Banca de DEFESA: JEFERSON DO ROSARIO ALMEIDA

The integration of Nanomaterials in the Cell Wall of Filamentous Fungi for the production of biohybrid and biomimetic materials.

Titanium oxide, filamentous fungi, MOFs, biohybrid materials, biomorphic materials, titanate nanotubes

The present work aims to integrate nanomaterials to the cell wall of filament fungi, aiming the production of luminescent biohybrid materials and semiconductor biomorphic materials. In order to obtain luminescent biohybrid materials, fungi of the species Aspergillus niger, Phialomyces macrosporus and Trichoderma spp were grown in a medium containing luminescent lanthanide metal-organic framework (Tb-MOFs and Eu-MOFs). The biohybrid was characterized by scanning electron microscopy (SEM), fluorescence optical microscopy and luminescence spectroscopy that revealed integration of the MOFs in the cell wall of the three fungal species. Fluorescence light microscopy images also showed that MOF particles are also transported to the intracellular region of the fungi and are stored in the vacuoles. The internalization of the MOFs in the intracellular region of the fungi opens a vast field for the application of these materials in the treatment of infectious fungi. To produce biomorphic materials, the biohybrids of the fungus Phialomyces macrosporus and titanium oxide (anatase) were submitted to a hydrothermal treatment (100-140 ° C) in alkaline medium (10M NaOH solution). The XRD measurements associated with SEM images, transmission electron microscopy (TEM) and X-ray dispersive energy (EDS) showed the production of microtubes made from sodium titanate nanotubes. The variation of NaOH concentration (6.5 to 8.0 M) allowed the formation of microtubes composed of sodium titanate nanoribbons. A mechanism has been proposed for the formation of nanoribbons on the biomorphic structure that takes into account the slow degradation of the cell wall components and adhesive substances that keeps the TiO₂ particles bound to the fungal hyphae.