锰氧化细菌的分离鉴定及其锰氧化特性的分析

利用选择性培养基对锰矿样品进行分离、筛选, 得到一株高效锰氧化细菌(MN1405)。经形态特征、生理生化特征以及16S rRNA 基因序列分析, 将菌株MN1405 鉴定为Arthrobacter echigonensis。在培养条件下, MN1405 对培养基中的锰离子去除率可达93.38%, 且其培养所获得的培养液也具有良好的除锰效果。     

Oxidation of Manganese and Iron by Leptothrix discophora: Use of N,N,N′,N′-Tetramethyl-p-Phenylenediamine as an Indicator of Metal Oxidation

A new method for the quantification and characterization of manganese-oxidizing activity by spent culture medium of Leptothrix discophora SS-1 was developed. It is based on the formation of the dye Wurster blue from N,N,N′,N′-Tetramethyl-p-phenylenediamine by oxidized manganese generated in the spent medium. The kinetic parameters thus obtained agreed well with data obtained with other methods. It was also possible to demonstrate iron oxidation by spent culture medium. The kinetics of the process and inhibition by enzyme poisons suggest that iron oxidation is enzymatically catalyzed. Probably two different factors are involved in manganese and iron oxidation.     

A note on the enumeration of manganese-oxidizing bacteria in estuarine water and sediment samples

V ojak , P.W.L., E dwards , C. & J ones , M.V. 1985. A note on the enumeration of manganese-oxidizing bacteria in estuarine water and sediment samples. Journal at Applied Bacteriology 59, 375–379.
Media for the enumeration of manganese-oxidizing bacteria in estuarine water and sediment samples were compared. A peptone/yeast extract medium containing manganese sulphate and 30% (v/v) sea salts solution gave the highest percentage of manganese-oxidizers and high total viable counts. A survey of estuarine (River Tamar) and marine (English Channel) sites indicated that manganese-oxidizing bacteria comprise a significant but variable proportion (11–85%) of the total bacterial count.     

The abundance and biological activity of manganese-oxidizing bacteria and Metallogenium-like morphotypes in Lake Washington, USA

The distribution of bacteria, ATP, Metallogenium morphotypes and manganese-oxidizing activities were studied in Lake Washington, Seattle, WA, U.S.A. In accordance with earlier studies, we have found that Metallogenium morphotypes show a stable seasonal distribution in Lake Washington. We have used ⁵⁴Mn(II) tracer studies coupled with poisoned and no-oxygen controls to demonstrate that biological manganese oxidation was not linked to the numbers of Metallogenium morphotypes. The data suggest that these morphotypes do not contribute significantly to the biological oxidation of manganese in Lake Washington.     

Distribution of iron- and manganese-oxidizing bacteria in the bottom sediments of Lake Baikal

The specific features of the distribution, abundance, and taxonomic diversity of bacteria oxidizing iron and manganese in the bottom sediments sampled from different areas of Lake Baikal are studied. These bacteria are widespread in Baikal bottom sediments. Cultivated iron- and manganese-oxidizing microorganisms are ascribed to six genera: Metallogenium, Leptothrix, Siderocapsa, Naumaniella, Bacillus, and Pseudomonas. The surface layers of the ground and the border between oxidized and reduced sediments serve as ecological niches for iron- and manganese-oxidizing microorganisms. Redox conditions of the environment and the availability of dissolved forms of iron and manganese, as well as of organic matter, which are controlled by the conditions of sedimentation in the lake, are the main factors affecting the abundance and distribution of iron bacteria.     

The Importance of the Manganese-Oxidizing Microorganism Metallogenium personatum for the Retention of Manganese in the Wahnbach Reservoir

The retention of manganese in the water of the Wahnbach reservoir was determined in mass balance calculations. The retention properties for manganese drastically decreased after the phosphorus elimination plant was taken into service. Processes controlling the distribution and mobility of manganese in the reservoir were based on the results of tests conducted to evaluate the role of the microorganism Metallogenium personatum. A substantial retention of manganese in the Wahnbach reservoir was found to be dependent on the presence of this planktonic manganese-oxidizing bacterium. The test results clearly indicate the importance of Metallogenium spec. as catalyst in the removal and oxidation of dissolved Mn(II).     

