Division of Molecular Microbiology, College of Life Sciences, University
of Dundee, Dundee DD1 5EH, UK
ABSTRACT
Microbes play key geoactive roles in the biosphere, particularly in the
areas of ...element biotransformations and biogeochemical cycling, metal and
mineral transformations, decomposition, bioweathering, and soil and sediment
formation. All kinds of microbes, including prokaryotes and eukaryotes and
their symbiotic associations with each other and higher organisms,
can contribute actively to geological phenomena, and central to many such
geomicrobial processes are transformations of metals and minerals. Microbes
have a variety of properties that can effect changes in metal speciation,
toxicity and mobility, as well as mineral formation or mineral dissolution
or deterioration. Such mechanisms are important components of natural biogeochemical
cycles for metals as well as associated elements in biomass, soil, rocks and
minerals, e.g. sulfur and phosphorus, and metalloids, actinides and metal
radionuclides. Apart from being important in natural biosphere processes,
metal and mineral transformations can have beneficial or detrimental consequences
in a human context. Bioremediation is the application of biological systems
to the clean-up of organic and inorganic pollution, with bacteria and fungi
being the most important organisms for reclamation, immobilization or detoxification
of metallic and radionuclide pollutants. Some biominerals or metallic elements
deposited by microbes have catalytic and other properties in nanoparticle,
crystalline or colloidal forms, and these are relevant to the development
of novel biomaterials for technological and antimicrobial purposes. On the
negative side, metal and mineral transformations by microbes may result in
spoilage and destruction of natural and synthetic materials, rock and mineral-based
building materials (e.g. concrete), acid mine drainage and associated
metal pollution, biocorrosion of metals, alloys and related substances, and
adverse effects on radionuclide speciation, mobility and containment, all
with immense social and economic consequences. The ubiquity and importance
of microbes in biosphere processes make geomicrobiology one of the most important
concepts within microbiology, and one requiring an interdisciplinary approach
to define environmental and applied significance and underpin exploitation
in biotechnology.
Correspondence Geoffrey Michael Gadd g.m.gadd{at}dundee.ac.uk
•Up-to-date critical review.•Covers concept, definition and application.•Provides directions for future research.
Biosorption is a physico-chemical and metabolically-independent process based on a ...variety of mechanisms including absorption, adsorption, ion exchange, surface complexation and precipitation. Biosorption processes are highly important in the environment and conventional biotreatment processes. As a branch of biotechnology, biosorption has been aimed at the removal or recovery of organic and inorganic substances from solution by biological material which can include living or dead microorganisms and their components, seaweeds, plant materials, industrial and agricultural wastes and natural residues. For decades biosorption has been heralded as a promising cost-effective clean-up biotechnology. Despite significant progress in our understanding of this complex phenomenon and a dramatic increase in publications in this research area, commercialization of biosorption technologies has been limited so far. This article summarizes existing knowledge on various aspects of the fundamentals and applications of biosorption and critically reviews the obstacles to commercial success and future perspectives.
