Analysis of bacteria associated with honeys of different geographical and botanical origin using two different identification approaches: MALDI-TOF MS and 16S rDNA PCR technique.

Paweł Pomastowski,Markus Kostrzewa,Magda Ligor,Michał Złoch,Bogusław Buszewski,Agnieszka Rodzik,Doralyn S Dalisay

doi:10.1371/journal.pone.0217078

Paweł Pomastowski, Markus Kostrzewa + Show 5 more

Open Access

https://doi.org/10.1371/journal.pone.0217078

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Abstract

In the presented work identification of microorganisms isolated from various types of honeys was performed. Martix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rDNA sequencing were applied to study environmental bacteria strains.With both approches, problematic spore-forming Bacillus spp, but also Staphylococcus spp., Lysinibacillus spp., Micrococcus spp. and Brevibacillus spp were identified. However, application of spectrometric technique allows for an unambiguous distinction between species/species groups e.g.B. subtilis or B. cereus groups. MALDI TOF MS and 16S rDNA sequencing allow for construction of phyloproteomic and phylogenetic trees of identified bacterial species. Furthermore, the correlation beetween physicochemical properties, geographical and botanical origin and the presence bacterial species in honey samples were investigated.

Highlights

Honey, a supersaturated solution of sugars produced by Apis mellifera, is the first and most reliable sweetener used by human beings [1]
Our studies revealed that regardless geographical and botanical origin, honeys are by far dominated by spore-forming Bacillus spp
According to literature and our own observations, the most frequently isolated honey bacteria belong to the B. subtilis or B. cereus group, which raises big problems with identification to the species level via 16S rDNA technique

Summary

Introduction

A supersaturated solution of sugars (mostly glucose and fructose) produced by Apis mellifera, is the first and most reliable sweetener used by human beings [1]. High antibacterial effect of honey is primarily related to the high sugar concentration. This implicates its hyperosmotic nature, high viscosity, and low water content which in consequence prevent the growth or even survival of most vegetative forms of human pathogenic microorganisms by their desiccation as well as limited atmospheric oxygen penetration [4],[5]. Natural acidity of this product, the ability to produced hydrogen peroxide, and presence of numerous phytochemical factors such as phenols, terpenes or flavonoids (e.g. pinacombrin) cause that honey has a permanent place in the treatment of wound infections and burns [6],[7],[8].

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