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Effect of competitive interactions between manganese and copper on cellular manganese and growth in estuarine and oceanic species of the diatom Thalassiosira 1, 2
Author(s) -
Sunda William G.,
Huntsman Susan A.
Publication year - 1983
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1983.28.5.0924
Subject(s) - manganese , thalassiosira pseudonana , diatom , environmental chemistry , chemistry , seawater , copper , biology , botany , phytoplankton , ecology , nutrient , organic chemistry
We investigated the relationship between growth rate and cellular manganese concentrations for an estuarine diatom Thalassiosira pseudonana (clone 3H) and a related oceanic species Thassiosira oceanica (clone 13‐1). Both species were exposed to a matrix of low manganese and cupric ion activities using ethylenediaminetetraacetic acid (EDTA)‐trace metal ion buffered seawater media. The growth rate of Mn‐limited cultures was related to the cellular concentration of Mn, which in turn was directly related to manganese ion activity and inversely to cupric ion activity. The interaction between manganese and cupric ion activities in controlling cellular manganese and growth rate could be explained quantitatively by competitive binding models in which copper competitively blocked either cellular manganese uptake or the binding of manganese within intracellular pools. Clone 13‐1, isolated from Mn‐poor Sargasso seawater, was able to grow more rapidly at low manganese ion activities than clone 3H, isolated from a eutrophic estuary, provided that cupric ion activity remained below ca. 10 ‒11 mol·liter ‒1 . Adaptation of 13‐1 to growth at low Mn activities appeared to involve two mechanisms: a greater ability for cellular uptake of manganese and a lower cellular manganese requirement (i.e. Mn cell quota) for growth. Comparison of our data with estimates of manganese and cupric ion activities in marine waters suggests that manganese deficiency could be important in controlling phytoplankton growth rate or community composition in some marine waters.