Biosorption may be simply defined as the removal of substances from solution by biological material. Such substances can be organic and inorganic, and in gaseous, soluble or insoluble forms. ...Biosorption is a physico-chemical process and includes such mechanisms as absorption, adsorption, ion exchange, surface complexation and precipitation. Biosorption is a property of both living and dead organisms (and their components) and has been heralded as a promising biotechnology for pollutant removal from solution, and/or pollutant recovery, for a number of years, because of its efficiency, simplicity, analogous operation to conventional ion exchange technology, and availability of biomass. Most biosorption studies have carried out on microbial systems, chiefly bacteria, microalgae and fungi, and with toxic metals and radionuclides, including actinides like uranium and thorium. However, practically all biological material has an affinity for metal species and a considerable amount of other research exists with macroalgae (seaweeds) as well as plant and animal biomass, waste organic sludges, and many other wastes or derived bio-products. While most biosorption research concerns metals and related substances, including radionuclides, the term is now applied to particulates and all manner of organic substances as well. However, despite continuing dramatic increases in published research on biosorption, there has been little or no exploitation in an industrial context. This article critically reviews aspects of biosorption research regarding the benefits, disadvantages, and future potential of biosorption as an industrial process, the rationale, scope and scientific value of biosorption research, and the significance of biosorption in other waste treatment processes and in the environment. Copyright
Oxalate is a key metabolite that plays a significant role in many metal and mineral transformations mediated by fungi. Metal and mineral transformations are central to geomycological processes ...including nutrient and element cycling, rock, mineral and metal transformations, bioweathering and mycogenic biomineral formation. Some fungal transformations have potential applications in environmental biotechnology, e.g. metal and radionuclide leaching, biorecovery, detoxification and bioremediation, and in the production or deposition of biominerals or metallic elements with catalytic or other properties. Metal and mineral transformations may also result in adverse effects when these processes result in biodeterioration of natural and synthetic materials, rock and mineral-based building materials (e.g. concrete), biocorrosion of metals, alloys and related substances, and adverse effects on radionuclide speciation, mobility and containment. Oxalate is ubiquitous in all these contexts. This paper seeks to draw together salient information from environmental and applied research to emphasize the importance of oxalate in geomycology, biodeterioration, environmental biotechnology and bioremediation.
Lead (Pb) is a serious environmental pollutant in all its chemical forms 1. Attempts have been made to immobilize lead in soil as the mineral pyromorphite using phosphate amendments (e.g., rock ...phosphate, phosphoric acid, and apatite 2–5), although our work has demonstrated that soil fungi are able to transform pyromorphite into lead oxalate 6, 7. Lead metal, an important structural and industrial material, is subject to weathering, and soil contamination also occurs through hunting and shooting 8, 9. Although fungi are increasingly appreciated as geologic agents 10–12, there is a distinct lack of knowledge about their involvement in lead geochemistry. We examined the influence of fungal activity on lead metal and discovered that metallic lead can be transformed into chloropyromorphite, the most stable lead mineral that exists. This is of geochemical significance, not only regarding lead fate and cycling in the environment but also in relation to the phosphate cycle and linked with microbial transformations of inorganic and organic phosphorus. This paper provides the first report of mycogenic chloropyromorphite formation from metallic lead and highlights the significance of this phenomenon as a biotic component of lead biogeochemistry, with additional consequences for microbial survival in lead-contaminated environments and bioremedial treatments for Pb-contaminated land.
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► First discovery of fungal transformation of lead metal into chloropyromorphite ► Highlights a fundamental role of fungi in lead and phosphorus biogeochemistry ► Findings are relevant to bioremedial treatment of Pb-contaminated sites
Electrical energy storage systems such as rechargeable lithium-ion batteries (LiBs) and supercapacitors have shown great promise as sustainable energy storage systems 1–4. However, LiBs have high ...specific energy density (energy stored per unit mass) and act as slow, steady suppliers for large energy demands. In contrast, supercapacitors possess high specific power (energy transferred per unit mass per unit time) and can charge and discharge quickly for low energy demands. In LiBs, graphite is the most common anode material, although high electrolyte sensitivity and low charge capacity can limit performance. Efforts have been made to improve LiB or supercapacitor performance using alternative electrode materials such as carbon nanotubes and manganese oxides (MnxOy) 3, 5–14. Microorganisms play significant roles in metal and mineral biotransformations 15–22. Fungi possess various biomineralization properties, as well as a filamentous mycelium, which may provide mechanical support for mineral deposition. Although some research has been carried out on the application of biological materials as carbon precursors 8, 9, 23, biomineralizing fungal systems have not been investigated. In this research, novel electrochemical materials have been synthesized using a fungal Mn biomineralization process based on urease-mediated Mn carbonate bioprecipitation 24. The carbonized fungal biomass-mineral composite (MycMnOx/C) showed a high specific capacitance (>350 F g−1) in a supercapacitor and excellent cycling stability (>90% capacity was retained after 200 cycles) in LiBs. This is the first demonstration of the synthesis of electrode materials using a fungal biomineralization process, thus providing a novel strategy for the preparation of sustainable electrochemical materials.
