Biogenic Minerals Research Articles

Biomimetic organization of collagen matrices to template bone-like microstructures

The mineralized extracellular matrix (ECM) of bone is essential in vertebrates to provide structure, locomotion, and protect vital organs, while also acting as a calcium and phosphate reservoir to maintain homeostasis. Bone's structure comprises mainly structural collagen fibrils, hydroxyapatite nanocrystals and water, and it is the organization of the densely-packed collagen matrix that directs the organization of the mineral crystallites. Biogenic mineralization occurs when osteoblasts release “mineral bearing globules” which fuse into the preformed collagen matrix, and upon crystallization of this amorphous precursor, the fibrils become embedded with [001] oriented nanocrystals of hydroxyapatite. Our prior work has shown that this nanostructured organization of bone can be reproduced in vitro using the polymer-induced liquid-precursor (PILP) process. In this report, our focus is on using biomimetic processing to recreate both the nano- and micro-structure of lamellar bone. We first applied molecular crowding techniques to acidic, type-I collagen solutions to form dense, liquid crystalline collagen (LCC) scaffolds with cholesteric order. We subsequently mineralized these LCCs via the PILP process to achieve a high degree of intrafibrillar mineral, with compositions and organization similar to that of native bone and with a “lamellar” microstructure generated by the twisting LCC template. In depth characterization of the nano- and micro-structure was performed, including optical and electron microscopy, X-ray and electron diffraction, and thermogravimetric analyses. The results of this work lead us closer to our goal of developing hierarchically structured, collagen-hydroxyapatite composites which can serve as fully synthetic, bioresorbable, load-bearing bone substitutes that are remodeled by the native BRU.

Redistribution of mineral elements in wheat grain when applying the complex enzyme preparations based on phytase

Biogenic minerals play an important role in the whole human nutrition, but they are included in the grain of the phytates that reduces their bioavailability. Whole wheat bread is generally considered a healthy food, but the presence of mineral elements in it is insignificant, because of weak phytate degradation. From all sources of exogenous phytase the most productive are microscopic fungi. To accelerate the process of transition hard mineral elements are mobilized to implement integrated cellulolytic enzyme preparation based on the actions of phytase (producer is Penicillium canescens). Phytase activity was assessed indirectly by the rate of release of phosphate from the substrate. It has been established that the release rate of the phosphoric acid substrate is dependent on the composition of the drug and the enzyme complex is determined by the presence of xylanase. The presented experimental data shows that a cellulase treatment of the grain in conjunction with the β-glucanase or xylanase leading to an increase in phytase activity could be 1.4 - 2.3 times as compared with the individual enzymes. As a result of concerted action of enzymes complex preparation varies topography grain, increase the pore sizes in seed and fruit shells that facilitate the penetration of the enzyme phytase in the aleurone layer to the site of phytin hydrolysis and leads to an increase in phytase activity. In terms of rational parameters of enzymatic hydrolysis, the distribution of mineral elements in the anatomical parts of the grain after processing complex enzyme preparation with the help of X-ray detector EMF miniCup system in a scanning electron microscope JEOL JSM 6390 were investigated. When processing enzyme preparation wheat trend in the distribution of mineral elements, characteristic of grain - the proportion of these elements in the aleurone layer decreases, and in the endosperm increases. Because dietary fiber and phytate found together in the peripheral layers of fiber-rich grains, it is difficult to separate the effects of degradation processes nonstarch polysaccharides and fiberphytate redistribution of polyvalent metal ions. However, studies have shown that phytase - an effective mechanism for regulating mineral nutrient diet. Application of phytase in grain bakery technology will increase the biological value of the product.

Effect of copper upon the actions of sulphate-reducing bacteria isolated from soil contaminated by crude oil and heavy metals / Wpływ miedzi na aktywność bakterii redukujących siarczany wyizolowanych z gleby zanieczyszczonej ropą naftową i metalami ciężkimi

Abstract In the present study, copper tolerance by a mixed culture of sulphate-reducing bacteria (SRB) were evaluated. These sulphidogenic microbial communities were isolated from soils polluted by crude oil, oil-derived products and heavy metals (from selected areas of crude oil mines in south-eastern Poland). Copper tolerance of SRB was tested in modified Postgate C medium with ethanol and lactate as the sole carbon source and copper chloride at concentrations ranging from 0 to 1500 mg/l. Bacterial growth and sulphate reduction were possible between 100 and 1500 mg/l of initial copper concentration. Active sulphate reduction - maximum of 53% was observed in the cultures. Molecular analysis indicated not only the presence of SRB but also other microorganisms that are capable of living in environments contaminated by heavy metals. The high environmental sulphide concentrations produced by SRB lead to the precipitation of any biogenic mineral phases such as metal sulphides. As a result, soluble metal ion concentrations in the microenvironment of SRB are, therefore, extremely low. This process allows SRB to grow in environments containing high levels of toxic metals. Studies on SRB tolerance to heavy metals are extremely important because of the possibility of using this group of microorganisms for the bioremediation and microbial revitalisation of areas contaminated by heavy metals.

