Geomicrobiology of Cave Ferromanganese Deposits: A Field and Laboratory Investigation

Abstract

Unusual ferromanganese deposits are found in several caves in New Mexico. The deposits are enriched in iron and manganese by as much as three orders of magnitude over the bedrock, differing significantly in mineralogy and chemistry from bedrock-derived insoluble residue. The deposits contain metabolically active microbial communities. Enrichment cultures inoculated from the ferromanganese deposits produced manganese oxides that were initially amorphous but developed into crystalline minerals over an 8-month period and beyond; no such progression occurred in killed controls. Phylogenetic analyses of sequences from clone libraries constructed from culture DNA identified two genera known to oxidize manganese, but most clones represent previously unknown manganese oxidizers. We suggest that this community is breaking down the bedrock and accumulating iron and manganese oxides in an oligotrophic environment.     

ELEMENTAL ANALYSIS OF DEPOSITS ON THE ROOTS OF SPARTINA ALTERNIFLORA LOISEL.

Spartina alterniflora, salt marsh cordgrass, is the dominant angiosperm of a large majority of regularly flooded marshes of the Atlantic and Gulf coasts of the United States. In Louisiana, this species often occurs in two distinct zones: a more productive streamside site (adjacent to tidal creeks), and a less productive and sparsely populated inland area. Reddish-brown deposits are present on the roots of streamside Spartina and visually absent from the roots of inland plants. A study of streamside roots using scanning electron microscope and energy dispersive X-ray microanalysis demonstrated that the coatings are restricted to the outer cell wall of the epidermis and are composed primarily of iron. Roots of inland plants have minor iron deposits. Citrate-dithionite extraction of the coatings and subsequent atomic absorption spectrophotometric analysis confirmed these deposits to be iron, although some manganese was present. Approximately 50 times more iron was found on streamside roots compared to roots from inland plants. These results indicate a better developed oxidized rhizosphere associated with streamside Spartina roots than the inland and, hence, the potential for a more favorable environment in which nutrient uptake may proceed.     

Hyphomicrobia and the oxidation of manganesse in aquatic ecosystems

Biogenic manganese deposits from freshwater pipelines in many parts of the world have been examined chemically and microbiologically. For chemical analysis to indicate the nature of the deposit the sampling procedure must ensure that the biogenic deposit is not contaminated by abiogenic material. Hyphomicrobium is abundant in manganese deposits from world-wide location but it is not the only manganese-oxidizing bacterium. The difficulties of assessing the relative importance of hyphomicrobia and other manganese bacteria, and of formulating satisfactory culture media, are discussed.Examination of accredited deposits and laboratory cultures suggests that some hyphomicrobia preferentially oxidize manganese rather than iron.I gratefully acknowledge all those persons and institutions who supplied samples of manganese deposits, and in particular The Hydro-Electric Commission, Tasmania; The Snowy Mountains Authority; Northern Electricity Authority of Queensland; Miss I. J. Powling, State Rivers and Water Supply Commission, Victoria; Melbourne and Metropolitan Board of Works; Mr. G. E. Hollis, New Zealand Electricity Department; Mr. J. Henderson, North-West Gloucestershire Water Boards, and Mrs. K. Ormerod, Norsk Institut for Vannforskning. I thank Mrs. P. M. Scarborough, Mr. R. Buckney for technical assistance, and the Australian Research Grants Committee for a grant.     

Fine structure of in situ microbial iron deposits

The fine structure of iron deposits produced by Leptothrix spp. from two caverns and a surface spring were observed. In the case of Leptothrix pseudovacuolata, the iron occurred as an amorphous deposit within the cell sheath and the cells contained gas vesicles. In the case of the other Leptothrix spp., the iron was deposited within the cell sheath either as a hexagonal or fibrillar matrix. In the case of fibrillar iron deposits, fibrils resembling those of the sheath were found within the cytoplasm of the cells. This suggests that the deposition of iron could have occurred within the cells as well as at the cell surface. In some cases, the fine structure of microbial iron deposits could provide a means of distinguishing biological from abiological iron deposition.     

Metal complexes of lactoferrin and their effect on the intracellular multiplication of Legionella pneumophila

The action of bovine lactoferrin saturated with iron, zinc and manganese on the intracellular multiplication of Legionella pneumophila in HeLa cells has been tested. The results obtained showed that lactoferrin did not influence the invasive efficiency of Legionella. The intracellular multiplication of the bacterium was inhibited by apo-lactoferrin and by lactoferrin saturated with manganese and zinc, whereas lactoferrin saturated with iron enhanced the intracellular growth. Experiments in parallel were performed with iron, manganese and zinc citrate to test the effect due to the metal ions alone. Even in this condition the addition of an iron chelate enhanced the multiplication of Legionella while the manganese chelate produced a certain inhibition.     

