Microplastic ingestion affects hydrogen production and microbiomes in the gut of the terrestrial isopod Porcellio scaber

authored by

Linda Hink, Anja Holzinger, Tobias Sandfeld, Alfons R Weig, Andreas Schramm, Heike Feldhaar, Marcus A. Horn

Abstract

Microplastic (MP) is an environmental burden and enters food webs via ingestion by macrofauna, including isopods (Porcellio scaber) in terrestrial ecosystems. Isopods represent ubiquitously abundant, ecologically important detritivores. However, MP-polymer specific effects on the host and its gut microbiota are unknown. We tested the hypothesis that biodegradable (polylactic acid [PLA]) and non-biodegradable (polyethylene terephthalate [PET]; polystyrene [PS]) MPs have contrasting effects on P. scaber mediated by changes of the gut microbiota. The isopod fitness after an 8-week MP-exposure was generally unaffected, although the isopods showed avoidance behaviour to PS-food. MP-polymer specific effects on gut microbes were detected, including a stimulation of microbial activity by PLA compared with MP-free controls. PLA stimulated hydrogen emission from isopod guts, while PET and PS were inhibitory. We roughly estimated 10

7 kg year

-1 hydrogen emitted from the isopods globally and identified their guts as anoxic, significant mobile sources of reductant for soil microbes despite the absence of classical obligate anaerobes, likely due to Enterobacteriaceae-related fermentation activities that were stimulated by lactate generated during PLA-degradation. The findings suggest negative effects of PET and PS on gut fermentation, modulation of important isopod hydrogen emissions by MP pollution and the potential of MP to affect terrestrial food webs.

Organisation(s)

Institute of Microbiology

External Organisation(s)

University of Bayreuth
Aarhus University

Type

Article

Journal

Environmental microbiology

Volume

Pages

2776-2791

No. of pages

ISSN

1462-2912

Publication date

19.12.2023

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Ecology, Evolution, Behavior and Systematics, Microbiology

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy, SDG 15 - Life on Land

Electronic version(s)

https://doi.org/10.1111/1462-2920.16386 (Access: Open)