Isoprene (methyl isobutene), a much neglected atmospheric trace gas, is a climate-active gas that is released into the atmosphere in similar quantities to that of methane, making it one of the most abundant trace gases. Large amounts of isoprene are produced by trees but also substantial amounts are released by microorganisms. The consequences on climate are complex. Isoprene can indirectly act as a global warming gas but in the marine environment it is also thought to promote aerosol formation, thus promoting cooling through increased cloud formation. We have been studying bacteria that grow on isoprene. These aerobic bacteria appear to be widespread in the terrestrial and marine environment. Rhodococcus AD45, our model organism, oxidizes isoprene using a soluble diiron centre monooxygenase which is similar to soluble methane monooxygenase. The physiology, biochemistry and molecular biology of Rhodococcus AD45 will be described, together with genome analysis, transcriptome analysis and regulatory mechanisms of isoprene degradation by bacteria. The ecology of isoprene degraders in both the terrestrial and marine environment will be described, together with DNA-Stable Isotope Probing experiments which have enabled us to identify active isoprene degraders in the environment.
Brief Biography of Professor Colin Murrell
Colin Murrell is currently a Professor in Environmental Microbiology in the School of Environmental Sciences and Director of the Earth and Life Systems Alliance (ELSA) on the Norwich Research Park. He has wide ranging research interests centering around the microbiology of atmospheric trace gases such as methane, dimethyl sulfide, methyl halides and isoprene and the metabolism of one carbon compounds (methanol, methylamines, methanesulfonate) in the terrestrial, aquatic and marine environment. Other areas of research include the microbiology of the rhizosphere, sea-surface microlayer, caves, alkaline soda lakes, saltmarshes, cold water corals and cultural heritage microbiology, regulation of gene expression by metals, microbial genomics, metagenomics, bioremediation, biocatalysis and industrial biotechnology. His work over the past 30 years has resulted in over 260 publications and six edited books. He is currently a member of the Editorial Boards of Environmental Microbiology, The ISME Journal, and FEMS Microbiology Letters, and is the Chair-Elect of the 2015 Gordon Research Conference on Applied and Environmental Microbiology. Professor Murrell has also been recently elected to be Vice President of The International Society for Microbial Ecology, as well as a Member of the European Molecular Biology Organisation.