Manganese oxidation in pH and O<sub>2</sub> microenvironments produced by phytoplankton1,2

Richardson, Laurie L.; Aguilar, Carmen; Nealson, Kenneth H.

doi:10.4319/lo.1988.33.3.0352

Cited by 120 publications

(94 citation statements)

References 11 publications

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“…Thus far, firm conclusions are precluded because the experimental quantification of both equilibrium and kinetic parameters for the overall Fe-system in seawater is incomplete. Moreover the assumption of nearly constant pH of seawater is invalidated by the effects of photosynthesis, most notably in micro-environments of algal aggregates and colonies (RICHARDSON, AGUILAR and NEALSON, 1988;DAVIDSON and MARCHANT, 1987;LUBBERS, GIESKES, CASTILHO, SALOMONS and BRIL, 1990).…”

Section: Growth Response Of Individual Phytoplankton Speciesmentioning

confidence: 99%

von Liebig's law of the minimum and plankton ecology (1899–1991)

Baar

1994

Progress in Oceanography

237

132

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-The Law of the Minimum was originally formulated by Justus yon Liebig, as one of the 50 interlinked laws concerned with agriculture. The original writings ofJ. von Liebig often were misinterpreted by his successors. BRAt, rOT (1899) took this one law out of its context and proposed that limitation by nitrogen is a dominant factor in plankton ecology, far beyond its original application to agriculture. This was opposed by NAmANSOrn~ (1908) who suggested instead a dynamic balance of growth and loss terms. Towards validating, or eventually falsifying Brandt's hypothesis, Atkins, Harvey, Cooper and others developed the chemical methods necessary for re-defining ocean nutrient cycling and growth limitation. The major exception to these modem perspectives was the Antarctic Paradox of higla nutrients and low chlorophyll which inspired Gran, Atkins, Harvey and Cooper to pioneer the concept of iron limitation. An exhaustive overview is given of efforts to define Fe in seawater and its controlling effect on in situ plankton growth, for the 1920-1984 period. Somewhat parallel work in the laboratory on single species of algae in chelation-controlled mediahas provided much insight, but is sketched only briefly. Martin and contemporaries developed the chemical methods necessary for defming the ocean chemistry of Fe and its role for in situ growth. These developments are sketched for the 1982-1991 period. Once again the Law of the Minimum and associated bold hypotheses served, albeit briefly, to bring a nutrient element in the forefront of research. This, and the recent awareness of CO 2 as rate limiting factor, underline the conclusion that advances in sciences often hinge on advances in technology, confirming Kta-~ (1962). In this case the new analytical techniques developed by Atkins, Harvey, Cooper, Martin and their associates have proven revolutionary for plankton ecology. Some observations in plankton ecology may be reminiscent of the agricultural Law of the Minimum, but this would not warrant its direct application, beyond its original context and agriculture, to plankton ecology. Rather the net rate of increase ofphytoplankton is the dynamic balance of multiple growth and loss terms, together also determining the biomass at given time and space. 347

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Section: Growth Response Of Individual Phytoplankton Speciesmentioning

confidence: 99%

von Liebig's law of the minimum and plankton ecology (1899–1991)

Baar

1994

Progress in Oceanography

237

132

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“…These microenvironments are induced by either O 2 consumption combined with CO 2 production during respiration (Alldredge and Cohen 1987) or by O 2 production and CO 2 removal with subsequent increase of pH during photosynthesis (Richardson et al 1988;Richardson and Stolzenbach 1995;Epping et al 1998). It was also demonstrated that these changes in redox conditions during photosynthesis, in particular the increase of pH, could lead to the oxidation and precipitation of soluble Mn(II) in both marine and freshwater systems (Richardson et al 1988;Richardson and Stolzenbach 1995;Epping et al 1998). …”

mentioning

confidence: 99%

“…Several studies have shown the existence of microenvironments of O 2 and/or pH gradients associated with microbial mats (Epping et al 1998), marine snow, fecal pellets (Alldredge and Cohen 1987), algal colonies, large algal cells, and phytoplankton aggregates (Richardson et al 1988;Richardson and Stolzenbach 1995). These microenvironments are induced by either O 2 consumption combined with CO 2 production during respiration (Alldredge and Cohen 1987) or by O 2 production and CO 2 removal with subsequent increase of pH during photosynthesis (Richardson et al 1988;Richardson and Stolzenbach 1995;Epping et al 1998).…”

mentioning

confidence: 99%

Effects of photosynthesis on the accumulation of Mn and Fe by Phaeocystis colonies