Light and SEM observation of opal phytoliths in the mulberry leaf

Biogenic mineral deposits 25–100μm in diameter were observed by microscopic examination of the leaf of mulberry (Morus alba) ‘Ichinose’. Using chemical mapping with scanning electron microscope, the deposits were determined to be opal phytoliths, composed largely of biogenic silica. Phytoliths varied in diameter and were distributed heterogeneously within a leaf. Many phytoliths were observed in close proximity to small veins. Phytolith growth in the mulberry leaf proceeds by deposition of silicon compounds transferred via the network of cell walls.

YREE scavenging in seawater: A new look at an old model

In the ocean, yttrium and the rare earth elements (YREEs) show nutrient-like vertical profiles. Since the YREEs have no manifest biological function, their removal from solution (scavenging) is probably caused by sorption on particles rather than active microbial uptake, yet the exact nature of these particles is uncertain. An existing theoretical model describes scavenging as an equilibrium between complexation with dissolved inorganic ligands and with functional groups on particle surfaces. This model was able to predict input-normalized (i.e., shale-normalized) YREE abundance patterns in seawater without requiring poorly known parameters like particle concentrations or the site densities of functional groups. Employing well-established stabilities of inorganic YREE complexes, while assuming that the sorbent particles are organic with functional groups represented by a mixture of simple monocarboxylic acids, it reproduced some key features of seawater YREE patterns, specifically the characteristic increase of shale-normalized abundance with atomic number and distinctive anomalies of certain trivalent REEs (La and Gd). The familiar negative Ce anomaly of seawater, however, is due to redox reactions that were not explicitly accounted for.In this study, we refined calculations of YREE solution speciation by adding complexation with desferrioxamine B to gauge the influence of strong organic ligands prevalent near the ocean surface. The scavenging model was then inverted by subtracting high-quality YREE abundance patterns, reported for the open ocean, from this solution speciation to yield an average pattern of relative YREE affinities for the sorbent particles. The resulting affinity pattern is compared with patterns of distribution coefficients, derived from laboratory experiments, for YREE sorption on relevant solid phases including hydrated Fe and Mn oxides (HFO/HMO), calcite, and the green macroalga Ulva lactuca as a substitute for marine organic matter. For deep seawater, the best agreement is observed with HMO, which may thus be the dominant carrier of YREEs to the sediment. Since Ce is catalytically oxidized on manganese oxide surfaces, this could have implications for the evolution of the Ce anomaly. Direct comparisons of distribution coefficient patterns with YREE analyses of suspended particles from the Atlantic Ocean also favor HMO, but this may be dictated in one case by the use of a selective leaching method. For shallow seawater, particularly in the Atlantic Ocean, the best agreement is observed with U. lactuca and calcite, although the latter is offset by the low YREE contents of this biogenic mineral. Matches with HFO are generally less convincing. The aforementioned mixture of simple monocarboxylic acids is not a good proxy for the sorptive properties of marine organic matter.

In situ compressibility of carbonated hydroxyapatite in tooth dentine measured under hydrostatic pressure by high energy X-ray diffraction

Tooth dentine and other bone-like materials contain carbonated hydroxyapatite nanoparticles within a network of collagen fibrils. It is widely assumed that the elastic properties of biogenic hydroxyapatites are identical to those of geological apatite. By applying hydrostatic pressure and by in situ measurements of the a- and c- lattice parameters using high energy X-ray diffraction, we characterize the anisotropic deformability of the mineral in the crowns and roots of teeth. The collected data allowed us to calculate the bulk modulus and to derive precise estimates of Young׳s moduli and Poisson׳s ratios of the biogenic mineral particles. The results show that the dentine apatite particles are about 20% less stiff than geological and synthetic apatites and that the mineral has an average bulk modulus K=82.7GPa. A 5% anisotropy is observed in the derived values of Young׳s moduli, with E11≈91GPa and E33≈96GPa, indicating that the nanoparticles are only slightly stiffer along their long axis. Poisson׳s ratio spans ν≈0.30–0.35, as expected. Our findings suggest that the carbonated nanoparticles of biogenic apatite are significantly softer than previously thought and that their elastic properties can be considered to be nearly isotropic.

