Specialisation of Yeast Genera in Different Phases of Bee Bread Maturation.

Etienne Bruneau,Noa Simon-Delso,Heide-Marie Daniel,Roxane Detry

doi:10.3390/microorganisms8111789

Etienne Bruneau, Noa Simon-Delso + Show 2 more

Open Access

https://doi.org/10.3390/microorganisms8111789

Copy DOI

Journal: Microorganisms	Publication Date: Nov 14, 2020
Citations: 32	License type: CC BY 4.0

Affiliation: Université Catholique de Louvain

Abstract

Pollen stored by bees undergoes a fermentation marked by the presence of lactic acid bacteria and yeasts. It results in bee bread. Past studies have singled out Starmerella (Candida) magnoliae as the most common yeast species in honey bee-stored bee bread. Starmerella species are ecological specialists with potential biotechnological value. The rarity of recent studies on yeasts in honey bees prompted us to generate new information on yeast diversity during the conversion of bee-collected pollen to bee bread. Bees and stored pollen from two apiaries in Belgium were sampled, a yeast isolation protocol was developed, yeast isolates were grouped according to their macro- and micromorphology, and representative isolates were identified using DNA sequences. Most of the 252 identified isolates belonged to the genera Starmerella, Metschnikowia, and Zygosaccharomyces. The high abundance of yeasts in fresh bee bread decreased rapidly with the storage duration. Starmerella species dominated fresh bee bread, while mostly Zygosaccharomyces members were isolated from aged bee bread. Starmerella (Candida) apis, a rarely isolated species, was the most frequent and abundant species in fresh bee bread. Yeasts from the bee’s honey stomach and from pollen pellets obtained from bees hind legs were dominated by Metschnikowia species. The distinctive communities from pollen pellets over fresh bee bread to aged bee bread indicate a non-random distribution of these yeasts.

Highlights

Honey bees (Apis mellifera) collect and store nectar, and pollen
Could the preference of bees to consume freshly stored pollen over aged bee bread [14] be linked to yeast activity? Pollen substitutes benefit from the addition of dried brewer’s yeast, a practice still in use [2], and the advantage over yeast-free substitutes has been linked to the contribution of vitamins by the yeast [39]
Stored honey bee pollen in Belgium was dominated by Starmerella species, in particular S. apis

Summary

Introduction

Honey bees (Apis mellifera) collect and store nectar, and pollen. Nectar and honey serve as their main carbohydrate source, while pollen serves as a source of proteins, lipids, vitamins and minerals [1]. Most of the pollen is consumed by nurse bees who rely on it for the production and secretion of amino acid-rich royal jelly. The jelly, and later a jelly/pollen mix, is fed to the worker and drone larvae until they seal themselves in their cocoons. The queen larvae receive a steady diet of royal jelly throughout their development. Appropriate nutrition induces the development of the flight muscles, the hypopharyngal glands and the ovaries [2]

Methods

Results

Discussion

Conclusion