulgari‐Kokota, McFrederick, Steffan‐Dewenter, & Keller, ).…”

“…Considering that the multiple aspects of solitary bee ecology can form distinctive nesting conditions for different species, we test the hypothesis that different pollen foraging patterns could establish different routes for bacterial colonization in the nest. Previous studies have undertaken the task of characterizing solitary bee nest microbiota (Keller et al, ; Lozo et al, ; McFrederick et al, ; Voulgari‐Kokota, Grimmer, et al, ) or have identified the plant composition of pollen provisions (Danner, Keller, Härtel, & Steffan‐ Dewenter, ; Sickel et al, ; Villanueva‐Gutiérrez & Roubik, ). Simultaneous examination of pollen composition and pollen microbiota from the nests of a wild bee species has shown covariation across different landscapes, even though the causality of this association was not clear (McFrederick & Rehan, ).…”

“…VOULGARI-KOKOTA eT AL. Lozo et al, 2015;McFrederick & Rehan, 2016;Mohr & Tebbe, 2006;Voulgari-Kokota, Grimmer, Steffan-Dewenter, & Keller, 2019).…”

Floral and Foliar Source Affect the Bee Nest Microbial Community

“…For example, McFrederick et al [9] found that flower and wild megachilid bee samples can share the same taxon of Lactobacillus, and that this bacterium can dominate the microbial community of all life stages of the bee and its pollen provision. Likewise, in 2015, Lozo et al [14] found that pollen collected by the mason bee Osmia cornuta contains mostly the environmentally acquired cosmopolitan bacterium Pantoea agglomerans. Recently, it has been established that providing honey bees with different sources of floral forage can subtly alter the gut microbiome [15,16], and that bees may alter the composition of floral microbial diversity [17,18].…”

<i>Pantoea agglomerans</i>: a mysterious bacterium of evil and good. Part III. Deleterious effects: infections of humans, animals and plants

“…Pantoea agglomerans strains occur commonly -usually as symbionts -in arthropods, mostly insects [68]. Among others, they were found to be associated with social insects, such as bees [69,70], ants [71], and termites [72]. N 2 -fixing P. agglomerans strains found in the guts of wood-eating termites were identified as a potential source of nitrogen for these insects [72].…”