Effects of long-term fertilization on the associated microbiota of soil collembolan

Abstract

Soil fauna plays crucial roles in litter decomposition and nutrient cycling and their associated microbiota contributes to nutrient absorption, health, metabolism and immunity. However, only a few studies have focused on the associated microbiota of soil fauna, and the effects of fertilization on the bacterial community assembly of soil fauna are poorly understood. Here we collected specimens of the collembolan Folsomia quadrioculata and the soils they lived in from a long-term fertilization experiment (including urea, sewage sludge and chicken manure). The bacterial communities of the collembolans and soils were investigated using 16S rRNA gene amplicon sequencing. A dominant core microbiota consisting of 244 OTUs were identified in the collembolans, of which 41% were shared with the soil microbiota. Community analysis indicated that the assembly of the collembolan bacterial community was a deterministic process, and a close contact of bacterial community was observed in the collembolan microbiome. The collembolan bacterial communities differed significantly from their surrounding soil samples, and their diversity was lower than that of soil microbial community. Furthermore, soil fertilization and in particular application of inorganic fertilizer altered the bacterial community and metabolic potential of the collembolan associated microbiota. Changes in the soil microbial community moreover played an important role in the shift in bacterial community and metabolic potential of the collembolan-associated microbiota. Our results suggested that long-term fertilization significantly contributed to the assembly of the collembolan bacterial community.