PLEASE NOTE: Application deadline date 08 Jan 2024. Applications are no longer being accepted for this project
Project Overview
Microplastics in oceans are detrimental to marine biota and may also impact Earth’s biogeochemical cycles. However, their effects on microorganisms and microbial communities are poorly studied. This project will focus on the effect of on the microbial production and consumption of methane, an important greenhouse gas, in sediments.
Project Description
Millions of tonnes of plastic enter the oceans annually with effects on Earth system processes likely to exceed a ‘safe operating space’ for humanity (1). A myriad of consequences of microplastics on marine fauna have been described and plastics become colonized by microorganisms in what is termed the plastisphere. Overall, the impact of microplastics on microbial functions in marine systems is poorly characterized.
Methane is about 80-times as potent as carbon dioxide at trapping heat in the atmosphere and its production and consumption by microbes in marine systems is an important component of the global carbon cycle. Plastics can release methane during their degradation in the environment (2), which may contribute to fluxes to the atmosphere. This methane from plastics may directly stimulate the growth of microbes in the plastisphere that use methane as a carbon source. In addition, other chemicals released during the decomposition of plastics can modify the activity of microbes (3), potentially including those involved in methane cycling. Therefore, plastic waste in the ocean may have an important contribution to the methane cycle.
The objective of this work will be to investigate the effects of common microplastics on total methane production and specifically on the activity and community structure of methanogens and methane-oxidizing microbes (i.e., methanotrophs and ANME) using both cultivation and molecular biology approaches. Samples will include sediments from coastal sites and salt marshes, which are key sites of microplastic accumulation and methane cycling. This is a joint project with the Marine Biological Association (https://www.mba.ac.uk/).
The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at the School of Biological Sciences. Specific training will include:
- Methane gas flux analyses using gas chromatography
- Enrichment and isolation of environmental microorganisms
- Molecular biology methods including quantitative PCR
- High-throughput sequencing including both amplicon-based, genomics, and metagenomics
- Characterisation of biochemical pathways in methanotrophs, ANME, and methanogens
- Bioinformatics
1. Persson L., Carney Almroth B.M., Collins C.D. et al. (2022). Outside the safe operating space of the planetary boundary for novel entities. Environ Sci Technol 56: 1510–1521.
2. Royer S.-J., Ferrón S., Wilson S.T., Karl D.M. (2018). Production of methane and ethylene from plastic in the environment. PLoS ONE 13: e0200574.
3. Seeley M.E., Song B., Passie R. et al. (2020). Microplastics affect sedimentary microbial communities and nitrogen cycling. Nat Commun 11: 2372.
