Back to home page (Ian Singleton)

I have a variety of current research interests.

1. Bioremediation of contaminated environments (particularly soils) :

 I have been involved in the commercial bioremediation of pentachlorophenol and diesel contaminated soils and this background has lead into an interest in the bioremediation of 'difficult' organic pollutants e.g. DDT and PAHs. My particular interests lie in novel ways to increase the transformation of recalcitrant pollutants e.g. by increasing the bioavailability of contaminants, and in the toxicity of soils that are biologically treated. For example : bioremediation on a commercial scale does not remove all contaminants presents and a residue is left - what is the toxicity of that residue? What happens to the transformation products produced during bioremediation? Are such products a risk to future use of the soil? Are there physico-chemical ways that can be used to reduce the contaminant residue risk after bioremediation?

2. Novel methods for detecting bioavailability of contaminants to soil microbes.

This is a natural extension of my interests in bioremediation and I'm interested in addressing the questions of how microbes 'see' or access hydrophobic organic pollutants in soil. I am currently developing a novel DNA based method to determine if microbes in soil have accessed pollutants. This assay could also be usefully used to assess the success of  bioremediation on a molecular level e.g. has bioremediation reduced the level of contaminants present which can cause DNA damage to soil dwelling microbes?

3. Pollutant effects on microorganisms and their functions :

The main interest here is in subtle effects of pollutants on microbes. Not all chemicals inhibit the growth of microbes but may cause other damage e.g. DNA damage. The main techniques we are developing to assess this involve the use of  DNA microarrays to assess the effect of selected pollutants on microbial gene expression. Such knowledge can be useful in assessing new chemicals (e.g. pesticides) for potential harmful actions not readily observed in traditional toxicity tests.

4. Use of ozone for control of food pathogens :

A previous and continuing interest in the use of ozone to remediate contaminated soils led to collaboration with a colleague in Newcastle (Dr. Jerry Barnes) and the development of other potential microbial applications for ozone. Ozone is a powerful oxidant and is well known for it's ability to kill microbes. For the past 5 years we have been developing methods to control microbial spoilage of different types of fresh produce using ozone. The results of the work have led to the formation of a University start-up company (see www.bio-fresh.co.uk for further information).