Enrichment of bakery products with biogenic minerals

The paper presents the study of the mineral composition of bakery products balance, production of biogenic minerals. A method of production of biogenic metals Mg and Mn colloids suspensions during electric sparkle dispersion in water has been presented. Physicochemical properties of received colloids suspensions have been defined. The possibility of integrated colloid suspensions of biogenic metals Mg and Mn for use in the baking industry has been studied. It is proved that the use of suspensions of colloids of biogenic metals Mg and Mn has reduced the duration of proofing dough pieces, improved crumb color of finished products and extended duration of stale. Also, along with the organoleptic and physicochemical indicators mineral content of bakery products has been improved, which enables directional regulation of the chemical composition of finished products.

Low-temperature feldspar and illite formation through bioreduction of Fe(III)-bearing smectite by an alkaliphilic bacterium

Biogenic mineral assemblages that form from circumneutral microbial reduction of iron in smectite have been suggested as biosignatures in the geological record. However, mineralogical transformation of smectite mediated by microbes under extreme pH condition is still poorly known. The objective of this study was to understand the reduction capacity of structural Fe(III) in iron-rich smectite (nontronite, NAu-2) by a novel anaerobic alkaliphile (strain CCSD-1) isolated from the deep subsurface, and associated mineralogical changes. The experiments with CCSD-1 were conducted in a growth medium containing the electron shuttle anthraquinone-2,6-disulfonate (AQDS) at pH9.4. The Fe(II) concentration was monitored over the course of the experiment via wet chemistry, and unreduced and reduced nontronites were characterized with X-ray diffraction (XRD), and scanning and transmission electron microscopy (SEM and TEM). The results indicate that strain CCSD-1 utilizes proteinaceous substrates (yeast extract and tryptone) to reduce structural Fe(III) in smectite with the maximum reduction extent of 26.2%. Mineralogical analysis confirmed that biogenic plagioclase (Na–Ca feldspar) and illite were formed after bioreduction. Our work shows that the interaction between alkaliphile and iron-bearing smectite could account for low-temperature feldspar and illite formation and these minerals may be used as biosignatures in sedimentary rocks.

Orbital detection and implications of akaganéite on Mars

The martian surface bears the mineralogical record of ancient sub-surface and surface aqueous alteration environments. While most of the chemical alteration produced phyllosilicates, hydrated sulfates and chlorides, other less common compounds provide key constraints on localized geochemical settings, and help refine the geological evolution of the planet. Using orbital imaging spectroscopy data, we report the detection of the iron chlorine hydroxide akaganéite (β-FeOOH,Cl) at several locations of Mars. Akaganéite is known to form in highly saline and chlorinated aqueous environments, and its occurrence in at least three basins of Mars suggests the existence of near-marine (lagoon-like) evaporitic settings early in Mars’ history. As a frequently biogenic mineral, the in-depth study of akaganéite and its relationship with other minerals will also provide an additional benchmark for the assessment of pre-biotic to biotic activity on Mars.

Integration of an anti-tumor drug into nanocrystalline assemblies for sustained drug release.

Delicate mesoscopic architectures, bearing complex forms with multiple hierarchy levels, lead to significant functions in biogenic minerals. Herein, a bio-inspired approach was developed to fabricate comet-shaped assemblies of an anti-tumor drug - 10-hydroxycamptothecin (HCPT). The anti-solvent co-precipitation of HCPT and the excipient - PEG-b-PLGA - within the emulsifier leads to the immediate nucleation of comet bundles, followed by a secondary nucleation to generate the comet head, which is an assembly of nanofibers aligned almost in parallel. The continuous manufacturing furnishes drug-excipient hybrid particles with high drug-loading and a sustained drug release profile. This simple and efficient bio-inspired approach led to a promising sustained local drug delivery system, and could be extended to the fabrication of other functional organic materials bearing mesoscopic structural units.

Intracrystalline inclusions within single crystalline hosts: from biomineralization to bio-inspired crystal growth

A review of the inclusion of organic matter within single crystalline hosts: from biogenic minerals to bio-inspired nanohybrid single crystal composites.

