Deciphering the Distinct Successional Patterns and Ecological Roles of Abundant and Rare Microbial Taxa of Urban Riverine Plastisphere

Abstract

Microbial colonization on microplastics has provoked global concern, yet the distribution profiles and ecological roles of abundant and rare taxa of plastisphere remain largely unknown. Here we investigate the colonization dynamics of abundant and rare taxa of riverine plastisphere by conducting microcosmic systems. Results showed that rare taxa occupied a broader niche breadth than abundant taxa and were indispensable components in maintaining the community diversity of plastisphere communities during colonization. Both stochastic and deterministic processes signally affected plastisphere community assemblies, and deterministic patterns (heterogeneous selection) were especially pronounced for rare biospheres. Plastisphere microbial networks were shaped by enhancing the network modularity and reinforcing positive interactions. Rare taxa played critical roles in shaping stable plastisphere by occupying key status in microbial networks. Rare and non-rare taxa interacted strongly, suggesting that multi-species collaboration might be conducive to the formation and stability of plastispheres. Both abundant and rare taxa were enriched with plentiful functional genes related to C, N, P and S cycling, but their potential metabolic functions were significantly discrepant, implying that abundant and rare microbes of plastisphere may play different roles in the ecosystem. Overall, this study strengthens our comprehending of the mechanisms regarding the formation and maintenance of the plastisphere.

Keywords: Plastisphere microbiome, Rare taxa, Ecological mechanism, Interaction pattern, Functional trait