Fungal Mobilization of Selenium in the Presence of Hausmannite and Ferric Oxyhydroxides

Bioleaching of mineral phases plays a crucial role in the mobility and availability of various elements, including selenium. Therefore, the leachability of selenium associated with the surfaces of ferric and manganese oxides and oxyhydroxides, the prevailing components of natural geochemical barriers, has been studied in the presence of filamentous fungus. Both geoactive phases were exposed to selenate and subsequently to growing fungus Aspergillus niger for three weeks. This common soil fungus has shown exceptional ability to alter the distribution and mobility of selenium in the presence of both solid phases. The fungus initiated the extensive bioextraction of selenium from the surfaces of amorphous ferric oxyhydroxides, while the hausmannite (Mn3O4) was highly susceptible to biodeterioration in the presence of selenium. This resulted in specific outcomes regarding the selenium, iron, and manganese uptake by fungus and residual selenium concentrations in mineral phases as well. The adverse effects of bioleaching on fungal growth are also discussed.

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Basic interactions of Aspergillus niger with Se(IV)

Nova Biotechnologica et Chimica ◽

10.36547/nbc.1219 ◽

2021 ◽

Vol 9 (2) ◽

pp. 141-145

Author(s):

Martin Urík ◽

Jaroslav Ševc ◽

Pavol Littera ◽

Marek Kolenčík ◽

Slavomír Čerňanský

Keyword(s):

Aspergillus Niger ◽

Liquid Medium ◽

Filamentous Fungus ◽

Indoor Environment ◽

Fungal Growth ◽

Fungal Strain ◽

Aerobic Conditions ◽

Negligible Amount ◽

Total Selenium ◽

Toxicity Effects

Filamentous fungus Aspergillus niger is commonly found on decaying vegetation or in indoor environment and has a number of uses, including application in bioremediation. Hence, the basic interactions of this common mould with selenite were studied, including biovolatilization, bioaccumulation and toxicity effects of selenite on fungal growth. The fungal strain, originally isolated from noncontaminated soil, was cultivated under aerobic conditions on liquid cultivation media with concentration of Se(IV) 19 or 27 mg.l-1 during 25 days. The fungal growth in the presence of selenite was not inhibited when compared to control, only the sporulation was reduced. The concentration of Se(IV) in liquid medium decreased rapidly within first ten days to 1 mg.l-1. However, according to results from the 25th day of cultivation, the concentration of total selenium in medium did not change significantly and only negligible amount of selenium (less then 1%) was bioaccumulated. That indicates some biotransformation of selenite into other selenium species. During the cultivation, up to 21% of total amount of selenium was transformed into volatile derivatives (biovolatilization) by filamentous fungus A. niger.

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Bioleaching of Manganese Oxides at Different Oxidation States by Filamentous Fungus Aspergillus niger

Journal of Fungi ◽

10.3390/jof7100808 ◽

2021 ◽

Vol 7 (10) ◽

pp. 808

Author(s):

Bence Farkas ◽

Marek Bujdoš ◽

Filip Polák ◽

Michaela Matulová ◽

Martin Cesnek ◽

...

Keyword(s):

Aspergillus Niger ◽

Filamentous Fungus ◽

Manganese Oxides ◽

Culture Medium ◽

Soil Fungi ◽

Alternative Pathway ◽

Manganese Content ◽

Oxidation States ◽

Reductive Dissolution ◽

The Stability

This work aimed to examine the bioleaching of manganese oxides at various oxidation states (MnO, MnO·Mn2O3, Mn2O3 and MnO2) by a strain of the filamentous fungus Aspergillus niger, a frequent soil representative. Our results showed that the fungus effectively disintegrated the crystal structure of selected mineral manganese phases. Thereby, during a 31-day static incubation of oxides in the presence of fungus, manganese was bioextracted into the culture medium and, in some cases, transformed into a new biogenic mineral. The latter resulted from the precipitation of extracted manganese with biogenic oxalate. The Mn(II,III)-oxide was the most susceptible to fungal biodeterioration, and up to 26% of the manganese content in oxide was extracted by the fungus into the medium. The detected variabilities in biogenic oxalate and gluconate accumulation in the medium are also discussed regarding the fungal sensitivity to manganese. These suggest an alternative pathway of manganese oxides’ biodeterioration via a reductive dissolution. There, the oxalate metabolites are consumed as the reductive agents. Our results highlight the significance of fungal activity in manganese mobilization and transformation. The soil fungi should be considered an important geoactive agent that affects the stability of natural geochemical barriers.

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Fungus Aspergillus niger Processes Exogenous Zinc Nanoparticles into a Biogenic Oxalate Mineral

Journal of Fungi ◽

10.3390/jof6040210 ◽

2020 ◽

Vol 6 (4) ◽

pp. 210

Author(s):

Martin Šebesta ◽

Martin Urík ◽

Marek Bujdoš ◽

Marek Kolenčík ◽

Ivo Vávra ◽

...

Keyword(s):

Aspergillus Niger ◽

Test Organism ◽

Fungal Growth ◽

Soil Fungus ◽

Industrial Applications ◽

Zno Nps ◽

Zinc Nanoparticles ◽

Extracellular Metabolites ◽

Zn Bioavailability ◽

The Stability

Zinc oxide nanoparticles (ZnO NPs) belong to the most widely used nanoparticles in both commercial products and industrial applications. Hence, they are frequently released into the environment. Soil fungi can affect the mobilization of zinc from ZnO NPs in soils, and thus they can heavily influence the mobility and bioavailability of zinc there. Therefore, ubiquitous soil fungus Aspergillus niger was selected as a test organism to evaluate the fungal interaction with ZnO NPs. As anticipated, the A. niger strain significantly affected the stability of particulate forms of ZnO due to the acidification of its environment. The influence of ZnO NPs on fungus was compared to the aqueous Zn cations and to bulk ZnO as well. Bulk ZnO had the least effect on fungal growth, while the response of A. niger to ZnO NPs was comparable with ionic zinc. Our results have shown that soil fungus can efficiently bioaccumulate Zn that was bioextracted from ZnO. Furthermore, it influences Zn bioavailability to plants by ZnO NPs transformation to stable biogenic minerals. Hence, a newly formed biogenic mineral phase of zinc oxalate was identified after the experiment with A. niger strain’s extracellular metabolites highlighting the fungal significance in zinc biogeochemistry.