Equilibrium conformational ensemble of the intrinsically disordered peptide n16N: linking subdomain structures and function in nacre.

n16 is a framework protein family associated with biogenic mineral stabilization, thought to operate at three key interfaces in nacre: protein/β-chitin, protein/protein, and protein/CaCO3. The N-terminal half of this protein, n16N, is known to be active in conferring this mineral stabilization and organization. While some details relating to the stabilization and organization of the mineral are known, the molecular mechanisms that underpin these processes are not yet established. To provide these molecular-scale details, here we explore current hypotheses regarding the possible subdomain organization of n16N, as related to these three interfaces in nacre, by combining outcomes of Replica Exchange with Solute Tempering molecular dynamics simulations with NMR experiments, to investigate the conformational ensemble of n16N in solution. We verify that n16N lacks a well-defined secondary structure, both with and without the presence of Ca(2+) ions, as identified from previous experiments. Our data support the presence of three different, functional subdomains within n16N. Our results reveal that tyrosine, chiefly located in the center of the peptide, plays a multifunctional role in stabilizing conformations of n16N, for intrapeptide and possibly interpeptide interactions. Complementary NMR spectroscopy data confirm the participation of tyrosine in this stabilization. The C-terminal half of n16N, lacking in tyrosine and highly charged, shows substantive conformational diversity and is proposed as a likely site for nucleation of calcium carbonate. Finally, dominant structures from our predicted conformational ensemble suggest the presentation of key residues thought to be critical to the selective binding to β-chitin surfaces.

Self-similar mesostructure evolution of the growing mollusc shell reminiscent of thermodynamically driven grain growth.

Significant progress has been made in understanding the interaction between mineral precursors and organic components leading to material formation and structuring in biomineralizing systems. The mesostructure of biological materials, such as the outer calcitic shell of molluscs, is characterized by many parameters and the question arises as to what extent they all are, or need to be, controlled biologically. Here, we analyse the three-dimensional structure of the calcite-based prismatic layer of Pinna nobilis, the giant Mediterranean fan mussel, using high-resolution synchrotron-based microtomography. We show that the evolution of the layer is statistically self-similar and, remarkably, its morphology and mesostructure can be fully predicted using classical materials science theories for normal grain growth. These findings are a fundamental step in understanding the constraints that dictate the shape of these biogenic minerals and shed light on how biological organisms make use of thermodynamics to generate complex morphologies.

New insights into the early stages of silica-controlled barium carbonate crystallisation.

Recent work has demonstrated that the dynamic interplay between silica and carbonate during co-precipitation can result in the self-assembly of unusual, highly complex crystal architectures with morphologies and textures resembling those typically displayed by biogenic minerals. These so-called biomorphs were shown to be composed of uniform elongated carbonate nanoparticles that are arranged according to a specific order over mesoscopic scales. In the present study, we have investigated the circumstances leading to the continuous formation and stabilisation of such well-defined nanometric building units in these inorganic systems. For this purpose, in situ potentiometric titration measurements were carried out in order to monitor and quantify the influence of silica on both the nucleation and early growth stages of barium carbonate crystallisation in alkaline media at constant pH. Complementarily, the nature and composition of particles occurring at different times in samples under various conditions were characterised ex situ by means of high-resolution electron microscopy and elemental analysis. The collected data clearly evidence that added silica affects carbonate crystallisation from the very beginning (i.e. already prior to, during, and shortly after nucleation), eventually arresting growth on the nanoscale by cementation of BaCO3 particles within a siliceous matrix. Our findings thus shed light on the fundamental processes driving bottom-up self-organisation in silica-carbonate materials and, for the first time, provide direct experimental proof that silicate species are responsible for the miniaturisation of carbonate crystals during growth of biomorphs, hence confirming previously discussed theoretical models for their formation mechanism.

Particle Accretion Mechanism Underlies Biological Crystal Growth from an Amorphous Precursor Phase

Many biogenic minerals are composed of aggregated particles at the nanoscale. These minerals usually form through the transformation of amorphous precursors into single crystals inside a privileged space controlled by the organism. Here, in vitro experiments aimed at understanding the factors responsible for producing such single crystals with aggregated particle texture are presented. Crystallization is achieved by a two‐step reaction in which amorphous calcium carbonate (ACC) is first precipitated and then transformed into calcite in small volumes of water and in the presence of additives. The additives used are gel‐forming molecules, phosphate ions, and the organic extract from sea urchin embryonic spicules ‐ all are present in various biogenic crystals that grow via the transformation of ACC. Remarkably, this procedure yields faceted single‐crystals of calcite that maintain the nanoparticle texture. The crystals grow predominantly by the accretion of ACC nanoparticles, which subsequently crystallize. Gels and phosphate ions stabilize ACC via a different mechanism than sea urchin spicule macromolecules. It is concluded that the unique nanoparticle texture of biogenic minerals results from formation pathways that may differ from one another, but given the appropriate precursor and micro‐environment, share a common particle accretion mechanism.