Effect of algal growth on the availability of phosphorus,iron and manganese in rice soils

Summary Laboratory experiments were conducted to study the effect of algal growth on the change of (I) pH, (II) available phosphorus and (III) solubility of iron and manganese content in five waterlogged alluvial rice soils of West Bengal, India. The results showed that the algal growth initially caused an increase in the soil pH, which later declined to the original value in some of the soils. The available phosphorus content decreased upto 90 days of their growth and began to increase towards the later period of incubation. The drastic fall of water soluble plus exchaneable manganese content of the soils due to algal growth was accompanied by similar increase in reducible manganese content. No appreciable change in water soluble plus exchangeable ferrous iron content was encountered but theN-NH₄OAC(pH 3) extractable iron due to algal growth progressively decreased with the progress of the incubation period.     

Relationship of trace metals to the alcohol-effect in citric acid synthesis by Aspergillus fonsecaeus

Summary Synthesis of citric acid by Aspergillus fonsecaeus in a basal medium supplemented with trace metals (iron, zinc, copper, and manganese) and methanol has been investigated. Methanol was found to be stimulatory to acid synthesis when manganese or manganese and iron were present. No other mineral tested could be substituted for manganese in the presence of the alcohol. However, comparable yields of citric acid could be obtained if methanol were deleted, the concentration of iron increased and zinc substituted for manganese.This investigation was conducted under a contract with the United States Department of Agriculture, authorized by the Research and Marketing Act, and administered through the Northern Regional Research Laboratory.     

Manganese and iron interactions on their uptake and distribution in soybean (Glycine max (L.) Merr.)

Summary The uptake and distribution of iron and manganese were studied in a manganese-sensitive soybean cultivar (‘Bragg’) grown over a range of supply levels of these nutrients in solution culture. At high (90 and 275 μM) manganese levels, increasing the iron concentration in solution from 2 to 100 μM partially overcame the effects of manganese toxicity. Interactions between manganese and iron occurred for dry matter yields, rate of Mn absorption by the roots, and the proportions of manganese and iron transported to the tops. No interaction was observed for the rate of root absorption of iron. The percentage distribution of manganese in the plant top increased with increasing iron, despite a reduced rate of Mn uptake. On the other hand, iron uptake was independent of solution Mn concentration and increased with increasing solution Fe. Also more iron was retained in the roots at high Mn and/or Fe levels in solution. Concentrations of manganese and iron in roots, stems and individual leaves were affected independently by the manganese and iron supplyi.e. without any interaction occurring between the two elements. In general, the concentration in a plant part was related directly to the solution concentration. Symptoms resembling iron deficiency correlated poorly with leaf Fe concentrations whereas high levels of manganese were found in leaves displaying Mn toxicity symptoms.     

Metallic-Oxide encrustations of the nonprosthecate stalks of naturally occurring populations ofPlanctomyces bekefii

Naturally occurring metallic-oxide encrustations of the multifibrillar stalks of morphotype Ia (Planctomyces bekefii) of theBlastocaulis-Planctomyces group of budding and nonprosthecately appendaged prokaryotes from two sources-a pond in Budapest, Hungary (containing topotypical material) and Gebharts Teich, a fishpond in Austria-have been examined by energy-dispersive X-ray spectroscopy. Some rosettes of morphotype Ib (Planctomyces crassus) also occurred in the Budapest pond; only morphotype Ia was found in Gebharts Teich. Manganese was the major metallic element in the morphotype Ia stalk encrustations from the Budapest pond; iron was not detected. However, morphotype Ib rosettes occurring in the same Budapest pond sampes contained both manganese and iron in their stalk encrustations. Both iron and manganese were present in the morphotype Ia stalk encrustation of rosettes from Gebharts Teich.     

Structural features of manganese precipitating bacteria

Studies of biological communities of the past (and their associated activities) are usually dependent upon preservation of fossil material. With bacteria this rarely occurs because of the absence of sufficient fossilizable cellular material. However, some bacteria deposit metabolic products that can, conditions allowing, be preserved indefinitely. In particular, manganese and iron depositing bacteria have the capacity to form preservable microfossils. In order to better understand these microfossils of the past, we have examined present day morphologies of manganese oxidizing bacteria. These bacteria are highly pleomorphic, depending on the growth medium, the age of the culture, and the extent of manganese oxidation. Transmission electron microscopy indicates that manganese may be deposited either intra-or extra-cellularly. The prognosis of the use of morphological information for the interpretation of ancient and modern manganese deposits is discussed.Proceedings of the Fourth College Park Colloquium on Chemical Evolution:Limits of Life, University of Maryland, College Park, 18–20 October 1978.     

