Mutaur There was a problem providing the content you requested Expression of meiotic drive elements Spore killer-2 and Spore killer-3 in asci of Neurospora tetrasperma. No other cookies than the ones mentioned above are used on our websites. Most of their isolates are T. We appreciate many people who sent us cultures through the years. Hypocrea lixii, the teleomorph of Trichoderma harzianum Trichoderma afroharzianumT.
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Therefore, the culture of the fungus was optimized in terms of cell concentration and hyphae qualitative aspect. The biossorption of copper II ions using non-viable biomass of Hypocrea lixii was measured, and sorption isotherms were constructed. For the nanoparticle synthesis, the viable and non-viable biomasses of the fungus were initially used. Transmission electron microscopy TEM analysis demonstrated the formation of nanoparticles of 15nm of mean diameter inside the cells and in the cell wall for the non-viable biomass.
For the viable biomass the particles obtained had 30nm of mean diameter and were located exclusively outside the cells. The use of viable and non-viable biomass suspension extracts was also investigated. The extracts were obtained after contact with double deionized water for 24 hours. Transmission electron microscopy TEM analysis showed the formation of particles with mean diameter of 12nm, for the viable biomass extract, and 10nm for the non-viable biomass extract.
A method of obtaining cell extracts through centrifugation was also evaluated for the synthesis of copper nanoparticles. Transmission electron microscopy TEM analysis confirmed the formation of nanoparticles with mean diameter of 13nm. Energy dispersive X-ray spectroscopy EDS was performed on the particles found in samples of the centrifuged cells extract and they were found to be composed of copper only, endorsing the ability of synthesis for this extract.
In order to define which compounds present in the cell extracts could be involved in the synthesis reaction, mass spectrometry MALDI-TOF and gas chromatography analyses were performed for the different extracts produced.
Through the results of those analyses it was seen that the compounds that interact with the copper II ions are amino acids and sugars. Only for the centrifuged cells extract it was possible to confirm the presence of compounds with molecular weights between 4kDa and 20kDa, compatible with proteins.
Having confirmed the ability of the fungus of synthesizing copper nanoparticles through different methods, a central rotational composite design of experiments was established as a way of assessing the influence of the pH and temperature on the diameter of the particles formed using the centrifuged cells extract.
The diameter of the particles was measured using dynamic light scattering DLS. Moreover, the diameter found for the experiments were considerably larger than the observed through transmission electron microscopy. It was considered that this observation was a result of the presence of ligands that act as stabilizers for the particles and that contribute to a virtual increase of the diameter measured.
These ligands are compounds present in the extract and that are not shown in electron microscopy due to the lack of contrast. Furthermore, the DLS analysis is an indirect measurement of the diameter and other analyses are needed to confirm the results obtained. Through the results found in this work, there was a confirmation of the ability of the fungus Hypocrea lixii to synthesize copper nanoparticles.
Promising methodologies were proposed that might, after further studies, become an industrial process.
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