Rapid depletion of dissolved organic sulphur (DOS) in freshwaters
Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid
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Yn: Biogeochemistry, Cyfrol 149, Rhif 1, 02.05.2020, t. 105-113.
Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid
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T1 - Rapid depletion of dissolved organic sulphur (DOS) in freshwaters
AU - Brailsford, F. L.
AU - Glanville, H. C.
AU - Wang, D.
AU - Golyshin, P. N.
AU - Johnes, P. J.
AU - Yates, C. A.
AU - Jones, D. L.
PY - 2020/5/2
Y1 - 2020/5/2
N2 - Sulphur (S) is a key macronutrient for all organisms, with similar cellular requirements to that of phosphorus (P). Studies of S cycling have often focused on the inorganic fraction, however, there is strong evidence to suggest that freshwater microorganisms may also access dissolved organic S (DOS) compounds (e.g. S-containing amino acids). The aim of this study was to compare the relative concentration and depletion rates of organic 35S-labelled amino acids (cysteine, methionine) with inorganic S (Na235SO4) in oligotrophic versus mesotrophic river waters draining from low nutrient input and moderate nutrient input land uses respectively. Our results showed that inorganic SO42− was present in the water column at much higher concentrations than free amino acids. In contrast to SO42−, however, cysteine and methionine were both rapidly depleted from the mesotrophic and oligotrophic waters with a halving time < 1 h. Only a small proportion of the DOS removed from solution was mineralized and excreted as SO42− (< 16% of the total taken up) suggesting that the DOS could be satisfying a demand for carbon (C) and S. In conclusion, even though inorganic S was abundant in freshwater, it appears that the aquatic communities retained the capacity to take up and assimilate DOS.
AB - Sulphur (S) is a key macronutrient for all organisms, with similar cellular requirements to that of phosphorus (P). Studies of S cycling have often focused on the inorganic fraction, however, there is strong evidence to suggest that freshwater microorganisms may also access dissolved organic S (DOS) compounds (e.g. S-containing amino acids). The aim of this study was to compare the relative concentration and depletion rates of organic 35S-labelled amino acids (cysteine, methionine) with inorganic S (Na235SO4) in oligotrophic versus mesotrophic river waters draining from low nutrient input and moderate nutrient input land uses respectively. Our results showed that inorganic SO42− was present in the water column at much higher concentrations than free amino acids. In contrast to SO42−, however, cysteine and methionine were both rapidly depleted from the mesotrophic and oligotrophic waters with a halving time < 1 h. Only a small proportion of the DOS removed from solution was mineralized and excreted as SO42− (< 16% of the total taken up) suggesting that the DOS could be satisfying a demand for carbon (C) and S. In conclusion, even though inorganic S was abundant in freshwater, it appears that the aquatic communities retained the capacity to take up and assimilate DOS.
KW - Dissolved organic matter
KW - DOS processing
KW - Nutrient cycling
KW - Radioisotopes
KW - Sulphate
U2 - 10.1007/s10533-020-00669-4
DO - 10.1007/s10533-020-00669-4
M3 - Article
VL - 149
SP - 105
EP - 113
JO - Biogeochemistry
JF - Biogeochemistry
SN - 0168-2563
IS - 1
ER -