Heme b in marine phytoplankton and particulate material from the North Atlantic Ocean | Health & Environmental Research Online (HERO)

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Citation
Tags

HERO ID

2664570

Reference Type

Journal Article

Title

Heme b in marine phytoplankton and particulate material from the North Atlantic Ocean

Author(s)

Honey, DJ; Gledhill, M; Bibby, TS; Legiret, FE; Pratt, NJ; Hickman, AE; Lawson, T; Achterberg, EP

Year

2013

Is Peer Reviewed?

Journal

Marine Ecology Progress Series
ISSN: 0171-8630
EISSN: 1616-1599

Volume

483

Page Numbers

1-+

DOI

10.3354/meps10367

Web of Science Id

WOS:000319680700001

Abstract

Concentrations of heme b, the ironcontaining prosthetic group of many hemoproteins, were measured in 6 species of marine phytoplankton (Dunaliella tertiolecta, Emiliania huxleyi, Thalassio sira weissflogii, T. oceanica, Phaeodactylum tricor nutum and Synechococcus sp. WH7803) that were subjected to variations in iron concentration. Changes in heme b in response to reduced light and nitrate were also ex amined for E. huxleyi and T. oceanica. Results from laboratory cultures were compared with heme b determined in particulate material in the North Atlantic. In cultures, heme b made up 18 +/- 14% (SE) of the total iron pool. Reduced iron and nitrate concentrations resulted in a decreased intracellular heme b concentration, expressed as per mole carbon. Chlorophyll a (chl a) to heme b ratios in E. huxleyi and D. tertiolecta in creased in response to limited light and nutrient availability, but slightly decreased or did not change in the diatoms and the cyanophyte Synechococcus sp. WH7803. The heme b: particulate organic carbon (POC) and chl a: heme b ratios in the North Atlantic were within the range observed in phytoplankton cultures. In the surface mixed layer, decreases in heme b: POC ratios were linked to decreases in nutrient concentrations. Chl a: heme b ratios increased with depth and were thus primarily affected by light availability. Relative relationships between heme b, chl a and POC in the North Atlantic likely represented a change in the ability of cells to undertake cellular processes driven by chl a (light harvesting) and heme b (e.g. electron transport) according to ambient light and nutrient conditions.

Keywords

Hemoprotein; Iron; Electron transport; Cytochrome; Nutrient limitation; Celtic Sea