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- Hammer, Edith, et al.
(författare)
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A mycorrhizal fungus grows on biochar and captures phosphorus from its surfaces
- 2014
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Ingår i: Soil Biology & Biochemistry. - : Elsevier BV. - 0038-0717. ; 77, s. 252-260
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Tidskriftsartikel (refereegranskat)abstract
- Biochar application to soils has potential to simultaneously improve soil fertility and store carbon to aid climate change mitigation. While many studies have shown positive effects on plant yields, much less is known about the synergies between biochar and plant growth promoting microbes, such as mycorrhizal fungi. We present the first evidence that arbuscular mycorrhizal (AM) fungi can use biochar as a physical growth matrix and nutrient source. We used monoxenic cultures of the AM fungus Rhizophagus irregularis in symbiosis with carrot roots. Using scanning electron microscopy we observed that AM fungal hyphae grow on and into two contrasting types of biochar particles, strongly attaching to inner and outer surfaces. Loading a nutrient-poor biochar surface with nutrients stimulated hyphal colonization. We labeled biochar surfaces with P-33 radiotracer and found that hyphal contact to the biochar surfaces permitted uptake of P-33 and its subsequent translocation to the associated host roots. Direct access of fungal hyphae to biochar surfaces resulted in six times more P-33 translocation to the host roots than in systems where a mesh prevented hyphal contact with the biochar. We conclude that AM fungal hyphae access microsites within biochar, that are too small for most plant roots to enter (<10 mu m), and can hence mediate plant phosphorus uptake from the biochar. Thus, combined management of biochar and AM fungi could contribute to sustainable soil and climate management by providing both a carbon-stable nutrient reservoir and a symbiont that facilitates nutrient uptake from it. (C) 2014 Elsevier Ltd. All rights reserved.
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| 2. |
- Okhrimenko, Denis V., et al.
(författare)
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Hydrolytic Stability of 3-Aminopropylsilane Coupling Agent on Silica and Silicate Surfaces at Elevated Temperatures
- 2017
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 9:9, s. 8344-8353
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Tidskriftsartikel (refereegranskat)abstract
- 3-Aminopropylsilane (APS) coupling agent is widely used in industrial, biomaterial, and medical applications to improve adhesion of polymers to inorganic materials. However, during exposure to elevated humidity and temperature, the deposited APS layers can decompose, leading to reduction in coupling efficiency, thus decreasing the product quality and the mechanical strength of the polymer–inorganic material interface. Therefore, a better understanding of the chemical state and stability of APS on inorganic surfaces is needed. In this work, we investigated APS adhesion on silica wafers and compared its properties with those on complex silicate surfaces such as those used by industry (mineral fibers and fiber melt wafers). The APS was deposited from aqueous and organic (toluene) solutions and studied with surface sensitive techniques, including X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), streaming potential, contact angle, and spectroscopic ellipsometry. APS configuration on a model silica surface at a range of coverages was simulated using density functional theory (DFT). We also studied the stability of adsorbed APS during aging at high humidity and elevated temperature. Our results demonstrated that APS layer formation depends on the choice of solvent and substrate used for deposition. On silica surfaces in toluene, APS formed unstable multilayers, while from aqueous solutions, thinner and more stable APS layers were produced. The chemical composition and substrate roughness influence the amount of deposited APS. More APS was deposited and its layers were more stable on fiber melt than on silica wafers. The changes in the amount of adsorbed APS can be successfully monitored by streaming potential. These results will aid in improving industrial- and laboratory-scale APS deposition methods and increasing adhesion and stability, thus increasing the quality and effectiveness of materials where APS is used as a coupling agent.
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