Cryptic microbial hydrocarbon cycling in the ocean


Cryptic microbial hydrocarbon cycling in the ocean


Project Description


Prof Terry J McGenity (University of Essex, School of Life Sciences) – Contact me

Dr Boyd A McKew (University of Essex, School of Life Sciences)

Dr David Lea Smith (University of East Anglia, School of Biological Sciences)

Dr Nikolai Pedentchouk (University of East Anglia, School of Environmental Sciences)


Project background

This PhD explores a hidden hydrocarbon cycle between phototrophic and heterotrophic microbes, which has extensive implications ranging from global carbon cycling to oil-spill response.

Marine cyanobacteria synthesise alkanes/alkenes, releasing 100 times more hydrocarbons into the ocean than oil seeps and pollution events! However, the sea is not awash with oil thanks to various microbes that degrade this steady, widespread, but low-concentration supply of hydrocarbons: the short-term hydrocarbon cycle1,2,3.

Microalgae (photosynthetic protists, such as diatoms) have much higher global biomass and diversity than cyanobacteria, producing a broader range of hydrocarbons4, yet their contribution to hydrocarbon cycling is unknown.


1) a more diverse microbial consortium is required to degrade the broad range of microalgal, rather than cyanobacterial, hydrocarbons, because most hydrocarbon-degrading species use a narrow range of hydrocarbons5,

2) both previously characterised and novel, uncultivated microbes will degrade hydrocarbons at natural low concentrations.


You will learn and employ a wide range of methods to test these hypotheses, and to explore others that arise. You will review the literature on microalgal hydrocarbons, and any under-represented taxa will be grown and their hydrocarbons profiled. Using marine samples from coastal cruises, you will identify how the phytoplankton community affects the composition of biogenic hydrocarbons.

These data will direct the design of laboratory experiments to identify which marine microbes degrade abundant microalgal alkanes/alkenes, e.g. using high-throughput sequencing and stable-isotope probing. There is plenty of scope to follow interesting leads, such as cultivating and characterising novel hydrocarbon-degrading microbes.


You will join the vibrant Ecology and Environmental Microbiology Research Group at the University of Essex, and also work with co-supervisors at the University of East Anglia. The experienced multi-disciplinary supervisory team will train you in skills that underpin the fields of environmental microbiology, biogeochemistry etc., such as gas-chromatography mass-spectrometry and high-throughput sequencing, and support your career progression, e.g. by helping you develop writing/analytical skills. There will also be opportunities to attend advanced courses (via ARIES, the University of Essex or externally) to develop techniques.

Person specification

We are looking for someone who is enthusiastic about understanding and protecting the environment.


  • Lea-Smith DJ, Biller SJ, Davey MP, Cotton CAR, Perez Sepulveda BM, Turchyn AV, Scanlan DJ, Smith AG, Chisholm SW, Howe CJ (2015) Major contribution of cyanobacterial alkane production to the ocean hydrocarbon cycle. Proc Natl Acad Sci USA 112:13591-13596
  • Love CR, Arrington EC, Gosselin KM, Reddy CM, Van Mooy BAS, Nelson RK, Valentine DL (2021) Microbial production and consumption of hydrocarbons in the global ocean. Nature Microbiol 6:489–498 3 McGenity TJ, McKew BA, Lea-Smith DJ (2021) Cryptic microbial hydrocarbon cycling. Nature Microbiol 6:419-420.
  • McGenity TJ, McKew BA, Lea-Smith DJ (2021) Cryptic microbial hydrocarbon cycling. Nature Microbiol 6:419-420.
  • McKew BA, Coulon F, Osborn AM, Timmis KN, McGenity TJ (2007) Determining the identity and roles of oil-metabolizing marine bacteria from the Thames estuary, UK. Environ Microbiol 9:165-176.
  • Tréguer P, Bowler C, Moriceau B, Dutkiewicz S, Gehlen M, Aumont O et al. (2018) Influence of diatom diversity on the ocean biological carbon pump. Nature Geosci 11:27–37.

Key Information

  • This project has been shortlisted for funding by the ARIES NERC DTP and will start on 1st October 2023. The closing date for applications is 23:59 on 11th January 2023.
  • Successful candidates who meet UKRI’s eligibility criteria will be awarded a NERC studentship, which covers fees, stipend (£17,668 p.a. for 2022/23) and research funding. International applicants are eligible for fully-funded ARIES studentships including fees. Please note however that ARIES funding does not cover additional costs associated with relocation to, and living in, the UK.
  • ARIES students benefit from bespoke graduate training and ARIES provides £2,500 to every student for access to external training, travel and conferences, on top of all Research Costs associated with the project. Excellent applicants from quantitative disciplines with limited experience in environmental sciences may be considered for an additional 3-month stipend to take advanced-level courses.
  • ARIES is committed to equality, diversity, widening participation and inclusion in all areas of its operation. We encourage enquiries and applications from all sections of the community regardless of gender, ethnicity, disability, age, sexual orientation and transgender status. Academic qualifications are considered alongside non-academic experience, and our recruitment process considers potential with the same weighting as past experience.
  • All ARIES studentships may be undertaken on a part-time or full-time basis, visa requirements notwithstanding
  • For further information, please contact the supervisor. To apply for this Studentship follow the instructions at the bottom of the page or click the 'apply now' link.
  • ARIES is required by our funders to collect Equality and Diversity Information from all of our applicants. The information you provide will be used solely for monitoring and statistical purposes; it will remain confidential, and will be stored on the UEA sharepoint server. Data will not be shared with those involved in making decisions on the award of Studentships, and will have no influence on the success of your application. It will only be shared outside of this group in an anonymised and aggregated form. You will be ask to complete the form by the University to which you apply.

Applications are open

To apply for this studentship please send a CV and cover letter to