Oxidation of Manganese and Iron by Leptothrix discophora: Use of N,N,N',N'-Tetramethyl-p-Phenylenediamine as an Indicator of Metal Oxidation

A new method for the quantification and characterization of manganese-oxidizing activity by spent culture medium of Leptothrix discophora SS-1 was developed. It is based on the formation of the dye Wurster blue from N,N,N',N'-Tetramethyl-p-phenylenediamine by oxidized manganese generated in the spent medium. The kinetic parameters thus obtained agreed well with data obtained with other methods. It was also possible to demonstrate iron oxidation by spent culture medium. The kinetics of the process and inhibition by enzyme poisons suggest that iron oxidation is enzymatically catalyzed. Probably two different factors are involved in manganese and iron oxidation.     

广西湖润锰矿床的共生生金菌的分离与鉴定

从锰矿床中分离出一种氧化锰的细菌──共生生金菌,该菌嗜温、好氧,是一种化能有机营养型细菌,其适宜于pH6~8的环境中生长,生长具有周期性,与锰作用也表现出阶段性,是氧化锰的主要生物因素。     

Portraying manganese biofilms via a merger of EPR spectroscopy and cathodic polarization

Microbial biofilms on stainless steel surfaces exposed to water from a freshwater pond were dominated by manganese-oxidizing bacteria, as initially diagnosed by microscopy and elemental analysis. The application of electron paramagnetic resonance (EPR) spectroscopy revealed conspicuous sextet (six-line) patterns that intensified with immersion time, implying the gradual accumulation of Mn(II) in the biofilms. Correspondingly, cathodic polarization designated the manganese oxide (MnO_x) reduction peak in the form of a distinctive ‘nose’, which grew increasingly more negative with biofilm growth. The progressive expansion of cathodic current densities and the concurrent area-under-the-curve also allowed the quantification of microbially mediated MnO_x deposition_. Furthermore, the merger of EPR and cathodic polarization techniques yielded key insights, in tandem with Mn speciation data, into the pathways of microbial manganese transformations in biofilms, besides providing meaningful interpretations of prevailing literature. Accordingly, the natural freshwater biofilm was inferred as one supporting a complete manganese cycle encompassing multiple redox states.     

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.     

pH Influences the Distribution of Microbial Rock-Weathering Phenotypes in Weathered Shale Environments

Rock varnish is a darkly pigmented coating rich in manganese oxides. Though microbes inhabit varnish deposits, it is unclear whether they are involved in varnish formation. The fungal communities of rock varnish and adjacent rock sites with no visible varnish deposits were examined. Microcolonial fungi were identified at all sampling sites, and were associated with manganese oxides in patches of incipient varnish at non-varnish sites. Fungi were closely related to manganese-oxidizing genera and seventeen isolates oxidized manganese in culture, producing six distinct manganese-oxide morphologies. Our results indicate that microcolonial fungi may play a crucial role in rock varnish formation. Supplemental materials are available for this article. Go to the publisher's online edition of Geomicrobiology Journal to view the free supplemental file.     

Production of Metallogenium-like particles by heterotrophic manganese-oxidizing bacteria collected from a lake

As a model of chemically stratified structure of environment typical to the chemocline of lakes, a semisolid gradient medium was prepared to cultivate heterotrophic manganese-oxidizing bacteria originally collected from a lake. The bacteria growing under the conditions described produced extracellularly Metallogenium-like particles similar to those which are often detected in the chemocline of lakes. This suggested that the naturally occurring Metallogenium-like particles originated in activities of such heterotrophic manganese-oxidizing bacteria. The manganese oxidation activity usually appeared only at the stationary phase of bacterial growth. The oxidation of Mn²⁺ and the formation of Metallogenium-like particles by the bacteria were observed at neutral or slightly acidic pH. not under alkaline conditions, which is a conspicuous difference from the inorganic oxidation of Mn²⁺ by O₂. Bacterial manganese oxidation was stimulated by bicarbonate (50 or 500 M). An experiment of addition of H₂O₂ to the incubation tubes isolated from atmosphere failed to confirm the availability of externally added H₂O₂ as the electron acceptor, suggesting that the bacterial manganese oxidation required the presence of O₂.     

