Carnivory does not change the rhizosphere bacterial community of the plant Drosera intermedia

• We studied bacterial communities of bulk soil and rhizosphere from the carnivorous plant Drosera intermedia.
• Composition of rhizosphere bacterial communities did not change with plant nutrient source (soil or preys).
• Rhizosphere bacterial communities strongly differed from those of bulk soil (taxonomically and phylogenetically).

Carnivorous plants are also green plants, and some are even able to grow and reproduce in the absence of prey, which implies that they should be able to capture nutrients from their roots. We studied the rhizosphere bacterial community of the carnivorous plant Drosera intermedia and examined whether it is influenced by the plant nutrient source, i.e., soil or preys. Notably, we did not observe any differences in the bacterial communities of plants after ten weeks feeding on prey or soil. Further, rhizosphere nutrient pools (mineral N and P and organic N and C) were not affected by plant feeding regime. We found that D. intermedia has a well-defined rhizosphere bacterial community, mainly composed by OTUs from phyla Proteobacteria (40%), Acidobacteria (27%), Actinobacteria (9%) and Firmicutes (5%). This community is richer (alpha diversity) than the bulk soil bacterial community at the taxonomic, although there was no differences in phylogenetic diversity. We also found that these communities differed when considering qualitative (presence–absence of OTUs) and quantitative (abundance of OTUs) measurements at taxonomic and phylogenetic levels. These results, together with the lack of effect due to feeding regime, suggest that rhizosphere bacterial community of D. intermedia is metabolically diverse to cope with changes in plant physiology condition.