Potential Bioleaching Effects in In Situ Recovery Applications

2017 ◽  
Vol 262 ◽  
pp. 456-460 ◽  
Author(s):  
Constanze Richter ◽  
Harald Kalka ◽  
Horst Märten
Keyword(s):  
Reactive Transport ◽  
Potential Role ◽  
Oxidation Potential ◽  
Ex Situ ◽  
Metal Dissolution ◽  
Practical Applications ◽  
Kinetic Rates ◽  
Indirect Catalysis

The potential role of microorganisms in the in-situ recovery (ISR) of technology metals, in particular from reduced ores, is not well understood, but attracts increasing interest worldwide. Based on the feasibility criteria for ISR applications in general, effects of biota on kinetic rates of leaching are systematized. The indirect catalysis of leaching by microbial (re-)oxidation of Fe2+ to Fe3+ as directly acting e- acceptor is a well verified mechanism, however, for practical applications this requires the availability of an oxidant in the leachant. The ex-situ bio-oxidation of Fe in an aerated bioreactor is considered as an alternative. Reactive transport simulations of ISR from sulfidic Cu ores based on kinetic rates as function of pH and oxidation potential (concentration of e- acceptors) in comparison with thermodynamically driven metal dissolution (constrained by oxidation potential) demonstrate the key parameters for (bio-)leaching productivity.

scholarly journals The Sapotaceae of Indonesia and the Potential Role of Botanic Gardens in their Conservation

2018 ◽  
pp. 141-154
Author(s):  
Prima W.K. Hutabarat ◽  
Peter Wilkie
Keyword(s):  
Native Species ◽  
Potential Role ◽  
Threat Assessment ◽  
Ex Situ ◽  
Botanic Gardens ◽  
Global Threat ◽  
Major Impediment

Indonesia holds a large percentage of Malesian Sapotaceae taxa with an estimated 15 genera and 158 species. Bogor Botanic Gardens currently hold 12 genera and 41 species of which 29 are native to Indonesia. This represents just under 20% of Sapotaceae species currently recorded from Indonesia. The utility of these collections is dependent on the type of data associated with them and on the quality of identification of the material. Of the 29 native species only three have had a global threat assessment made and, of these, one, Madhuca boerlageana (Burck) Baehni, is considered Critically Endangered. The regional botanic gardens initiative of the Indonesian government is establishing botanic gardens in each of the 47 ecoregions of Indonesia. This new initiative is potentially very important for in situ and ex situ conservation of the Indonesian flora. So far it has brought into cultivation 39 threatened species, however none of these are Sapotaceae. The lack of global IUCN threat data is a major impediment to the prioritisation of collection, cultivation and conservation of Sapotaceae species.

Insights into the Role of In-situ and Ex-situ Hydrogen Peroxide for Enhanced Ferrate(VI) Towards Oxidation of Organic Contaminants

2021 ◽  
pp. 117548
Author(s):  
Mengfan Luo ◽  
Hongyu Zhou ◽  
Peng Zhou ◽  
Leiduo Lai ◽  
Wen Liu ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Contaminants ◽  
Ex Situ

scholarly journals Interactions of U2 Gene Loci and Their Nuclear Transcripts with Cajal (Coiled) Bodies: Evidence for PreU2 within Cajal Bodies

2000 ◽  
Vol 11 (9) ◽  
pp. 2987-2998 ◽  
Author(s):  
Kelly P. Smith ◽  
Jeanne Bentley Lawrence
Keyword(s):  
Potential Role ◽  
Coiled Body ◽  
Oligonucleotide Probes ◽  
Primary Transcript ◽  
U2 Snrna ◽  
Rna Foci ◽  
Coiled Bodies ◽  
Snrna Gene

The Cajal (coiled) body (CB) is a structure enriched in proteins involved in mRNA, rRNA, and snRNA metabolism. CBs have been shown to interact with specific histone and snRNA gene loci. To examine the potential role of CBs in U2 snRNA metabolism, we used a variety of genomic and oligonucleotide probes to visualize in situ newly synthesized U2 snRNA relative to U2 loci and CBs. Results demonstrate that long spacer sequences between U2 coding repeats are transcribed, supporting other recent evidence that U2 transcription proceeds past the 3′ box. The presence of bright foci of this U2 locus RNA differed between alleles within the same nucleus; however, this did not correlate with the loci's association with a CB. Experiments with specific oligonucleotide probes revealed signal for preU2 RNA within CBs. PreU2 was also detected in the locus-associated RNA foci, whereas sequences 3′ of preU2 were found only in these foci, not in CBs. This suggests that a longer primary transcript is processed before entry into CBs. Although this work shows that direct contact of a U2 locus with a CB is not simply correlated with RNA at that locus, it provides the first evidence of new preU2 transcripts within CBs. We also show that, in contrast to CBs, SMN gems do not associate with U2 gene loci and do not contain preU2. Because other evidence indicates that preU2 is processed in the cytoplasm before assembly into snRNPs, results point to an involvement of CBs in modification or transport of preU2 RNA.