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A cotyledonary agglutinin from Luetzelburgia auriculata inhibits the fungal growth of Colletotrichum lindemuthianum, Fusarium solani and Aspergillus niger and impairs glucose-stimulated acidification of the incubation medium by Saccharomyces cerevisiae cells

Plant Science ◽

10.1016/j.plantsci.2005.05.010 ◽

2005 ◽

Vol 169 (3) ◽

pp. 629-639 ◽

Cited By ~ 8

Author(s):

Vânia M.M. Melo ◽

Ilka M. Vasconcelos ◽

Valdirene M. Gomes ◽

Maura Da Cunha ◽

Arlete A. Soares ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Aspergillus Niger ◽

Fusarium Solani ◽

Incubation Medium ◽

Fungal Growth ◽

Colletotrichum Lindemuthianum

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Ultrasound-Assisted Citric Acid Extraction of Zinc in Plateau Red Soil and Tessier Speciation Study

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.4464 ◽

2013 ◽

Vol 726-731 ◽

pp. 4464-4467

Author(s):

Wei Wei ◽

Xue Jin Zhou ◽

Yun Tao Gao

Keyword(s):

Heavy Metal ◽

Citric Acid ◽

Manganese Oxides ◽

Red Soil ◽

Extraction Rate ◽

Acid Extraction ◽

Speciation Study ◽

Ultrasonic Assisted ◽

Ultrasound Assisted ◽

Iron And Manganese

Taking plateau red soil as research object, using the ultrasonic-assisted organic acid extraction the heavy metal zinc in it, and analyze the form of zinc. Results showed that the extraction rate can reach 68%, with the increase of time, the extraction effect of zinc is obviously enhanced in this method. Ultrasonic-assisted citric acid extraction soil can increase the extraction rate of exchangeable, bound to carbonates and bound to iron and manganese oxides relatively.

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Lysis and biological control of Aspergillus niger by Bacillus subtilis AF 1

Canadian Journal of Microbiology ◽

10.1139/m96-072 ◽

1996 ◽

Vol 42 (6) ◽

pp. 533-538 ◽

Cited By ~ 64

Author(s):

A. R. Podile ◽

A. P. Prakash

Keyword(s):

Biological Control ◽

Bacillus Subtilis ◽

Aspergillus Niger ◽

Fungal Growth ◽

Dry Weight ◽

Crown Rot ◽

Fungal Mycelium ◽

Infested Soil ◽

Dual Culture ◽

Bacterial Cells

A biocontrol rhizobacterial strain of Bacillus subtilis AF 1 grown for 6 h was coinoculated with Aspergillus niger at different time intervals and microscopic observations revealed adherence of bacterial cells to the fungal mycelium. Bacterial cells multiplied in situ and colonized the mycelial surface. Growth of AF 1 resulted in damage to the cell wall, followed by lysis. AF 1 inoculation into media containing A. niger at 0, 6, and 12 h suppressed >90% fungal growth, while in 18- and 24-h cultures fungal growth inhibition was 70 and 56%, respectively, in terms of dry weight. In dual culture the fungal growth was not accompanied by formation of spores. The mycelial preparation of A. niger as principal carbon source supported the growth of B. subtilis, as much as chitin. Extracellular protein precipitate from B. subtilis culture filtrate had a significant growth-retarding effect on A. niger. Groundnut seeds bacterized with B. subtilis showed a reduced incidence of crown rot in A. niger infested soil, suggesting a possible role of B. subtilis in biological control of A. niger.Key words: mycolytic bacteria, Bacillus subtilis, Aspergillus niger, biological control.

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Strategies for EELS Data Analysis. Introducing UMAP and HDBSCAN for Dimensionality Reduction and Clustering

Microscopy and Microanalysis ◽

10.1017/s1431927621013696 ◽

2021 ◽

pp. 1-14

Author(s):

Javier Blanco-Portals ◽

Francesca Peiró ◽

Sònia Estradé

Keyword(s):

Dimensionality Reduction ◽

Clustering Analysis ◽

Manganese Oxides ◽

Spatial Clustering ◽

State Of The Art ◽

Core Loss ◽

Nonnegative Matrix ◽

Case Scenario ◽

Electron Energy Loss ◽

Iron And Manganese

Hierarchical density-based spatial clustering of applications with noise (HDBSCAN) and uniform manifold approximation and projection (UMAP), two new state-of-the-art algorithms for clustering analysis, and dimensionality reduction, respectively, are proposed for the segmentation of core-loss electron energy loss spectroscopy (EELS) spectrum images. The performances of UMAP and HDBSCAN are systematically compared to the other clustering analysis approaches used in EELS in the literature using a known synthetic dataset. Better results are found for these new approaches. Furthermore, UMAP and HDBSCAN are showcased in a real experimental dataset from a core–shell nanoparticle of iron and manganese oxides, as well as the triple combination nonnegative matrix factorization–UMAP–HDBSCAN. The results obtained indicate how the complementary use of different combinations may be beneficial in a real-case scenario to attain a complete picture, as different algorithms highlight different aspects of the dataset studied.

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