Differences in honey bee bacterial diversity andcomposition in agricultural and pristine environments–afield study

Agrochemicals and biocides are suspected to cause a dysbiosis of honey bee microbiota, decreasing colonies ability to respond to the environment. As a first step to investigate agriculture and beekeeping impact, hives bacteriomes from an anthropized environment (Agri-env) were compared to that of pristine's (Prist-env). 16S rRNA sequencing evidenced differences in richness and composition between sample types (Gut (G), Brood (B), Bee-bread (BB)) and environments. Higher opportunist loads and shifts toward taxa capable of metabolizing insecticides were observed in G and B at Agri-env, while beneficial bacteria were enriched in Prist-env. Bacteria in BB did not differ, the acidity of the niche outweighing the influence of external factors. Results showed the environment plays a major role in shaping honey bee microbiota, the agricultural realm inducing a bacterial disruption that would let to colonies vulnerability. In contrast, a less susceptible bee will be promoted in less anthropized locations.The authors thank for technical and human support provided by General Genomics Service -Sequencing and Genotyping Unit -SGIker of UPV/EHU and European funding (ERDF and ESF). We are grateful to Dr. Mikel Aguirre for his support with bioinformatics. We are also grateful to the "Sustainable Management of Resilient Bee Populations (SMARTBEES) project (7PM-COOP-LCP13/08) for their collaboration. This research was supported by the Genomic Resources research group (http://www.genomic-resources.eus) of the Basque University System (IT1014-16) supported by the Department of Education, Universities and Research of the Basque government. Editoria