scholarly journals The Role of Gardens in Integrated Conservation Practice

2019 ◽  
pp. 177-188
Author(s):  
Audrey Denvir ◽  
Jeannine Cavender-Bares ◽  
Antonio González-Rodríguez
Keyword(s):  
Plant Conservation ◽  
Ex Situ ◽  
Conservation Practice ◽  
Integrated Research ◽  
Academic Researchers ◽  
Conservation Plan ◽  
Species Specific ◽  
Integrated Conservation

Gardens and horticulturists play an increasingly important role in plant conservation, both in situ and ex situ. Integrated research and conservation of species intends to work across fields to connect science to conservation practice by engaging actors from different sectors, including gardens. The case of integrated conservation of Quercus brandegeei, a microendemic oak species in Baja California Sur, Mexico, is presented as an example of a collaboration between gardens and academic researchers to create a species-specific conservation plan that incorporates horticultural knowledge.

The Role of Zoos in Tree Kangaroo Conservation: Connecting Ex Situ and In Situ Conservation Action

2021 ◽  
pp. 329-361
Author(s):  
Karin R. Schwartz ◽  
Onnie Byers ◽  
Philip Miller ◽  
Jacque Blessington ◽  
Brett Smith
Keyword(s):  
In Situ Conservation ◽  
Ex Situ ◽  
Conservation Action

In situ Mineralization of Hydroxyapatite for a Molecular Control of Mechanical Responses in Hydroxyapatite-Polymer Composites for Bone Replacement

2001 ◽  
Vol 711 ◽  
Author(s):  
Kalpana Katti ◽  
Praveen Gujjula ◽  
Arunprakash Ayyarsamy ◽  
Timothy Arens
Keyword(s):  
Polymer Composites ◽  
Polyacrylic Acid ◽  
Mechanical Response ◽  
Ex Situ ◽  
Molecular Control ◽  
Mechanical Responses ◽  
Initial Stage ◽  
Ir Spectroscopic

ABSTRACTIn situ mineralization of hydroxyapatite (HAP) and the role of organics in initial nucleation and growth of HAP is critical for the resulting nano and microstructure of HAP. In situ mineralization of hydroxyapatite (HAP) in the presence of Ca binding polymers such as polyacrylic acid has shown some promise towards improvement of mechanical response of uniaxial compressed HAP/polymer composites to loading. This work represents fundamental studies on the nature of in situ HAP precipitation on resulting microstructure of the composite and bulk mechanical properties. Specifically, an experimental study, evaluating the role of initial stage mineralization of HAP on bulk mechanical responses is conducted. Fourier transform infrared (FT-IR) spectroscopic (with micro attenuated total reflectance) techniques are utilized to evaluate the association of polymer (polyacrylic acid) with HAP during mineralization of HAP. In situ HAP exhibits a faster mineralization as compared to the ex situ mineralization samples, This improved kinetics is responsible for altering the resulting micro and nanostructure of the HAP/polymer composite. Small spectral changes are detected in the absorbance spectra of in situ HAP as compared to ex situ samples. Changes in mechanical response to loading included improvement in strain-to-failure and resulting toughness characteristics of the in situ composite. The control and development of molecular-level associations of polymer with HAP is suggested to be critical for the resulting macro properties. Our results may have significant implications for design of nanocomposites for biomedical applications.

scholarly journals Overview on the Role of Advance Genomics in Conservation Biology of Endangered Species

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Suliman Khan ◽  
Ghulam Nabi ◽  
Muhammad Wajid Ullah ◽  
Muhammad Yousaf ◽  
Sehrish Manan ◽  
...  
Keyword(s):  
Animal Species ◽  
Anthropogenic Activities ◽  
Ex Situ ◽  
Endangered Plants ◽  
Monitoring Tools ◽  
Sixth Mass Extinction ◽  
Novice Readers ◽  
Hybridization And Introgression

In the recent era, due to tremendous advancement in industrialization, pollution and other anthropogenic activities have created a serious scenario for biota survival. It has been reported that present biota is entering a “sixth” mass extinction, because of chronic exposure to anthropogenic activities. Variousex situandin situmeasures have been adopted for conservation of threatened and endangered plants and animal species; however, these have been limited due to various discrepancies associated with them. Current advancement in molecular technologies, especially, genomics, is playing a very crucial role in biodiversity conservation. Advance genomics helps in identifying the segments of genome responsible for adaptation. It can also improve our understanding about microevolution through a better understanding of selection, mutation, assertive matting, and recombination. Advance genomics helps in identifying genes that are essential for fitness and ultimately for developing modern and fast monitoring tools for endangered biodiversity. This review article focuses on the applications of advanced genomics mainly demographic, adaptive genetic variations, inbreeding, hybridization and introgression, and disease susceptibilities, in the conservation of threatened biota. In short, it provides the fundamentals for novice readers and advancement in genomics for the experts working for the conservation of endangered plant and animal species.