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•First synthesis of electrochemical materials from fungal Mn biomineralization is shown•MycMnOx/C showed a high specific capacitance (>350 F g−1) in a supercapacitor•MycMnOx/C exhibited excellent electrochemical performance in a lithium-ion battery•MycMnOx/C shows significant potential for biotechnological development
Li et al. synthesized novel electrochemical materials using a fungal Mn biomineralization process. They studied the electrochemical properties of the carbonized fungal biomass-mineral composite in a supercapacitor and a lithium-ion battery, thus providing a novel biotechnological method for preparation of sustainable electrochemical materials.
Fungal biomineralization Gadd, Geoffrey Michael
Current biology,
12/2021, Letnik:
31, Številka:
24
Journal Article
Recenzirano
Odprti dostop
Fungi are key organisms of the biosphere with major roles in organic-matter decomposition, element cycling, plant pathogenicity, and symbioses in aquatic and terrestrial habitats. The vast majority ...exhibit a filamentous, branching growth form and are aerobic chemoorganotrophs that derive carbon and energy from organic substances, and are particularly associated with soil, the plant-root zone, and rock surfaces. It is now known that some fungi are lithotrophs, deriving energy from the oxidation of inorganic materials, whereas others are photoheterotrophs, deriving additional energy from light for organic matter utilization when oxygen is limited. This means that fungi are of much wider environmental significance than previously thought and explains their ubiquity in locations previously thought to be inimical to fungal existence, such as the deep subsurface and other anaerobic locations. In addition to such free-living species, fungi associated with photosynthetic partners are also of profound biosphere importance. For example, lichens, which are composed of a symbiotic association between a fungus and a phototrophic alga and/or cyanobacterium, are pioneer colonizers and bioweathering agents of rocks and minerals. Mycorrhizas are symbiotic, plant-root-associated fungi found to colonize the majority of plant genera, where they improve plant nutrition through solubilization of essential metals and phosphate from soil minerals. Biomineralization in the soil can also immobilize toxic metals in the vicinity of plant roots, thereby benefiting plant colonization and facilitating revegetation of contaminated habitats. Wherever fungi are found, transformation of metals and minerals is a key aspect of their activity, with biomineralization an important feature. Fungal biomineralization is an important facet of geomycology - namely the roles of fungi in geochemical and geophysical processes. This article seeks to highlight the concept of biomineralization as applied to fungi, the occurrence and significance of important fungal biominerals in natural and synthetic environments, and the applied potential of fungal biomineralization in nanobiotechnology.
Geomicrobiology addresses the roles of microorganisms in geological and geochemical processes, and geomycology is a part of this topic focusing on the fungi. Geoactive roles of fungi include organic ...and inorganic transformations important in nutrient and element cycling, rock and mineral bioweathering, mycogenic biomineral formation, and metal-fungal interactions. Lichens and mycorrhizas are significant geoactive agents. Organic matter decomposition is important for cycling of major biomass-associated elements, e.g., C, H, N, O, P, and S, as well as all other elements found in lower concentrations. Transformations of metals and minerals are central to geomicrobiology, and fungi affect changes in metal speciation, as well as mediate mineral formation or dissolution. Such mechanisms are components of biogeochemical cycles for metals as well as associated elements in biomass, soil, rocks, and minerals, e.g., S, P, and metalloids. Fungi may have the greatest geochemical influence within the terrestrial environment. However, they are also important in the aquatic environment and are significant components of the deep subsurface, extreme environments, and habitats polluted by xenobiotics, metals, and radionuclides. Applications of geomycology include metal and radionuclide bioleaching, biorecovery, detoxification, bioremediation, and the production of biominerals or metal(loid) elements with catalytic or other properties. Adverse effects include biodeterioration of natural and synthetic materials, rock and mineral-based building materials (e.g., concrete), cultural heritage, metals, alloys, and related substances and adverse effects on radionuclide mobility and containment. The ubiquity and importance of fungi in the biosphere underline the importance of geomycology as a conceptual framework encompassing the environmental activities of fungi.
