Ashabil Aygan

Synthesis of a Novel m-Substituted Poly(phenoxy-imine) and Investigation of its Fluorescence and Some Properties

Oxidative polycondensation of 3-((2-phenylhydrazono)methyl)phenol (3-PHMP), a new m-substituted poly(phenoxy-imine), was studied using oxidants such as sodium hypochlorite, air (O2) and hydrogen peroxide in an aqueous alkaline medium under various polymerization conditions. The macromolecular structure and optical properties of the polymer were characterized with elemental analysis, Size Exclusion Chromatography (SEC), Fourier Transform Infrared (FTIR), Nuclear Magnetic Resonance (NMR), absorption and fluorescence spectroscopy techniques. As a result of fluorescence measurement, the fluorescence lifetime of poly(3-PHMP) in DMF was calculated as 2.88 ns (χ2= 1.12). An electrochemical property the monomer and polymer were also studied using Cyclic Voltammetry (CV) technology. According to the CV measurements, the electrochemical band gaps (Eg′) of 3-PHMP and poly(3-PHMP) were found to be 2.64 and 1.94 eV, respectively. Electrical conductivity of the polymer was measured by the four-point probe technique. The electrical conductivity of poly(3-PHMP) was found to be ∼3.2 × 10−2S/cm. Thermo Gravimetric Analysis (TGA) revealed poly(3-PHMP) to be stable against thermo-oxidative decomposition. In addition, the in vitro antimicrobial activities of the synthesized compounds were tested on various microorganisms.

Coexpression of rumen fungal xylanase and bifunctional cellulase genes in Escherichia coli

ABSTRACT Rumen fungi inhabit the gastro-intestinal tract of ruminants and the most non-ruminant herbivores. Rumen fungi produce highly active plant cell wall degrading enzymes, therefore they have gained scientific interest. In this study, genes encoding xylanase (xynA-7) and cellulase (celA-5) were amplified from Neocallimastix sp. GMLF7 and Orpinomyces sp. GMLF5, respectively, and expressed in Escherichia coli. XynA-7 was found to be active only on xylan, however CelA-5 had activity both on carboxymethyl cellulose and lichenan. Lichenase activity of CelA-5 was found to be higher than carboxymethyl cellulase activity. The optimal conditions were at pH 6.0 and 40 ° C for CelA-5 and at pH 6.5 and 50 ° C for XynA-7. A coexpression vector was constructed to coproduce the XynA-7 and CelA-5 and then transformed into E. coli. The ability of the transformed E. coli strain to produce CMCase, xylanase and lichenase was evaluated. The transformed E. coli strain acquired the capacity to degrade CMC, xylan and lichenan.