Electron Transfer from Humic Substances to Biogenic and Abiogenic Fe(III) Oxyhydroxide Minerals

Microbial humic substance (HS) reduction and subsequent abiotic electron transfer from reduced HS to poorly soluble Fe(III) (oxyhydr)oxides, a process named electron shuttling, significantly increases microbial Fe(III) mineral reduction rates. However, the importance of electron shuttling in nature and notably the electron transfer from HS to biogenic Fe(III) (oxyhydr)oxides have thus far not been determined. In this study, we have quantified the rate and extent of electron transfer from reduced and nonreduced Pahokee Peat humic acids (PPHA) and fresh soil organic matter (SOM) extracts to both synthetic and environmentally relevant biogenic Fe(III) (oxyhydr)oxides. We found that biogenic Fe(III) minerals were reduced faster and to an equal or higher degree than their abiogenic counterparts. Differences were attributed to differences in crystallinity and the association of bacterial biomass with biogenic minerals. Compared to purified PPHA, SOM extract transferred fewer electrons per milligram of carbon and electron transfer was observed only to poorly crystalline ferrihydrite but not to more crystalline goethite. This indicates a difference in redox potential distribution of the redox-active functional groups in extracted SOM relative to the purified PPHA. Our results suggest that HS electron shuttling can also contribute to iron redox processes in environments where biogenic Fe(III) minerals are present.

Proučavanje korovske flore u usevu soje na lokalitetu Sremska Mitrovica i mogućnosti njene kontrole primenom herbicida

For the purpose of studying the weed flora in soybeans and possibilities of its containment through an application of herbicides, research has been conducted in various agroecological conditions, over a two-year period (2011 and 2012.), through work on experimental plots and in the laboratory, on location Sremska Mitrovica (Srem). On the aforementioned locations floristic recordings of the weed flora were conducted, followed by a determination of the plant material, data sorting, a design of floristic tables, charts, pictures, etc. Based on the analysis of life forms, a life form classification was established for the flora in the investigated area. The flora of the investigated area shows a dominant presence of therophytes, and to a much lesser extent of geophytes. On localities Sremska Mitrovica all the established species belong to wide-spread floral elements. Apart from cosmopolites, there is a predominant presence of adventive, subcircumpolar, subeuroasian, and pontosubmediteranean geoelements. The pontosubmediteranean floral element is least represented. By way of an analysis of the ecological humidity indexes, of the chemical reaction of the environment (pH), of the contents of biogenic mineral matter (nitro compounds in particular), of light, and of temperature, a domination of neutrophilic plants (K3) was determined, as well as of eutrophic habitat plants (N4), light indicator taxons (S4), and thermophilic plants (T4) (an indicator of warm habitats). The taxonomic analysis of the weed flora in soy crops grown as part of the two-year experiments in a control test variant on the studied localities has shown the presence of vascular macrophyte species, whose genera and families were determined, as well as the belonging classes, Magnolipsida (Dicotyledone) and Liliopsida (Monocotyledones). The class of Magnolipsida is dominated by the representatives of the families Brassicaceae and Asteraceae, while the representatives of other families are fewer. The class of Liliopsida (Monocotyledones) is dominated by a small number of species from the Poaceae family. The total efficacy of the applied herbicides in the investigated areas is high, and was highly dependent upon the type and combination of herbicides, and to a lesser degree on the year of examination.