The response of Bacillus subtilis ATCC 21332 to manganese during continuous-phased growth

Summary Bacillus subtilis ATCC 21332 produces an extracellular lipopeptide, called surfactin, a potent surfactant. Using a new technique for cell culturing, continuous phasing with feedback control, the effects of manganese on the growth, and the associated production of surfactin, were investigated. An intimate relationship was revealed between the availability of iron and manganese and the utilization of nitrogen. A critical proportionality of 920/7.7/1.0 (molar basis) of nitrogen to iron to manganese was identified. Increasing the manganese reduced the requirement for nitrogen and resulted in growth under iron limitation. The production of surfactin could be sustained for at least 30 consecutive generations growing under either an iron or nitrogen limitation, but only if manganese was available. The dynamic response of B. subtilis to changes in manganese concentration revealed a non-linear relationship that required several generations to stabilize. Offprint requests to: J. D. Sheppard     

Influence of soil waterlogging on subsequent plant growth and trace metal content

Summary The uptake of trace metals by two plant species (French bean and maize) has been measured on two soils subjected to various waterlogging regimes. Uptake of both manganese and iron was increased due to soil waterlogging, although reoxidation of the soil affected iron more than manganese. Zinc and copper uptake was influenced by a species factor; French bean (Phaseolus vulgaris) showed preferential uptake of zinc, whereas maize (Zea mays) took up copper preferentially. Uptake of cobalt by both species was increased due to waterlogging, following the pattern of manganese.The abilities of these species to take up trace metals from soil followed the pattern predicted by selective extraction of soil for manganese, iron and cobalt, but not for zinc and copper.     

MR Proton Relaxivities of Some Ions, Albumin, and Cholesterol Added to Odontogenic Jaw Cysts

The relaxation rates (1 / T ₁ and 1 / T ₂) in cysts have already been analyzed in terms of materials such as albumin, cholesterol, manganese, iron, and copper. However, the relaxivities of these materials have not been determined yet. In this work, five sets containing the ions, albumin, and cholesterol were prepared by addition of increasing concentration of one material to each set. The relaxation times in these sets were measured by MRI, and the relaxation rates were fitted versus concentrations. The slopes of the fits were used as relaxivities. The (r ₁, r ₂) values of manganese, iron, and copper in mM⁻¹ s⁻¹, and those of albumin and cholesterol in (g/dl)⁻¹ s⁻¹ were found to be (32.64, 89.77), (0.31, 1.19), (0.5, 1.479), (0.01, 0.066) and (0.03, 0.458), respectively. The r ₂/r ₁ ratio ranged from 2.75 to 15.27. Manganese is an efficient relaxer, but iron and copper are poor ones. Albumin and cholesterol are efficient relaxers for only T ₂. The contribution of water associated with native manganese of the cystic fluid to T ₁ was 0.268 s⁻¹, whereas those of water associated with native manganese, albumin, cholesterol, and iron to T ₂ were 0.736, 0.185, 0.092, and 0.076 s⁻¹, respectively. The other contributions were much smaller than 0.076 s⁻¹. Manganese is most likely the compound altering T ₁-weighted images between different jaw cysts, whereas manganese and albumin are most likely the compounds altering the T ₂-weighted images. Present data suggest that such alterations may be used to separate jaw cysts from other jaw masses. The high r ₂/r ₁ suggests that T ₂ is a more convenient parameter than T ₁ for diagnostic use. This work is a part of the PhD thesis of U. Nezih Yilmaz supervised by R. Guner.     

Transformation of iron and manganese in rice soils under different moisture regimes and organic matter applications

Summary Transformation of iron and manganese under three different moisture regimes,viz continuous waterlogged (W₁), continuous saturated (W₂) and alternate waterlogged and saturated (W₃) and three levels of organic matterviz 0, 0.5 and 1.0% in all possible combinations was studied in four soils. The results showed that under waterlogged moisture regime there was a sharp increase in the content of water soluble plus exchangeable manganese accompanied by significant decrease in the content of reducible manganese in all the soils excepting the acidic soil which was very poor in active manganese content. The increase in respect of iron in similar form was, however, very small. The increase in the content of water soluble plus exchangeable manganese as well as iron under the continuous saturated and alternate waterlogged and saturated moisture regimes was always much lower as compared to that under the continuous waterlogged condition. Application of organic matter brought about an increase in the content of water soluble plus exchangeable manganese in all the soils excepting the lateritic one irrespective of moisture regimes but did not cause any change in the content of iron and manganese in insoluble complex. The content of water soluble plus exchangeable iron and of insoluble ferrous iron although recorded some increase due to organic matter application, the increase was not so marked in any of the soils.     

