Overview

Project Highlights:

  • Pioneering work to study the limits of life
  • Isolation of novel poly-extremophiles
  • Develop expertise in state-of-the-art molecular analyses

Overview:

Extremophilic microorganisms live in some of the most extreme environments on Earth. They can thrive in conditions that were previously deemed inhospitable for life, including extremely high temperatures, high concentration salt solutions, acidity or alkalinity. Extremophilic microorganisms are also thought to have been the first representation of life on early Earth and may have played an important role in the evolution of the Earth’s atmosphere. Studying extremophilic microorganisms is important in order: 1) to characterise the physical and chemical boundaries of life on Earth; 2) to understand how life may have evolved on early Earth; 3) to identify potential enzymes that can be used in biotechnology; 4) to understand potential life elsewhere in the Solar System.

The Danakil Depression is a region of Ethiopia and Eritrea that is unique; several types of extreme environments co-exist. Here, hypersaline and highly acidic hydrothermal springs and pools exist because of sub-surface hydrothermal activity below the ground (Figure 1). Further, the hot, dry climate has led to the evaporation and the precipitation of evaporites, modifying the geochemistry of the surface and sub-surface hydrology.

We have recently shown that poly-extremophiles (extremophiles that can survive more than one extreme) can live within hypersaline acidic hydrothermal springs and the evaporitic deposits found within the depression (unpublished data). We hypothesise that the combined environmental stressors, for example high temperature, acidic pH and saline conditions, may result in novel mechanisms for survival. This PhD will test this hypothesis using a combination of state-of-the-art molecular techniques and microbiology.

Figure 1: Hydrothermal pool in Dallol crater in the northern part of the Danakil Depression. The water is extremely acidic and the coloured surrounding deposits are mainly salts, sulfur and iron crust.

Methodology

To understand how life exists within such an extreme environment both culture-dependent and independent approaches will be used.

The culture-independent approach will involve the extraction of nucleic acids from the environmental samples, using methods that we have previously developed (sequencing will be carried out externally). Bioinformatics analysis will be carried out to determine i) the diversity of the active microbial community within the hydrothermal system; ii) key genes required for survival in such an extreme environment.

The culture- dependent work will involve both aerobic and anaerobic techniques. Using geochemical data obtained from the sample site, media will be developed for the isolation of novel poly-extremophilic microorganisms. Once isolated the microorganisms will be identified and physiological characterised.

Training and Skills

The student would be part of an active environmental microbiology team at the OU consisting of PDRAs, project officers and PhD students. The laboratories contain state-of-the-art equipment and are fully supported by technical support. The student will gain general microbiology training, including cultivation of aerobic and anaerobic microorganisms and nucleic acids extractions. Extensive bioinformatics training will be given by the teams at the OU and Warwick; furthermore, specialised training in metagenomics will be supplied in collaboration with Sophie Nixon (see below). The student will also gain training in geochemical techniques, including sample handing and manipulation, and instrumentation such as Inductively Coupled Plasma- Mass Spectrometer (ICP-MS).

Timeline

Year 1: Perform a literature review and carry out DNA/RNA extractions on samples that have previously been collected from Dallol. In parallel set up the enrichments required for isolation of microorganisms. Initial training in metagenomics.

Year 2: Isolate the microorganisms from the enrichments and characterise. Perform metagenomics analyses and prepare manuscript regarding the diversity and activity of the microbial communities. Present results at a national conference.

Year 3: Submit manuscript regarding mechanisms of survival and adaptation. Write and submit thesis. Present data at an international conference.

Partners and collaboration (including CASE)

Collaborations will include Sophie Nixon (University of Manchester). She is a NERC Research Fellow and an international expert in analysis environmental metagenomics data. As a collaborator, she will offer additional support for the bioinformatics aspect of this project. Barbara Cavalazzi (University of Bologna, Italy) is a geologist. She has extensive expertise regarding the Danakil Depression, environment and therefore will be beneficial for understanding the geological setting of the project. AstraZeneca are potential industrial partners on this project.

Further Details

Students should have a strong background in environmental microbiology and/or molecular biology. The student will join a research team that has extensive experience working with extremophilic microorganisms at the Open University, as well as working with an active team of geochemists.

Please contact Karen Olsson-Francis (k.olsson-francis@open.ac.uk) for further information.

Applications must include:

  • a cover letter outlining why the project is of interest and how your skills are well suited to the project
  • an academic CV containing contact details of three academic references
  • a CENTA application form, downloadable from: http://www.centa.org.uk/media/1202/centa-studentship-application-form.docx
  • and an Open University application form, downloadable from here. Applications should be sent to STEM-EEES-PhD-Student-Recruitment@open.ac.uk by 12pm (noon) on 21st January 2019