Petrography, mineralogy and geochemistry of Balkan coals and their waste products

The samples studied include raw coal from five mines, coal concentrate, coal slurry, associated rock, and waste water. Collodetrinite comprises the dominant portion in raw coals and waste products while collotelinite and telinite/cryptotelenite dominate in the CC. The Ssulphide, particularly that of a syngenetic origin, cannot be completely separated out after coal crushing and flotation. The major minerals are pyrite, quartz, and kaolinite; the minor minerals — illite, muscovite, plagioclase, K feldspar, gypsum, calcite, dolomite, and siderite; and the additional mineral species as gold, sulphur, Fe1.24S0.76, pyrrhotite, galena, hematite, magnetite, hercynite, Cr-spinel, Ti-bearing minerals, biotite, halloysite, zircon, apatite, stilbite, celestine, Mn-calcite, Fe-dolomite, CaFe(CO3)2, ankerite biogenic minerals, volcanic ash, and possible cosmogenic dust are present in the samples as accessory phases. The modes of occurrence of the authigenic minerals suggest that this coal has undergone a series of syngenetic, epigenetic, and exogenic mineralisation. The origin of the epigenetic framboidal pyrite and neoform phases of microbial activity and water treatment is also discussed. The elements Те, S, Cd, U, Cs, V, Mo, W, and Cr are enriched in the coal concentrate compared with worldwide Clarke values of hard coal. Most of the elements have a mixed mode of occurrence. The Br, S, U, and Ge display a strong affinity to organic matter, whereas the Al, K, Si, Rb, Li, Ti, P, and Se display a distinctly inorganic pattern of distribution. Certain of the trace elements (e.g., Sr, Ba, P, Mn, Mo, As, Pb, Sb, Tl, Li, Nb, Be, Y, Ti, Yb, and Cd) are present as impurities in various minerals, whereas other trace elements (e.g., La, Ba, Cu, Re, Pb, Gd, Nd, Sr, Sn, and Cr) are present as discrete phases. It is suggested that the main sources of the trace elements were mineral and mixed sea waters, the basement rocks, and the Sliven U-polymetallic ore deposit. It was also revealed that a number of elements (S, Li, Cs, F, Br, NH−4, NO−3, and V) in the Balkan coals are mobile in water and may pose certain environmental concerns. The coal slurry could be used as a form of fuel.

Biogenic and synthetic high magnesium calcite – A review

Systematic studies on the Mg distributions, the crystal orientations, the formation mechanisms and the mechanical properties of biogenic high-Mg calcites in different marine organisms were summarized in detail in this review. The high-Mg calcites in the hard tissues of marine organisms mentioned generally own a few common features as follows. Firstly, the Mg distribution is not uniform in most of the minerals. Secondly, high-Mg calcite biominerals are usually composed of nanoparticles that own almost the same crystallographic orientations and thus they behave like single crystals or mesocrystals. Thirdly, the formation of thermodynamically unstable high-Mg calcites in marine organisms under mild conditions is affected by three key factors, that is, the formation of amorphous calcium (magnesium) carbonate precursor, the control of polymorph via biomolecules and the high Mg/Ca ratios in modern sea. Lastly, the existence of Mg ions in the Mg-containing calcite may improve the mechanical properties of biogenic minerals. Furthermore, the key progress in the synthesis of high-Mg calcites in the laboratory based on the formation mechanisms of the biogenic high-Mg calcites was reviewed. Many researchers have realized the synthesis of high-Mg calcites in the laboratory under ambient conditions with the help of intermediate amorphous phase, mixed solvents, organic/inorganic surfaces and soluble additives. Studies on the structural analysis and formation mechanisms of thermodynamically unstable biogenic high-Mg calcite minerals may shed light on the preparation of functional materials with enhanced mechanical properties.

Synthesis of Biogenic Mn Oxide and its Application as Lithium Ion Sieve

Geomimetics, taking lessons from natures biogenic mineralization mechanisms, can provide powerful tools for advancing biohydrometallurgical processing. Microbial transformations are largely responsible for the Mn oxides found in nature. In this research biogenic birnessite was produced by a manganese-oxidizing fungus, Paraconiothyrium sp. WL-2, at pH 6.5 under room temperature, and characterized by XRD and TG-DTA. Abiotic (chemically synthesized) acidic birnessite was also prepared hydrometallurgically and subjected to a similar battery of characterization techniques. Following thermal treatment the sorption characteristics of these two materials were compared. The biogenic precursor showed several advantages to produce more effective Li-ion sieve than the chemically synthesized precursor. First, a shorter calcination period was required to produce Li4Mn5O12 without other phases; second, a greater content and higher crystallinity of H4Mn5O12 were obtained from the biogenic precursor. These advantages might be caused by poorer crystallinity and around 20 wt% organic matter in biogenic birnessite. While sorption density of Li+ in mmol/g was basically dependent on contents of H4Mn5O12 phase, the unique morphologies and sorption density were maintained with biogenic precursor even after repetition of sorption/desorption of Li+.