TY - JOUR
T1 - Vertical and temporal variability of DMSP lyase activity in a coccolithophorid bloom in the northern North Sea
AU - Steinke, Michael
AU - Malin, Gill
AU - Gibb, Stuart W.
AU - Burkill, Peter H.
PY - 2002
Y1 - 2002
N2 - The climatically relevant trace gas dimethyl sulphide (DMS) is produced within the microbial food-web from the algal metabolite dimethylsulphoniopropionate (DMSP). The presence of DMSP lyase isozymes is necessary for this process. Measurements of in vitro DMSP lyase activity (DLA) were conducted in the northern North Sea in June 1999 in order to investigate the vertical and temporal variability of activity in a Lagrangian time-series process study. DLA ranged from 4 to 207 nM h−1, with maximum values close to the surface and between 30 and 50 m depth. DLA increased towards the surface relative to chlorophyll a, as did the non-photosynthetic but photoprotective pigment diadinoxanthin, DMS and dissolved dimethylsulphoxide, a likely oxidation product of DMS. These observations support the hypothesis that DMSP lyases can be affected by irradiance levels, and that DMSP and its cleavage products could be involved in scavenging oxygen radicals; hence, they may function as antioxidants in marine algae. Linear regression analysis of our field data showed reduced biomass of some oligotrich and non-oligotrich ciliates at higher levels of DLA, a finding that could be supportive of a role for phytoplankton DMSP lyases in chemical defence.
AB - The climatically relevant trace gas dimethyl sulphide (DMS) is produced within the microbial food-web from the algal metabolite dimethylsulphoniopropionate (DMSP). The presence of DMSP lyase isozymes is necessary for this process. Measurements of in vitro DMSP lyase activity (DLA) were conducted in the northern North Sea in June 1999 in order to investigate the vertical and temporal variability of activity in a Lagrangian time-series process study. DLA ranged from 4 to 207 nM h−1, with maximum values close to the surface and between 30 and 50 m depth. DLA increased towards the surface relative to chlorophyll a, as did the non-photosynthetic but photoprotective pigment diadinoxanthin, DMS and dissolved dimethylsulphoxide, a likely oxidation product of DMS. These observations support the hypothesis that DMSP lyases can be affected by irradiance levels, and that DMSP and its cleavage products could be involved in scavenging oxygen radicals; hence, they may function as antioxidants in marine algae. Linear regression analysis of our field data showed reduced biomass of some oligotrich and non-oligotrich ciliates at higher levels of DLA, a finding that could be supportive of a role for phytoplankton DMSP lyases in chemical defence.
U2 - 10.1016/S0967-0645(02)00068-1
DO - 10.1016/S0967-0645(02)00068-1
M3 - Article
SN - 1879-0100
VL - 49
SP - 3001
EP - 3016
JO - Deep-Sea Research Part II: Topical Studies in Oceanography
JF - Deep-Sea Research Part II: Topical Studies in Oceanography
IS - 15
ER -