Characterization of the need for galactofuranose during the Neurospora crassa life cycle.

Galactofuranose is a constituent of the cell walls of filamentous fungi. The galactofuranose can be found as a component of N-linked oligosaccharides, in O-linked oligosaccharides, in GPI-anchored galactomannan, and in free galactomannan. The Neurospora genome contains a single UDP-galactose mutase gene (ugm-1/NCU01824) and two UDP-galactofuranose translocases used to import UDP-galactofuranose into the lumen of the Golgi apparatus (ugt-1/NCU01826 and ugt-2/NCU01456). Our results demonstrate that loss of galactofuranose synthesis or its translocation into the lumen of the secretory pathway affects the morphology and growth rate of the vegetative hyphae, the production of conidia (asexual spores), and dramatically affects the sexual stages of the life cycle. In mutants that are unable to make galactofuranose or transport it into the lumen of the Golgi apparatus, ascospore development is aborted soon after fertilization and perithecium maturation is aborted prior to the formation of the neck and ostiole. The Neurospora genome contains three genes encoding possible galactofuranosyltransferases from the GT31 family of glycosyltransferases (gfs-1/NCU05878, gfs-2/NCU07762, and gfs-3/NCU02213) which might be involved in generating galactofuranose-containing oligosaccharide structures. Analysis of triple KO mutants in GT31 glycosyltransferases shows that these mutants have normal morphology, suggesting that these genes do not encode vital galactofuranosyltransferases.

Chemical structure and biological activity of the (1 → 3)-linked ß-D-glucan isolated from marine diatom Conticribra weissflogii.

Several polysaccharides are considered to be "biological response modifiers" (BRM) - these refer to biomolecules that augment immune responses and can be derived from a variety of sources. Microalgae produce a diverse range of polysaccharides and could be an excellent source of BRM. Here, we describe the chemical structure and biological activity of water-soluble polysaccharide isolated from the marine diatom Conticribra weissflogii. Using chemical and NMR spectroscopic methods, the polysaccharide was identified as a (1 â†’ 3)-linked ß-D-glucan with a low proportion of C-6 substitution by single ß-glucose units. The biological activity of this low molecular weight ß-glucan (11.7 kDa) was investigated with respect to glioblastoma cell lines (U87 MG and U251) and macrophages (RAW 264.7). We observed that this ß-D-glucan did not exhibit cytotoxic activity against glioblastoma cells, but did enhance the phagocytic activity of macrophages, suggesting that it possesses immunomodulatory properties.

Adsorption of pharmaceuticals in water through lignocellulosic fibers synergism.

The contamination of water from disposal of drugs is an emerging problem due to their consequences on trophic webs. This study evaluated the ability of sugarcane and coconut fiber to reduce water toxicity contaminated by pharmaceuticals. The toxicity of solutions containing pharmaceuticals was studied by bioassay using Allium cepa, before and after filtration of contaminated water. The coconut and sugarcane fiber have not been satisfactory in reducing toxicity when tested separately. Despite no induction of chromosomal aberrations, our study found a reduction of the mitotic index. The mixture of fibers showed better results providing total reduction of toxicity, in addition to maintenance in the mitotic index and induction of chromosome aberrations. The interaction between fibers and drugs was confirmed by Thermogravimetry and Differential Thermal Analyses (TG/DTA) which presented differences in profile between the fibers before and after adsorption. The mixture of coconut and sugarcane proved viable for reduction of toxicity in contaminated water by a mixture of pharmaceuticals.