The biogeochemistry of dimethylsulphoniopropionate (dmsp) in estuarine sediments
The biogeochemistry of dimethylsulphoniopropionate (dmsp) in estuarine sediments
A number of techniques have been developed for the measurement of dimethylsulphoniopropionate (DMSP), dimethylsulphide (DMS) and other sulphur species commonly occurring in estuarine sediments. A reaction-based flow injection analysis (FIA) system that was developed enabled the detection and quantification of trace levels of dissolved sulphide, DMSP and DMS precursors, exhibiting detection limits of ca 10-6 M. An acid reaction step permits the measurement of sulphide species such as S-2. A base hydrolysis was found to be selective toward DMSP, whilst a borohydride reaction widened the range of DMS precursors that could be measured. Gas chromatography was used to determine elemental sulphur and DMS.
A DMSP lyase that cleaves DMSP to DMS and acrylate was purified and characterised from the green macroalga, Enteromorphia intestinalis that is a dominant species on many estuarine intertidal mudflats. The DMSP-lyase is located both as a soluble and detergent-released protein. The molecular weight of the soluble protein was approximately 25.2 kDa. Three hydrophobic variant forms were isolated from the detergent-solubilized activity. The optimum pH value of this DMSP lyase is pH8.0 and the highest measured enzyme activity was observed at 37 °C. However, the influence of NaCl concentration is insignificant. Based on the results of inhibition studies, it is suggested that this DMSP lyase is a metal dependent enzyme but not a thiol-based enzyme. The enzyme activity increased with MgCl2 concentration but decreased with CaCl2 concentration. The Km and Vmax of the soluble DMSP lyase were 0.286 mM and 21.9 nmole DMS/min/mg protein at room temperature respectively.
University of Southampton
Yeh, Chen-Ying
7de8fbcd-5a09-4e30-9e58-22d0d5f3ad66
2000
Yeh, Chen-Ying
7de8fbcd-5a09-4e30-9e58-22d0d5f3ad66
Yeh, Chen-Ying
(2000)
The biogeochemistry of dimethylsulphoniopropionate (dmsp) in estuarine sediments.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
A number of techniques have been developed for the measurement of dimethylsulphoniopropionate (DMSP), dimethylsulphide (DMS) and other sulphur species commonly occurring in estuarine sediments. A reaction-based flow injection analysis (FIA) system that was developed enabled the detection and quantification of trace levels of dissolved sulphide, DMSP and DMS precursors, exhibiting detection limits of ca 10-6 M. An acid reaction step permits the measurement of sulphide species such as S-2. A base hydrolysis was found to be selective toward DMSP, whilst a borohydride reaction widened the range of DMS precursors that could be measured. Gas chromatography was used to determine elemental sulphur and DMS.
A DMSP lyase that cleaves DMSP to DMS and acrylate was purified and characterised from the green macroalga, Enteromorphia intestinalis that is a dominant species on many estuarine intertidal mudflats. The DMSP-lyase is located both as a soluble and detergent-released protein. The molecular weight of the soluble protein was approximately 25.2 kDa. Three hydrophobic variant forms were isolated from the detergent-solubilized activity. The optimum pH value of this DMSP lyase is pH8.0 and the highest measured enzyme activity was observed at 37 °C. However, the influence of NaCl concentration is insignificant. Based on the results of inhibition studies, it is suggested that this DMSP lyase is a metal dependent enzyme but not a thiol-based enzyme. The enzyme activity increased with MgCl2 concentration but decreased with CaCl2 concentration. The Km and Vmax of the soluble DMSP lyase were 0.286 mM and 21.9 nmole DMS/min/mg protein at room temperature respectively.
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Published date: 2000
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Local EPrints ID: 464145
URI: http://eprints.soton.ac.uk/id/eprint/464145
PURE UUID: 56aceb0f-2716-4af3-ab23-cd759b5455cc
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Date deposited: 04 Jul 2022 21:20
Last modified: 16 Mar 2024 19:18
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Author:
Chen-Ying Yeh
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