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•Higher alkaline phosphatase activity was found for sediments rather than soils.•Community similarity decayed against higher geographical distance.•Different landscapes of ...phoD-harboring bacteria between soils and sediments.•Electrical conductivity shaping taxonomic and phylogenetic α-diversities.•Ecological processes drive biogeography of phoD-harboring bacteria.
Deciphering biogeographical patterns of alkaline phosphatase (phoD)-harboring bacteria is essential to understand organic phosphorus mineralization. However, it is poorly understood about distribution pattern and diversity maintenance mechanisms of phoD-harboring bacteria (PHB) in watershed ecosystems. Here, we estimated ecological processes shaping landscape of PHB in soils and sediments along the Yangtze River. The PHB community similarity decayed against higher geographical distance at taxonomic and phylogenetic levels, and larger compositional variation in PHB community were found in sediments only. The PHB displayed higher α-diversities, broader environmental breadths, higher community stability, and stronger species replacement in soils. Conversely, PHB showed stronger phylogenetic signals in sediments. Stochastic and differentiating processes dominated community assemblies of PHB in both soils and sediments. Electrical conductivity displayed decisive roles in shaping PHB diversity for soils and sediments at taxonomic and phylogenetic levels. Our results emphasized differences in distribution patterns of PHB between soils and sediments, and highlighted ecological processes shaping landscapes of PHB in soils and sediments along the Yangtze River. The phosphorus cycling-related findings might be helpful to estimate ecological potential of a watershed ecosystem and could provide new insights for ecological protection policy for the Yangtze River.
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•Bioleaching is good at deep As removal from regenerated product of spent SCR catalyst.•Bioleaching results in a maximum As removal of 53.1% at a high pulp density of ...10%.•Corresponding As residue of 174 mg/kg below limiting value of 200 mg/kg is attained.•Strong activation of regenerated product occurs by bioleaching along with As removal.•Cells secrete an amount of cysteine accounting for As removal and product activation.
Selective catalytic reaction (SCR) is widely used in flue gas denitrification to convert NOx air pollutants into N2 and H2O in the presence of SCR catalyst, but arsenic poisoning causes serious deactivation of SCR catalyst and produces a huge amount of spent SCR catalyst worldwide. Therefore, the regeneration and recycling of spent SCR catalysts are of great necessity for the sustainable flue gas denitrification due to the very high cost of replacing commercial catalysts. Nowadays, a combination of alkali treatment and acid washing is usually used to regenerate spent SCR catalysts. However, high residue of As strongly inhibits the catalytic activity of the regenerated products. In this study, an active bioleaching liquor produced by Acidithiobacillus thiooxidans as indirect bioleaching was attempted to deeply remove As from the regenerated product for the first time. The results showed that bioleaching resulted in maximal As removal of 53.1% even at a high pulp density of 10% to harvest a minimum As residue of 174 mg/kg below the limiting value of 200 mg/kg; whereas H2SO4 leaching attained 6.7% As removal and as high as 345 mg/kg of As residue. A stronger activation of the regenerated products simultaneously occurred with the bioleaching. A great amount of cysteine in the bioleaching liquor secreted by the microbe accounts for both the enhancement of As removal and strong activation of the product. A novel mechanism is proposed to explain the excellent As removal by the indirect bioleaching based on nucleophilic attack of the sulfhydryl groups in cysteine.
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