scholarly journals Visualizing and isolating iron-reducing microorganisms at single cell level

2020 ◽  
Author(s):  
Cuifen Gan ◽  
Rongrong Wu ◽  
Yeshen Luo ◽  
Jianhua Song ◽  
Dizhou Luo ◽  
...  
Keyword(s):  
Single Cell ◽  
Iron Reduction ◽  
High Sensitivity ◽  
Ex Situ ◽  
Single Cell Level ◽  
Cell Level ◽  
Cell Sorter ◽  
Fluorescent Intensity

AbstractIron-reducing microorganisms (FeRM) play key roles in many natural and engineering processes. Visualizing and isolating FeRM from multispecies samples are essential to understand the in-situ location and geochemical role of FeRM. Here, we visualized FeRM by a “turn-on” Fe2+-specific fluorescent chemodosimeter (FSFC) with high sensitivity, selectivity and stability. This FSFC could selectively identify and locate active FeRM from either pure culture, co-culture of different bacteria or sediment-containing samples. Fluorescent intensity of the FSFC could be used as an indicator of Fe2+ concentration in bacterial cultures. By integrating FSFC with a single cell sorter, we obtained three FSFC-labeled cells from an enriched consortia and all of them were subsequently evidenced to be capable of iron-reduction and two unlabeled cells were evidenced to have no iron-reducing capability, further confirming the feasibility of the FSFC.ImportanceVisualization and isolation of FeRM from samples containing multispecies are commonly needed by researchers from different disciplines, such as environmental microbiology, environmental sciences and geochemistry. However, no available method has been reported. In this study, we provid a solution to visualize FeRM and evaluate their activity even at single cell level. Integrating with single cell sorter, FeRM can also be isolated from samples containing multispecies. This method can be used as a powerful tool to uncover the in-situ or ex-situ role of FeRM and their interactions with ambient microbes or chemicals.

scholarly journals Cryptic role of tetrathionate in the sulfur cycle: A study from Arabian Sea oxygen minimum zone sediments

2019 ◽  
Author(s):  
Subhrangshu Mandal ◽  
Sabyasachi Bhattacharya ◽  
Chayan Roy ◽  
Moidu Jameela Rameez ◽  
Jagannath Sarkar ◽  
...  
Keyword(s):  
Arabian Sea ◽  
Potential Role ◽  
Sediment Cores ◽  
Oxygen Minimum Zone ◽  
Sulfur Cycle ◽  
Metagenome Analysis ◽  
Minimum Zone ◽  
Oxygen Minimum

ABSTRACTTo explore the potential role of tetrathionate in the sulfur cycle of marine sediments, the population ecology of tetrathionate-forming, oxidizing, and respiring microorganisms was revealed at 15-30 cm resolution along two, ∼3-m-long, cores collected from 530- and 580-mbsl water-depths of Arabian Sea, off India’s west coast, within the oxygen minimum zone (OMZ). Metagenome analysis along the two sediment-cores revealed widespread occurrence of the structural genes that govern these metabolisms; high diversity and relative-abundance was also detected for the bacteria known to render these processes. Slurry-incubation of the sediment-samples, pure-culture isolation, and metatranscriptome analysis, corroborated thein situfunctionality of all the three metabolic-types. Geochemical analyses revealed thiosulfate (0-11.1 μM), pyrite (0.05-1.09 wt %), iron (9232-17234 ppm) and manganese (71-172 ppm) along the two sediment-cores. Pyrites (via abiotic reaction with MnO2) and thiosulfate (via oxidation by chemolithotrophic bacteria prevalentin situ) are apparently the main sources of tetrathionate in this ecosystem. Tetrathionate, in turn, can be either converted to sulfate (via oxidation by the chemolithotrophs present) or reduced back to thiosulfate (via respiration by native bacteria); 0-2.01 mM sulfide present in the sediment-cores may also reduce tetrathionate abiotically to thiosulfate and elemental sulfur. Notably tetrathionate was not detectedin situ- high microbiological and geochemical reactivity of this polythionate is apparently instrumental in the cryptic nature of its potential role as a central sulfur cycle intermediate. Biogeochemical roles of this polythionate, albeit revealed here in the context of OMZ sediments, may well extend to the sulfur cycles of other geomicrobiologically-distinct marine sediment horizons.

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