Schoemann

Wollast

Chou

et al. 2001

Limnology & Oceanography

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The significance of Mn and Fe accumulation by Phaeocystis colonies and its control by photosynthesis were investigated by performing incubation assays with radiotracers ( 54 Mn, 59 Fe and 14 C). Experiments were conducted on pure cultures of Phaeocystis globosa and on natural communities collected during a P. pouchetii bloom in the Balsfjord (subarctic Norwegian fjord) and a P. globosa bloom in the Southern Bight of the North Sea. Results indicate significant accumulation of Mn and Fe in the cultured colonies, as previously shown for Mn. Most of the Mn and Fe accumulation occurred in the mucilaginous matrix of the colonies, and the intracellular assimilation represented only ϳ10% of the total uptake of these trace elements. These experiments demonstrated that photosynthesis largely governed the uptake of Mn by the colonies but only slightly affected the accumulation of Fe. The positive linear relationships observed for the Balsfjord samples between the Mn uptake and the C fixation in the light suggests photosynthetic control of dissolved Mn removal to the Phaeocystis colonies. As had been predicted in earlier studies, the increase in pH and dissolved oxygen observed around and inside the colonies during the photosynthetic activity of the cells could significantly decrease Mn solubility and enhance Mn oxidation rate. However, these changes would not affect significantly the precipitation of Fe according to the thermodynamic considerations. In the highly turbid waters of the North Sea, the removal of Mn and Fe is increased by both inorganic and organic suspended particles, with no significant effect of photosynthesis on the overall uptake.

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“…Since Mn is present in the xylem sap as Mn^^ in unstable complexes with organic anions (Loneragan, 1988) an analogous mechanism to that described for Fe is not needed for Mn. It must also be borne in mind that aquatic phototrophs can, under some circumstances, bring about a photosynthesis-dependent oxidation of Mn(ii) to Mn(iv) by increasing the pH and the Oj concentration near the organism (Arens, 1946;Richardson, Aguilar & Nealson, 1988;cf. Sunda & Huntsman, 1988).…”

Section: Introductionmentioning

confidence: 99%

Predictions of Mn and Fe use efficiencies of phototrophic growth as a function of light availability for growth and of C assimilation pathway

1990

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SUMMARY Iron is involved in many photosynthetic, respiratory and nitrogen assimilation reactions of plants as Fe bound tightly to polypeptides catalysing redox reactions. Manganese is involved as tightly bound Mn in photoreaction II of photosynthesis and in certain superoxide dismutases, while loosely bound Mn2+ is the unique activator of some enzymes, and is an alternative to Mg2+ in activating many enzymes. This paper uses data on the quantitative role of Fe and Mn in catalysts to predict the efficiency with which Fe and Mn are used in C assimilation [mol C assimilated (mol catalytic metal in enzyme)−1 s−1] and the metal cost of C assimilation [mol catalytic metal in enzyme (mol C assimilated)−1 s−1] in photolithotrophic growth in relation to genetic and environmental variables. The genetic variables were the relative content of thylakoid proteins in major taxa (cyanobacteria and red algae, chlorophytes and chromophytes) and smaller‐scale taxonomic differences (various subtypes of C4 metabolism, and C3 metabolism, in terrestrial vascular plants). The environmental variables were the range of photon flux densities in which photolithotrophic growth of O2 evolvers can occur, and the inorganic C supply conditions controlling the repression/de‐repression of the inorganic C concentrating mechanism in cyanobacteria and microalgae. The results of the computations yield the following conclusions. The largest predicted difference in Fe and Mn costs of photolithotrophic growth is related to changes in the photon flux density for growth. The predicted Fe cost increased 50‐fold, and the Mn cost increased 80‐fold, at the lowest extreme of photon flux density compared to the highest found naturally. The increase is partly countered by the larger ratio of light‐harvesting pigments to thylakoid protein complexes assumed for the cells grown at low photon flux densities, although the extent of the increase in photosynthetic unit size is limited by considerations of efficiency of excitation energy transfer. However, the major influences are the higher pigment content in biomass enabling a larger fraction of incident light to the absorbed, and the sub‐maximal specific reaction rates of redox catalysts (whose content is constrained via excitation energy transfer considerations) at very low photon flux densities. A smaller difference, four‐fold or less, in Fe and Mn costs of photolithotrophic growth, is predicted by comparing major taxa (cyanobacteria plus red algae; chlorophytes plus chromophytes) with contrasting ratios of thylakoid redox catalysts. Differences in Fe and Mn costs of growth of less than two‐fold are predicted when the Fe‐ and Mn‐efficient organisms with CO2− concentrating mechanisms (C4 land plants; algae with active inorganic C influx) and high requirements for ATP relative to NADPH, are compared with organisms relying on CO2 diffusion from air or air‐equilibrated solutions and C3 biochemistry. These predictions of variations in Fe and Mn costs of photolithotrophy have implications for the ecology of phototrophs.

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Manganese oxidation in pH and O₂ microenvironments produced by phytoplankton1,2

Cited by 120 publications

References 11 publications

von Liebig's law of the minimum and plankton ecology (1899–1991)

von Liebig's law of the minimum and plankton ecology (1899–1991)

Effects of photosynthesis on the accumulation of Mn and Fe by Phaeocystis colonies

Predictions of Mn and Fe use efficiencies of phototrophic growth as a function of light availability for growth and of C assimilation pathway

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Manganese oxidation in pH and O2 microenvironments produced by phytoplankton1,2

Cited by 120 publications

References 11 publications

von Liebig's law of the minimum and plankton ecology (1899–1991)

von Liebig's law of the minimum and plankton ecology (1899–1991)

Effects of photosynthesis on the accumulation of Mn and Fe by Phaeocystis colonies

Predictions of Mn and Fe use efficiencies of phototrophic growth as a function of light availability for growth and of C assimilation pathway

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Manganese oxidation in pH and O₂ microenvironments produced by phytoplankton1,2