Microplastics alter the microbiota-mediated phosphorus profiles at sediment-water interface: Distinct microbial effects between sediment and plastisphere

Xiaojun Song; Hua Zou; Yunbo Zhang; Jiaxin Yang; Jiannan Ding

doi:10.1016/j.scitotenv.2024.173048

Microplastics alter the microbiota-mediated phosphorus profiles at sediment-water interface: Distinct microbial effects between sediment and plastisphere

Sci Total Environ. 2024 May 11:933:173048. doi: 10.1016/j.scitotenv.2024.173048. Online ahead of print.

Authors

Xiaojun Song¹, Hua Zou², Yunbo Zhang¹, Jiaxin Yang¹, Jiannan Ding³

Affiliations

¹ School of Environment & Ecology, Jiangnan University, Wuxi 214122, China.
² School of Environment & Ecology, Jiangnan University, Wuxi 214122, China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou 215009, China; Biomass Energy and Biological Carbon Reduction Engineering Center of Jiangsu Province, Wuxi 214122, China. Electronic address: zouhua@jiangnan.edu.cn.
³ School of Environment & Ecology, Jiangnan University, Wuxi 214122, China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou 215009, China; Biomass Energy and Biological Carbon Reduction Engineering Center of Jiangsu Province, Wuxi 214122, China. Electronic address: djn@jiangnan.edu.cn.

PMID: 38740204
DOI: 10.1016/j.scitotenv.2024.173048

Abstract

Microplastics (MPs) are ubiquitous in freshwater sediments, raising concern about their potential impacts on ecosystem services. However, the specific impacts of microbiota mediated by MPs in sediment and plastisphere compartments on P availability remain elusive. This investigation conducted a series of microcosm experiments utilizing eutrophic lake sediment amended with fuel-based polyethylene terephthalate (PET), bio-based polylactic acid (PLA) MPs, and a natural cobblestone substrate to unravel their effects. The findings highlighted that MPs induced alterations in bacterial communities in both sediment and plastisphere, consequently modifying P availabilities at the sediment-water interface (SWI). In comparison to non-biodegradable PET, biodegradable PLA MPs presented higher proportions of specific bacteria and functional genes associated with P profiles, such as Firmicutes, Ignavibacteriota, and P mineralizing genes in the sediment and plastisphere. This, in turn, elevated the levels of soluble reactive P in the porewater by 54.19 % (0-1 cm), 55.81 % (1-3 cm), and 18.24 % (3-5 cm), respectively. Additionally, PLA obviously altered P immobilization capacity and bioavailability, increasing the organic P fraction. Whereas, inert cobblestone exhibited negligible influence on P biogeochemical processes during the incubation. Moreover, the biofilm communities and those in the surrounding sediment specifically contributed to the changes in P profiles at the SWI. The functional genes associated with P profiles in the sediment mainly concentrate on P mineralization and P uptake/transport. In the plastisphere, P activation genes are obviously affected under MP exposure. This study fills the knowledge gap concerning the repercussions of MPs on ecosystem services.

Keywords: Cobble; Microcosm; PAOs; PET; PLA.