Metal quotas of plankton in the equatorial Pacific Ocean

Composition of metals in suspended particulate matter of Alfonso basin, southern Gulf of California

“…The comparison of normalized M P concentration values hereby recorded with those reported for the elemental composition of suspended material (Kuss and Kremling, 1999;Yiğiterhan et al, 2011) for several natural populations and phytoplankton culture systems (Bruland, 1983;Morel and Hudson, 1985;Ho et al, 2003Ho et al, , 2004bHo et al, , 2009Ho et al, , 2010Twining et al, 2004Twining et al, , 2010Twining et al, , 2011Ho, 2006) reveal substantial differences, which apparently can be attributed neither to environmental fluctuations in the concentration of dissolved metals nor to the physiological requirements of existing groups (Sunda, 1989;Sterner and Elser, 2002;Glass and Orphan, 2012;Nuester et al, 2012). We suggest that the increase in normalized M P values observed in the aphotic layer in the Alfonso basin mainly results primarily from the dominance of mineral particles over the biological component that remains after remineralization, which make a large proportion of the sinking material (Silverberg et al, 2006;Aguirre-Bahena, 2007;Silverberg et al, 2007).…”

Prokaryotic cells separated from sediments are suitable for elemental composition analysis

“…However, using both approaches would allow comparison of element distributions across broad components of a microbial community with those of the individual cells comprising the biomass. This method will help quantify the multi-element stoichiometric envelope within which microbes operate (Sterner and Elser 2002;Ho et al 2003;Twining et al 2011;Cameron et al 2012;Nuester et al 2012). It will also allow comparisons of microbial elemental compositions with those of their environment to determine their mutual influence ).…”

“…It is especially difficult to determine the microbial content of metals such as Fe, Ni, Cu, Zn, and Mo, which are also found in sediment. However, these elements need to be quantified to extend the stoichiometric analysis beyond the standard "Redfield C:N:P ratio" to a broader suite of elements of biological importance (Twining et al 2011;Nuester et al 2012). Removing the sediment contribution from elemental analyses of microbial communities, extremophilic or otherwise, requires either effective isolation of cells from complex mineral matrices Steenbergh et al 2013) or in situ microscopic analyses (Heldal et al 2003, Steenbergh et al 2013.…”

Urea and nickel utilization in marine cyanobacteria as evaluated by incubation, proteomic, and uptake techniques

“…Utilization estimated from a typical 15 pgC cell -1 estimated from [33] and verified by [34] assuming typical cell volume of 130 µm 3 . Metal (M) quota ratios defined as mol M/mol C are taken from diatom specific equatorial pacific field measurements given in [1]; Ni/C=3.7x10 -6 , Fe/C=12.3x10 -6 . Bold and shaded cells denote suspected Ni-limitation assuming 20x10 -9 M total Ni and conservatively estimating 50% bioavailability.…”

“…Diatom biomass and associated trace element composition dominate significant oceanic regions [1]. These algae respond rapidly to nutrient inputs such as nitrogen and phosphorous, but perhaps more importantly to trace metals such as iron which is the limiting nutrient in much of the open ocean [2].…”