Life in the extreme: microbial growth on volcanic rock
Lead Supervisor: Dr Marcela Hernández García
Location: University of East Anglia, School of Biological Sciences
Duration: 6 weeks
Suitable undergraduate degrees: Environmental Microbiology
Project background
Background
Volcanic deposits represent a unique environment in which to study soil formation. Microbes colonising these environments are particularly interesting as they can grow in these bare systems, where most of the time there are only volcanic rocks. Hernandez’s work on volcanic soils, and that of others, has shown that after lava solidifies, microorganisms can oxidise carbon monoxide (CO) from these environments. They can do this because they contain in their genomes genes encoding for carbon monoxide dehydrogenases (CODHs). Previously, Hernandez examined the diversity of bacteria following a chrono-sequence path (i.e. soils of different ages) on Llaima volcano, Chile, and discovered that a specific class of bacteria (Ktedonobacterales), dominated newly-formed soil. We have also observed similar patterns in other volcanoes, including Calbuco volcano in Chile. Furthermore, King has also observed a similar pattern in Kilauea volcano in the USA (pers. comms.).
In this proposal, we will investigate if the microbial colonisation of volcanic rocks by Ktedonobacterales is also observed in another volcano in Réunion Island. Réunion is an island in
the Indian Ocean and a 5-million-year basaltic volcanic edifice composed of two central shield volcanoes: inactive Piton des Neiges and active Piton de la Fournaise in the southeastern part of the island. The Piton de la Fournaise is one of the most active volcanoes worldwide.
Hypothesis
We hypothesise that microorganisms from Piton de la Fournaise volcano can grow by oxidising atmospheric trace gases, such as CO, and start colonising volcanic rock thus playing a key role in soil formation.
The student will characterise the microbial community using cultivation-independent methods addressing the questions:
i) Is CO-oxidation capacity greatest in early volcanic deposits?
ii) Which microbes are responsible for the oxidation of CO in Piton de la Fournaise volcano?
This research will determine how bacteria can oxidise CO in volcanic soils. Soils have been collected by our collaborator (Dr Mikk Espenberg, University of Tartu, Estonia) and the 16S rRNA genes have been sequenced. The student will be trained by the PI and members of her team and will learn techniques for both lab-based work (gas chromatography measurements, DNA extraction and qPCR of functional genes) as well as in-silico-based work (16S rRNA gene analysis).
Methodology
The sampling sites are from Piton de Bert (-21.2788831, 55.6980607), Mare Longue (-21.3512651, 55.7392276) and Coulée de lave (-21.2866284, 55.7957900) with eruptions during
1401, 1559 and 2007, respectively. Soils were sampled at each site in November 2022. Air and soil temperature was measured with a temperature logger (Comet Systems Ltd., Czech Republic). Volumetric soil water content (m3/m3) and conductivity (dS/m) were recorded using a soil moisture sensor (model GS3, Decagon Devices Inc., Pullman, USA) so significant metadata are available for this study.
The student will prepare microcosms incubations and learn interdisciplinary techniques including qPCR, gas-chromatography measurements, amplicon-based sequencing, and bioinformatics. The student will also perform trace gas consumption and qPCR of functional genes, for example coxL, as described previously.
Deliverables: Identify bacteria and their functional guilds along succession, leading to publications in high quality microbial ecology journals.
References:
1. Hernández M, et al. 2020a. Microorganisms 8:1880.
2. Hernández M, et al. 2020b. Pedosphere. 30: 126-134.
3. King GM. 2003. Appl. Environ. Microbiol. 69: 4067-4075.
4. Weber CF, King GM. 2010. Environ. Microbiol. 12: 1855-1867.
5. King CE, King GM. 2014. Int. J. Syst. Evol. Microbiol. 64: 1244-1251.
6. Islam ZF, et al. 2019. ISME J. 13: 1801-1813.
7. Roult et al. 2012. J. Volcanol. Geotherm. Res. 241–242: 78–104
8. Albert, S. et al. 2020. J. Volcanol. Geotherm. Res, 401: 106974.
This is a two tiered application process. Initial applicant selection will be made by project supervisors and a further interview (online) will be conducted by UEA members of ARIES on the afternoon of Tuesday 13th June.