Microbial Community Structure among Honey Samples of Different Pollen Origin

Abstract

Honey’s antibacterial activity has been recently linked to the inhibitory effects of honey microbiota against a range of foodborne and human pathogens. In the current study, the microbial community structure of honey samples exerting pronounced antimicrobial activity was examined. The honey samples were obtained from different geographical locations in Greece and had diverse pollen origin (fir, cotton, fir–oak, and Arbutus unedo honeys). Identification of honey microbiota was performed by high-throughput amplicon sequencing analysis, detecting 335 distinct taxa in the analyzed samples. Regarding ecological indices, the fir and cotton honeys possessed greater diversity than the fir–oak and Arbutus unedo ones. Lactobacillus kunkeei (basionym of Apilactobacillus kun-keei) was the predominant taxon in the fir honey examined. Lactobacillus spp. appeared to be favored in honey from fir-originated pollen and nectar since lactobacilli were more pronounced in fir compared to fir–oak honey. Pseudomonas, Streptococcus, Lysobacter and Meiothermus were the predominant taxa in cotton honey, whereas Lonsdalea, the causing agent of acute oak decline, and Zymobacter, an osmotolerant facultative anaerobic fermenter, were the dominant taxa in fir–oak honey. Moreover, methylotrophic bacteria represented 1.3–3% of the total relative abundance, independently of the geographical and pollen origin, indicating that methylotrophy plays an important role in honeybee ecology and functionality. A total of 14 taxa were identified in all examined honey samples, including bacilli/anoxybacilli, paracocci, lysobacters, pseudomonads, and sphingomonads. It is concluded that microbial constituents of the honey samples examined were native gut microbiota of melliferous bees and microbiota of their flowering plants, including both beneficial bacteria, such as potential probiotic strains, and animal and plant pathogens, e.g., Staphylococcus spp. and Lonsdalea spp. Further experimentation will elucidate aspects of potential application of microbial bioindicators in identifying the authenticity of honey and honeybee-derived products.

The buzz about honey-based biosurveys

“…The ability to investigate the bee gut microbiota from honey samples may serve as an additional tool for monitoring the health of bee colonies 8,9,77 . The gut microbiota of adult honey bees are observed to be low complexity communities, with the composition of the microbial communities influenced by diet 78 as well as through social interactions with other members of the hive 79,80 .…”

“…Aside from bee-related taxa, honey was also found to contain genetic information from animal-and plant-associated microorganisms containing both beneficial and pathogenic species 77 . This presents a critical avenue to explore and monitor the environmental microbiome for deleterious changes that could threaten biodiversity within an ecosystem of interest 87 .…”

Microbial Diversity in Bee Species and Bee Products: Pseudomonads Contribution to Bee Well-Being and the Biological Activity Exerted by Honey Bee Products: A Narrative Review

“…The European Union (EU) is the second biggest (after China) honey producer worldwide. Spain, Romania, Greece, Poland, France, and Italy are the major honey-producing EU countries [54]. Both honey bees and stingless bees produce honey as the main carbohydrate nutritional source [5,55].…”

“…They suggested that low oxygen levels in honey might affect the structure of the microbial community. Overall, the investigated honey microbiota comprised bacteria present in the bee gut, both beneficial bacteria (probiotics) as well as pathogenic microbes of botanical origin [54].…”

Green Antimicrobials

“…In fact, they detected 335 distinct taxa in honey microbiota, native to the gut microbiota of melliferous bees and microbiota of their flowering plants, including beneficial bacteria like probiotic strains. These could work as indicators of the authenticity of honey, facilitating the identification of honey samples with potent antimicrobial profiles [8]. β-Glucan is an important natural prebiotic abundant in lentinan, cereals and the yeast cell wall.…”