Juan Francisco Mujica Alarcon

Microbial community dynamics across chemical interfaces and their role in bioremediation of plumes

PhD research student


Kroto Research Institute
North Campus, University of Sheffield
Broad Lane
S3 7HQ
United Kingdom

Telephone: +44 (0)114 22 25786
Room: Kroto G17

email : jfmujica1@sheffield.ac.uk


Juan received his degree in biology with specialization in Environment and Natural Resources from The Pontifical Catholic University of Chile. During this programme he worked in Ecology studies in the CASEB (Center for Advanced Studies in Ecology and Biodiversity) and in Microbiology and Ecotoxicology in the Microbial Ecology and Environmental Toxicology lab. Juan completed his degree with modules in the University of Nottingham. After this he moved to environmental consultancy, participating in baselines projects and environmental management programmes in Chile, as a limnologic specialist and Field and Project Manager.

Research interests

His PhD research focuses on understanding the environmental controls on microbial dynamics that occur across chemical interfaces between clean and polluted groundwater. Such interfaces exist naturally at the boundary (or “fringe”) of contaminant plumes and are created artificially in heterogeneous aquifers by engineered remediation approaches such as groundwater pump and treatment, which induce mixing between groundwater with different chemistry. This transition zone is marked by steep gradients in organic contaminants, electron acceptors and redox conditions, which vary at different spatial and temporal scales. There is a corresponding variation in the composition and evolution of the indigenous microbial community, which respond to ecological opportunities created by these interfaces. Often, these interfaces have enhanced microbiological activity and biodegradation potential in plumes. This may influence the attachment of the planktonic bacterial community to the attached phase in aquifers and microbial ecological succession in plumes. Understanding these interactions is important because the structural changes in the community and modification of its activity could explain how the microbial community in aquifers responds to pollution inputs or how they adapt to disturbed environments, such as those created by the temporal and spatial development of redox processes in situ. Ultimately, it could influence the potential for biodegradation of organic contaminants in plumes and which bioremediation approaches or metabolic pathways are more effective for in situ restoration. Furthermore, understanding the ecological succession of planktonic-attached bacterial communities in contaminated aquifers may also inform the implementation of restoration concepts such as monitored natural attenuation (MNA) or engineered techniques which attempt to enhance in situ biodegradation in plumes. It will also contribute important fundamental knowledge to the development and application of modelling tools used to predict MNA and design in situ remediation strategies based on biological processes.