Toxic cocktails in the environment – linking complex toxicant exposure to specific toxicant impacts in soil microbiota - 14.07.2011

Proposed PhD project:

Toxic cocktails in the environment – linking complex toxicant exposure to specific toxicant

impacts in soil microbiota.

 

Project supervisors: Main-supervisor: Kristian K. Brandt (KU-LIFE). (kkb@life.ku.dk)

Co-supervisors: Jan H. Christensen (KU- LIFE), Peter E. Holm (KU- LIFE).

Project collaborators: Prof. Søren J. Sørensen, Copenhagen High-Throughput Sequencing Facility at University of Copenhagen, Faculty of Science.

 

Background: Remediation and clean-up of contaminated soils represents a grand challenge for modern societies, but also basic science and cleantech business opportunities. Most contaminated sites contain complex mixtures of compounds with variable toxicity and persistence. Hence, studies of such sites require high-resolution multi-analyte chemical techniques and in situ identification of the most toxic compound(s). Soil microbiota play a crucial role for the biogeochemistry of contaminants and

can be used as sensitive indicators of ecosystem recovery during soil remediation. Following exposure to toxicants bacterial communities develop resistance, a process called pollution-induced community tolerance (PICT). However, little is known about the persistence of the developed resistance and the potential for a reverse PICT response once toxicant exposure is reduced.

 

Goals of the Ph.D. project will include the acquisition of high-quality chemical fingerprinting data for mixtures of metals and oil hydrocarbons and corresponding acquisition of toxicological endpoints.

However, the ultimate challenge will be to link complex chemical exposure descriptors to specific impacts in soil microbial communities. Chemical exposure will be quantified using metal-specific biosensors, ICP-MS, GC-MS, LC-MS, and comprehensive two-dimensional GC (GC×GC) combined with chemometrics for data pre-processing and analysis of high dimensionality data. Specific impacts will be determined by community-level resistance profiling ([3 H]leucine incorporation), pyrosequencing of metagenomic 16S rRNA genes and by a battery of soil microbial toxicity tests.

Linkage of exposure and impact data will be explored by multivariate calibration and pattern recognition techniques (e.g. partial least square regression). The candidate will be based in the Genetics and Microbiology Group, Department of Agriculture and Ecology and will be affiliated to the research school RECETO and the Center for Environmental and Agricultural Microbiology.

 

further information can be found on: http://www.life.ku.dk/~/media/Pers/docs/Elitephd_projektbeskrivelse/EnvirChemEcotox_1.ashx