Microalgal-facilitated bacterial oxidation of manganese

In the presence of unicellular microalgae, bacterial manganese oxidation was increased by up to ten times the rate produced by bacterial oxidation alone. Azide-poisoned controls demonstrated that the manganese-oxidizing bacteria were active in the algal-bacterial oxidation of manganese. Scanning electron microscopy showed that oxide formation occurred in a number of structurally different deposits on the surface of the alga. Studies involving algal cell fractionation showed that bacterial manganese oxidation was facilitated by the algal cell wall, possibly via Mn²⁺ adsorption. Variations in growth conditions had an effect on algal-bacterial oxide formation and composition. High nutrient (yeast extract, peptone and/or sucrose) levels favored microbial growth but lowered oxide formation, whereas optimal levels of manganese oxide formation required minimal media. High concentrations of either organic nutrients or mineral salts promoted manganese carbonate precipitation.     

Formation of manganese oxyhydroxides on the Dead Sea coast by alteration of Mn-enriched carbonates

Manganese enriched carbonates preferentially accumulate in near-shore, shallow water sediments of the Dead Sea. These carbonates are formed by coprecipitation of Mn with authigenic aragonite, as well as by direct precipitation of Mn-carbonate from the pore water of the shallow sediments. The primary source of the Mn that accumulates as carbonates is allochthonous Mn-enriched oxides that are eroded from the nearby coasts and become buried within the near-shore shallow water sediments. Due to the decline in the level of the Dead Sea between 1960–1990, bands of sediments (parallel to the current shoreline) which were previously submerged, became exposed to air and consequently desiccated. We suggest that in order to approach new hydraulic equilibrium in some of those coastal areas, the decline in the level of the lake was followed by a lakeward advance of fresher groundwater from the shallow coastal aquifer. Those fresher waters are characterized by a higher pH than the interstitial brine, and therefore a new state of water-rock interaction is established which results in oxidative alteration of Mn-carbonates to Mn-oxides. In addition, manganese-oxidizing bacteria, shown to be active in water with lower salinity than that of the Dead Sea, may also play a part in oxidation of divalent manganese released from the sediment. As a result, some segments of the Dead Sea coast are characterized by black Mn-enriched sediments that in places form crusts over the surface.     

A comparison of manganese oxidation by growing and resting cells of a freshwater bacterial isolate, strain FMn 1

A bacterial isolate, strain FMn 1, from reservoir sediment oxidized MN2+ when tested in growing culture and resting-cell suspension. The oxidation was biologically mediated and not the result of autoxidation because at a MnSO4 . H2O concentration of 0.05%, the pH remained below 7.5 for the duration of the experiments. The production of manganese oxide was qualitatively and quantitatively demonstrated. The manganese-oxidizing activity of this organism was found to be inducible.     

Fungi and bacteria involved in desert varnish formation

Desert varnish is a coating of ferromanganese oxides and clays that develops on rock surfaces in arid to semi-arid regions. Active respiration but not photosynthesis was detected on varnished rock surfaces from the Sonoran Desert. Light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations, and cultivation experiments indicate that both fungi, primarily dematiaceous hyphomycetes, and bacteria are found on and within desert varnish coatings from the arid regions studied. Some fungi grow as microcolonial fungi (MCF) on rocks, and microscopic observations suggest MCF become incorporated in the varnish coating. SEM-EDAX (energy dispersive X-ray systems) analyses indicate the MCF contain 3 of the characteristic elements of varnish: iron, aluminum, and silicon. In some locations, MCF are also enriched in manganese relative to the rock substratum. Furthermore, some of the dematiaceous hyphomycetes that have been cultivated are able to oxidize manganese under laboratory conditions. It is possible that manganese-oxidizing bacteria, which are found in varnish, also play an important role in varnish formation.     

