Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    European journal of soil science 48 (1997), S. 0 
    ISSN: 1365-2389
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Humic acids from six Brazilian topsoils (three Latosols and three Podzols) and five soil fungal melanins were hydrolysed and the released amino sugars qualitatively and quantitatively determined by capillary gas-liquid chromatography. Melanins were obtained from liquid culture media, synthesized with nitrate or asparagine as a source of N, of Stachybotrys atra, Aspergillus glaucus, Eurotium echinulatum and Hendersonula toruloidea. Glucosamine (48–60%), galactosamine (39–52%), and traces of mannosamine were detected in all humic acids. The total amino sugar content ranged from 1351 to 2287 mg kg−1. In the fungal melanins analysed, mostly glucosamine (80–99%) and trace to small amounts of galactosamine and mannosamine (〈10%) were found in amounts ranging from 192 to 635 mg kg−1. The Occurrence of mannosamine in fungal melanins and fungal polysaccharides had not previously been found. The present study gives additional data to the theory that fungal melanins may play a role, as precursors, in the formation of soil organic matter.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1432-0789
    Schlagwort(e): Key words Copper porphyrin ; Actinomycete melanins ; Electron paramagnetic resonance spectroscopy ; Brazilian soils
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The coordination chemistry of iron (III) (Fe3+) and copper (II) (Cu2+) in melanins synthesized by seven actinomycetes isolated from Brazilian latosol soils under savanna (cerrado) vegetation was investigated using electron paramagnetic resonance (EPR) and ultraviolet-visible (UV-Vis) spectroscopy. The EPR spectra indicated the presence of Cu2+ ions bound to oxygenated and nitrogenous functional groups, and rhombic coordinated Fe3+ ions. In some of the actinomycete melanins the EPR hyperfine splitting of Cu+2 ion complexes was well resolved, and indicated four magnetically equivalent nitrogen atoms in a plane. This result suggested the presence of Cu+2 porphyrin complexes, which was confirmed by Soret bands in the 400-nm region of the UV-Vis spectra. The concentration of Mn in actinomycete melanins, determined by inductively coupled plasma atomic emission spectroscopy, was lower than those of Cu and Fe.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    ISSN: 1432-0789
    Schlagwort(e): Actinomycetes ; Melanins ; Infrared analysis ; Soil humic acids ; Tropical soil ; Aromatic central core
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Eleven actinomycete melanins were characterized by elemental and functional group and infrared analysis. A soil humic acid from a Brazilian topsoil, a darkred latosol under savanna grassland, analysed previously, was used for comparative purposes. C, N, total acidity, COOH, and phenolic OH contents were within the ranges reported for soil humic acids and fungal melanins. Compared to the soil humic acid, the actinomycete melanins showed greater detail, indicative of higher aliphaticity. Most of these were, in varying degrees, similar to the type III IR spectra of humic acids, which are characteristically high in proteinaceous material, and with variable amounts of polysaccharides. The exceptions were two melanin spectra that showed more resemblance to the humic acid from the dark-red latosol, which belongs to the type I spectra of soil humic acids, a category that includes most soil humic acids. The probable participation of melanic actinomycetes in the formation of humic polymers in discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...