Investigating 'cross-talk' between pathogenic Vibrio and phytoplankton, and implications for human health under climate change.(Ref:4297)

Communication amongst humans allows us to live together in societies. Breakdowns in communication can lead to conflicts and a breakdown of society's structures. However, communication is not limited to humans. Chemical cues and signals, collectively called infochemicals (Fig. 1), are widely used by organisms living on land and sea to communicate between individuals within a species or between different species. For example, albatrosses use a simple chemical cue called DMS (dimethyl sulphide) to track highly productive areas where they forage on zooplankton, squid, fish, and even other birds!

We know from terrestrial ecosystems that climate change stressors such as warming can alter the production and composition of infochemicals with profound negative effects on natural ecosystems. Although this chemical communication currently works well in the ocean, we do not know how marine organisms will communicate under climate change!Phytoplankton, the producers of 50% oxygen we breathe, also use infochemicals to 'talk' to other organisms like microbes, including pathogens such as Vibrio which can be either deterred or attracted towards phytoplankton. Several Vibrio species are human pathogens known to cause waterborne diseases, e.g. Vibrio cholerae responsible for cholera. Climate change is predicted to escalate this problem, posing increased threat to human health.

In this project you will conduct a novel set of experiments underpinning phytoplankton-Vibrio relationships mediated by infochemicals, and explore how climate change induced stressors such as temperature, salinity and precipitation might change phytoplankton-Vibrio interactions. Results will enable us to understand dynamics of phytoplankton-pathogenic marine bacteria interaction, in particular microbes such as Vibrios that represent an emerging disease threat in Europe and other higher latitudes, driven by climate change.

Project Aims and Methods:

The chemically enriched phycosphere (Fig 2), the microscale mucous region enveloping phytoplankton cells, represents the marketplace where interactions between algae and other organisms are controlled by exuded chemicals. In this PhD, you will undertake pioneering research to establish how the association of Vibrio with phytoplankton are controlled by infochemicals. You will work at the interface of ecology, microbiology, chemistry, physiology and climate change research investigating novel questions such as (i) which infochemicals enable positive and negative 'cross-talk' of phytoplankton with selected Vibrio species; (ii) how the entire chemical landscape appears during such associations; and (iii) how such association changes in response to climate-change-induced stressors.

You will work in a highly interdisciplinary international team (UK and Germany) and use different advanced techniques to isolate anti- and pro-Vibrio compounds from phytoplankton cultures and will be trained to use different spectroscopy methods. You will collaborate with Georg Pohnert (Max Plank Institute of Chemical Ecology, Germany) to use latest 'omics' techniques such as untargeted whole cell and single cell metabolomics. You will also perform laboratory incubations to quantify the effect of stressors such as mean temperature rise on the Vibrio-phytoplankton association. Data will be analyzed using multivariate statistics. You will be allowed freedom and flexibility to modify the project design and direction, depending on your interests and skills, within the broad scope of the project's aims.