A multicopper oxidase is essential for manganese oxidation and laccase-like activity in Pedomicrobium sp. ACM 3067

Pedomicrobium sp. ACM 3067 is a budding-hyphal bacterium belonging to the alpha-Proteobacteria which is able to oxidize soluble Mn2+ to insoluble manganese oxide. A cosmid, from a whole-genome library, containing the putative genes responsible for manganese oxidation was identified and a primer-walking approach yielded 4350 bp of novel sequence. Analysis of this sequence showed the presence of a predicted three-gene operon, moxCBA. The moxA gene product showed homology to multicopper oxidases (MCOs) and contained the characteristic four copper-binding motifs (A, B, C and D) common to MCOs. An insertion mutation of moxA showed that this gene was essential for both manganese oxidation and laccase-like activity. The moxB gene product showed homology to a family of outer membrane proteins which are essential for Type I secretion in Gram-negative bacteria. moxBA has not been observed in other manganese-oxidizing bacteria but homologues were identified in the genomes of several bacteria including Sinorhizobium meliloti 1021 and Agrobacterium tumefaciens C58. These results suggest that moxBA and its homologues constitute a family of genes encoding an MCO and a predicted component of the Type I secretion system.     

Microbially mediated redox transformations of manganese (II) along with some other trace elements: a study from Antarctic lakes

The significance of freshwater systems in global manganese cycles is well appreciated. Yet, the polar systems, which encompass the largest freshwater repository in the world, have been least studied for their role in manganese cycling. Here, we present results from a study that was conducted in the brackish water lakes in the Larsemann Hills region (east Antarctica). The rate of in situ manganese oxidation ranged from 0.04 to 3.96 ppb day⁻¹. These lakes harbor numerous manganese-oxidizing bacteria (10⁵ to 10⁶ CFU l⁻¹), predominantly belonging to genera Shewanella, Pseudomonas and an unclassified genus in the family Oxalobacteriaceae. Experiments were conducted with representatives of predominant genera to understand their contribution to Mn cycling and also to assess their metabolic capabilities in the presence of this metal. In general, the total and respiring cell counts were stimulated to a maximum when the growth medium was amended with 10 mM manganese. The addition of manganese promoted the use of d-mannitol, maltose, etc., but inhibited the use of maltotriose, l-serine and glycyl l-glutamic acid. The bacterial isolates were able to catalyze both the redox reactions in manganese cycling. In vitro manganese oxidation rates ranged from 3 to 147 ppb day⁻¹, while manganese reduction rates ranged from 35 to 213 ppb day⁻¹. It was also observed that the maximum stimulation of manganese oxidation occurred in the presence of cobalt (81 ± 57 ppb day⁻¹), rather than iron (37 ± 16 ppb day⁻¹) and nickel (40 ± 47 ppb day⁻¹). Our studies suggest that cobalt could have a more profound role in manganese oxidation, while nickel promoted manganese reduction in polar aquatic systems.     

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.     

Bacterial and archaeal populations associated with freshwater ferromanganous micronodules and sediments

Biology is believed to play a large role in the cycling of iron and manganese in many freshwater environments, but specific microbial groups indigenous to these systems have not been well characterized. To investigate the populations of Bacteria and Archaea associated with metal-rich sediments from Green Bay, WI, we extracted nucleic acids and analysed the phylogenetic relationships of cloned 16S rRNA genes. Because nucleic acids have not been routinely extracted from metal-rich samples, we investigated the bias inherent in DNA extraction and gene amplification from pure MnO₂ using defined populations of whole cells or naked DNA. From the sediments, we screened for manganese-oxidizing bacteria using indicator media and found three isolates that were capable of manganese oxidation. In the phylogenetic analysis of bacterial 16S rRNA gene clones, we found two groups related to known metal-oxidizing genera, Leptothrix of the β-Proteobacteria and Hyphomicrobium of the α-Proteobacteria, and a Fe(III)-reducing group related to the Magnetospirillum genus of the α-Proteobacteria. Groups related to the metal-reducing δ-Proteobacteria constituted 22% of the gene clones. In addition, gene sequences from one group of methanogens and a group of Crenarchaeota, identified in the archaeal gene clone library, were related to those found previously in Lake Michigan sediments.