Professor Thomas Clarke, University of East Anglia, School of Biological Sciences
Professor Julea Butt, University of East Anglia, Chemistry
Microbes known as cable bacteria grow vertically in 10cm filaments that span both the anoxic and oxic zones of aquatic sediments. They uniquely make energy by coupling the oxidation of reduced compounds in the anoxic zone to the reduction of oxygen, and so are not restricted by the availability of oxidised compounds in the anoxic zone (1). This likely influences the physiology and metabolism of the local microbial community as well as biogeochemical cycling, but the nature of these effects have not yet been properly investigated. This is because these organisms were only identified by our collaborators at Aarhus university a decade ago. Recently these bacteria were shown to be capable of producing important climate change gases nitrous oxide (N2O) and dimethylsulfide (DMS) and in our pilot studies we show the cable bacterium Candidatus electrothrix to be relatively abundant in diverse iron and sulfur rich coastal sediments throughout the year. These abundances fluctuate over seasons, and are consistent with the relative abundances of other iron and sulfur species (2).
The student will establish methods to enrich and isolate cable bacteria in the UK, supported by our collaborators who are the world experts in this field. They will study the relative abundance of different chemical species in sediments enriched for cable bacteria with sediments that have not been enriched. This will allow the impact of these organisms to be accurately addressed across a range of scientific areas, including changes in distribution of the redox active elemental species such as nitrous oxide and dimethyl sulfoxide and the metagenomic distribution of other micro-organisms (3).
The student will spend several months at the ‘Centre for Electromicrobiology’ at Aarhus university (Denmark) learning to isolate and culture cable bacteria from coastal sediments. At UEA training in environmental analysis of metals and different sulfur species will be provided in order to determine how the sediment composition is affected. They will also learn environmental DNA extraction techniques and metagenomic sequencing methods to determine how the microbiome is affected by the active metabolism of these organisms.
A person with a 2:1 or above in Microbiology or related discipline