Details of Award
NERC Reference : NE/C001109/1
Identification of key enzymes/genes involved in aerobic DMS oxidation by marine bacteria
Grant Award
- Principal Investigator:
- Professor H Schaefer, University of Warwick, Biological Sciences
- Co-Investigator:
- Professor JC Murrell, University of East Anglia, Environmental Sciences
- Grant held at:
- University of Warwick, Biological Sciences
- Science Area:
- Marine
- Atmospheric
- Overall Classification:
- Marine
- ENRIs:
- Global Change
- Biodiversity
- Science Topics:
- Environmental Microbiology
- Biogeochemical Cycles
- Ocean - Atmosphere Interact.
- Climate & Climate Change
- Abstract:
- Dimethyl sulfide (DMS) is an organic sulfur compound that has important implications for the regulation of the global climate. It is produced from dimethylsulfoniopropionate (DMSP), which is a metabolite of many species of marine algae. DMS is volatile and so is emitted from the ocean to the atmosphere. It represents the major input of organic sulfur into the atmosphere. Here, chemical oxidation of DMS gives rise to sulfur containing aerosols, which have an effect on the temperature of the atmosphere. These aerosols directly reflect heat (from solar radiation) into space, but they also promote cloud formation. Increased cloud cover also leads to more reflection of sunlight (and thus heat) into space. The effect of DMS in the atmosphere is assumed to bring about a net cooling of the Earth. However, up to 90% of the DMS that is produced in the surface ocean is rapidly oxidised by specialised bacteria and so never reaches the atmosphere. Knowledge of what kind of bacteria are responsible for DMS degradation and how this is achieved (ie. which enzymes and genes are involved) would greatly enhance our capacity to understand fluctuations in DMS degradation and to predict how DMS degradation by marine bacteria may be affected by environmental change (eg. global warming). Using genetic (DNA-based) markers for genes encoding key enzymes of DMS degradation, it would be possible to investigate the diversity of DMS degrading bacteria and to find out how the process of DMS degradation is regulated in the marine environment. However, no gene sequences encoding DMS degradation enzymes are known at present. Therefore, we propose to identify and sequence these genes in a number of DMS degrading marine bacteria. A number of species of marine bacteria were isolated previously and were shown to have the capacity to degrade DMS. These will be grown on or in the presence of DMS and the biomass will be analysed by protein gel electrophoresis. These polypeptide patterns will be compared to those obtained after growth on substrates other than DMS. Polypeptides that are only present during growth on DMS will be analysed by mass spectrometry methods. The results of those analyses will be able to directly identify the corresponding genes if the genomic DNA sequence of the bacterium is known (as in the case of Silicibacter pomeroyi) or will provide amino acid sequence information that can be used to develop DNA probes for identification of these genes by molecular biological methods if the genome sequence is unknown. We will clone and sequence these genes from a number of marine bacteria. This will provide a database of sequences which can be used in future studies to recognise homologous genes in the environment using molecular biological techniques. This will allow to progress in understanding DMS degradation in the marine environment.
- NERC Reference:
- NE/C001109/1
- Grant Stage:
- Completed
- Scheme:
- Small Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Small Grants
This grant award has a total value of £30,820
FDAB - Financial Details (Award breakdown by headings)
| Total - Staff | Total - Other Costs | Total - Indirect Costs |
|---|---|---|
| £14,825 | £9,176 | £6,820 |
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