Best Buds: Investigating the Tripartite Relationship Between Microbes, Floral Nectar, and Bees

Access Restricted

Access to this document is restricted. Some items have been embargoed at the request of the author, but will be made publicly available after the "No Access Until" date.

During the embargo period, you may request access to the item by clicking the link to the restricted file(s) and completing the request form. If we have contact information for a Cornell author, we will contact the author and request permission to provide access. If we do not have contact information for a Cornell author, or the author denies or does not respond to our inquiry, we will not be able to provide access. For more information, review our policies for restricted content.

No Access Until

Permanent Link(s)

Other Titles


Floral and pollinator microbiomes profoundly impact both ecosystem health and agricultural productivity. However, there are limited integrated studies investigating the shared microbial taxa within these environments, how they shift over time, and how microbes adapt to these habitats. This study aims to bridge this knowledge gap by examining the ecology and evolution of bacterial species that inhabit floral-pollinator environments, and highlighting taxa of interest. We explore the temporal patterns of microbial communities within flowers and pollinators across different ecologically managed environments. 16s rRNA amplicon sequencing of floral, bee crop, and pollen provision samples collected over a growing season from four distinct field sites revealed 279 shared microbial genera, including Acinetobacter, Lactobacillus, Pseudomonas, Bacillus, and Sphingomonas. Temporal analyses unveiled variations in microbial abundance throughout the growing season and distinct temporal patterns between agriculturally managed and unmanaged land. Despite differences across sites, seasons, and land management types, environmental exposure through foraging and land management practices was found to be critical in shaping microbial community structures. The study underscores the integral role of pollinator visitation in shaping floral microbiomes and highlights the importance of understanding these microbial dynamics for the conservation of bee populations and microbial dispersal within agricultural ecosystems. Acinetobacter, a floral nectar specialist, was of particular interest due to its adaptation from soil to floral nectar environments. Phylogenomic analysis of 15 novel Acinetobacter isolates and related strains reveals that nectar-associated Acinetobacter species form a distinct clade, suggesting specialization to these habitats. This ecological shift has driven significant genomic changes, including a reduction in gene number and the acquisition of genes beneficial to colonizing nutrient poor floral nectar environments. Ancestral reconstruction analyses reveal the significant gene losses and gains that optimize nutrient access in nectar, offering insights into the bacterial diversification triggered by extreme changes in selective pressures. These findings represent a significant step towards a more comprehensive understanding of the complexity of microbial communities within pollinator-floral environments.

Journal / Series

Volume & Issue


102 pages

Supplemental file(s) description: Supplementary Table 4: Ortholog hits to Amino Acid RAST annotation subcategory in the Acinetobacter genomes.


Date Issued




Acinetobacter; Bees; Floral microbiome; Polygalacturonase


Effective Date

Expiration Date




Union Local


Number of Workers

Committee Chair

Hendry, Tory

Committee Co-Chair

Committee Member

Peters, Joseph
Moreau, Corrie
McArt, Scott

Degree Discipline


Degree Name

Ph. D., Microbiology

Degree Level

Doctor of Philosophy

Related Version

Related DOI

Related To

Related Part

Based on Related Item

Has Other Format(s)

Part of Related Item

Related To

Related Publication(s)

Link(s) to Related Publication(s)


Link(s) to Reference(s)

Previously Published As

Government Document




Other Identifiers


Rights URI


dissertation or thesis

Accessibility Feature

Accessibility Hazard

Accessibility Summary

Link(s) to Catalog Record