In vivo self-hydroxylation of an iron-substituted manganese-dependent extradiol cleaving catechol dioxygenase

The homoprotocatechuate 2,3-dioxygenase from Arthrobacter globiformis (MndD) catalyzes the oxidative ring cleavage reaction of its catechol substrate in an extradiol fashion. Although this reactivity is more typically associated with non-heme iron enzymes, MndD exhibits an unusual specificity for manganese(II). MndD is structurally very similar to the iron(II)-dependent homoprotocatechuate 2,3-dioxygenase from Brevibacterium fuscum (HPCD), and we have previously shown that both MndD and HPCD are equally active towards substrate turnover with either iron(II) or manganese(II) (Emerson et al. in Proc. Natl. Acad. Sci. USA 105:7347–7352, 2008). However, expression of MndD in Escherichia coli under aerobic conditions in the presence of excess iron results in the isolation of inactive blue-green iron-substituted MndD. Spectroscopic studies indicate that this form of iron-substituted MndD contains an iron(III) center with a bound catecholate, which is presumably generated by in vivo self-hydroxylation of a second-sphere tyrosine residue, as found for other self-hydroxylated non-heme iron oxygenases. The absence of this modification in either the native manganese-containing MndD or iron-containing HPCD suggests that the metal center of iron-substituted MndD is able to bind and activate O₂ in the absence of its substrate, employing a high-valence oxoiron oxidant to carry out the observed self-hydroxylation chemistry. These results demonstrate that the active site metal in MndD can support two dramatically different O₂ activation pathways, further highlighting the catalytic flexibility of enzymes containing a 2-His-1-carboxylate facial triad metal binding motif.     

The solution of manganese oxide by iron sources used in nutrient solutions

Summary The solubility of two manganese oxides was measured in 5×10^–5 to 15×10^–5 M iron and organic acid solutions. The oxides were soluble in all the 15 × 10^–5 M solutions tested except ferric chloride. The amount of manganese dissolved by mixtures of the iron and acid solutions was greater than the sum of that dissolved by the separate solutions. It was suggested that ferric chloride should be used as the iron source in critical studies of the availability of manganese oxides in sand cultures.     

An ultrastructural study of iron and manganese deposition associated with extracellular polymers of pedomicrobium-like budding bacteria

Morphological characteristics of two Pedomicrobium-like budding bacteria are described. A structured surface layer was regularly observed on strain 868. Ruthenium red- and Alcian blue-staining polymers were found on both strains.When either strain was grown in the presence of iron or manganese, the corresponding oxides accumulated on their surfaces. In thin sections iron oxides appeared as fine threads, arrays of particles or dense coatings, depending on the source of iron. Manganese oxides appeared as branching filaments or convoluted ribbons. Both metal oxides stained with ruthenium red. Extraction of the oxides followed by ruthenium red staining revealed that polyanionic polymers previously deposited on the cells were associated with the metals.Treatment of cultures with glutaraldehyde, HgCl₂, or heat, inhibited manganese but not iron deposition, suggesting that iron oxides accumulated by passive, non-biological processes. Manganese oxides apparently accumulated under control of a biological manganese-oxidizing factor. Incomplete inhibition of manganese deposition observed in cell suspensions suggested that, if the oxidizing factor was an enzyme, it was unusually stable.Based on these results, possible mechanisms of iron and manganese deposition in association with extracellular polymers are suggested.     

Synthesis of water-soluble ruthenium porphyrins as DNA cleavers and potential cytotoxic agents

 Three new water-soluble ruthenium porphyrin complexes have been prepared and characterized, one with a cationic ligand, Ru(TMPyP), and two others with anionic ligands, Ru(p–COOH-PP) and Ru(TPPS). These different complexes and their manganese and iron analogues were tested in vivo as potential antitumor agents with mice bearing P388 leukemia cells, but these complexes have no significant antitumor activity. The nuclease activity of Ru(TMPyP) and Ru(p–COOH-PP) was evaluated on supercoiled plasmid DNA after activation by a reducing agent (ascorbate) in the presence of air or by potassium monopersulfate. No significant activity was evidenced for these ruthenium complexes, in contrast with the already known nuclease activity of the manganese and iron derivatives of TMPyP. Received: 15 November 1996 / Accepted: 7 April 1997     

Effect of artificial destratification on iron,manganese, and zinc in the water,sediments, and two species of benthic macroinvertebrates in an Oklahoma lake

Ham's Lake was destratified in the summers of 1977 and 1978 by pumping surface water to the bottom. However, an arm was prevented from mixing by a submerged dam of a former farm pond and remained stratified. The concentration of manganese in the water increased to over 5 000 µg 1^–1 in the hypolimnion of the anoxic arm in summer. Soluble manganese averaged 28% of total concentration. Total iron concentrations were relatively high in the water and sorbed iron values were extremely low in the sediments. Soluble iron averaged 12% of total concentration. Zinc values were low in the water and sediments. Chaoborus punctipennis and Chironomus riparius concentrated iron and zinc and discriminated against manganese. Concentration factors were unaffected by mixing.