Electrically conductive nano graphite-filled bacterial cellulose composites.

A unique three dimensional (3D) porous structured bacterial cellulose (BC) can act as a supporting material to deposit the nanofillers in order to create advanced BC-based functional nanomaterials for various technological applications. In this study, novel nanocomposites comprised of BC with exfoliated graphite nanoplatelets (xGnP) incorporated into the BC matrix were prepared using a simple particle impregnation strategy to enhance the thermal properties and electrical conductivity of the BC. The flake-shaped xGnP particles were well dispersed and formed a continuous network throughout the BC matrix. The temperature at 10% weight loss, thermal stability and residual ash content of the nanocomposites increased at higher xGnP loadings. The electrical conductivity of the composites increased with increasing xGnP loading (attaining values 0.75 S/cm with the addition of 2 wt.% of xGnP). The enhanced conductive and thermal properties of the BC-xGnP nanocomposites will broaden applications (biosensors, tissue engineering, etc.) of BC and xGnP.

Biosynthesis of bacterial cellulose in the presence of different nanoparticles to create novel hybrid materials.

The unique micro-nano porous three-dimensional network of bacterial cellulose (BC) can facilitate the incorporation of nanoparticles (NPs) into the BC matrix to create advanced BC-based functional nanomaterials for diverse applications. In this study, novel nanomaterials comprised of bacterial cellulose (BC) synthesized in the presence of different NPs (cellulose nanofibrils (CNF), exfoliated graphite nanoplatelets (xGnP), and nanoclay (NC)) were prepared using an in situ approach. NPs at 0.5 wt.% loading were added into the BC culture medium and their effect on the resulting nanocomposite structure was studied by field emission scanning electron microscopy (FE-SEM), X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). All BC-based nanomaterials produced, exhibited good dispersion of the NPs within the BC matrix and the NPs were found embedded among the voids and microfibrils. The thermal stability and residual mass of BC-xGnP and BC-NC nanomaterials was significantly increased compared with the neat BC. CNF incorporation into the BC matrix did not change the thermal stability and residual mass of the BC matrix. This study also provides novel insights into the properties of the hybrid materials, and shows the approach used to make these materials which results in increased performance for chosen applications.

The plant cell wall-decomposing machinery underlies the functional diversity of forest fungi.

Brown rot decay removes cellulose and hemicellulose from wood--residual lignin contributing up to 30% of forest soil carbon--and is derived from an ancestral white rot saprotrophy in which both lignin and cellulose are decomposed. Comparative and functional genomics of the "dry rot" fungus Serpula lacrymans, derived from forest ancestors, demonstrated that the evolution of both ectomycorrhizal biotrophy and brown rot saprotrophy were accompanied by reductions and losses in specific protein families, suggesting adaptation to an intercellular interaction with plant tissue. Transcriptome and proteome analysis also identified differences in wood decomposition in S. lacrymans relative to the brown rot Postia placenta. Furthermore, fungal nutritional mode diversification suggests that the boreal forest biome originated via genetic coevolution of above- and below-ground biota.