Solvent extraction and purification of sugars from hemicellulose hydrolysates using boronic acid carriers

Research was performed to determine whether it was technically feasible to use boronic acid extractants to purify and concentrate the sugars present in hemicellulose hydrolysates. Initially, five types of boronic acids (phenylboronic acid, 3,5-dimethylphenylboronic acid, 4-tert-butylphenylboronic acid, trans-β-styreneboronic acid or naphthalene-2-boronic acid) dissolved in an organic diluent (Shellsol® 2046 or Exxal® 10) containing the quaternary amine Aliquat® 336 were tested for their ability to extract sugars (fructose, glucose, sucrose and xylose) from a buffered, immiscible aqueous solution. Naphthalene- 2-boronic acid was found to give the greatest extraction of xylose regardless of which diluent was used. Trials were then conducted to extract xylose and glucose from solutions derived from the dilute acid hydrolysis of sugar cane bagasse and to then strip the loaded organic solutions using an aqueous solution containing hydrochloric acid. This produced a strip solution in which the xylose concentration had been increased over 7× that of the original hydrolysate while reducing the concentration of the undesirable acid-soluble lignin by over 90%. Hence, this process can be exploited to produce high concentration xylose solutions suitable for direct fermentation.

Homogeneous isolation of nanocelluloses by controlling the shearing force and pressure in microenvironment

Nanocelluloses were prepared from sugarcane bagasse celluloses by dynamic high pressure microfluidization (DHPM), aiming at achieving a homogeneous isolation through the controlling of shearing force and pressure within a microenvironment. In the DHPM process, the homogeneous cellulose solution passed through chambers at a higher pressure in fewer cycles, compared with the high pressure homogenization (HPH) process. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) demonstrated that entangled network structures of celluloses were well dispersed in the microenvironment, which provided proper shearing forces and pressure to fracture the hydrogen bonds. Gel permeation chromatography (GPC), CP/MAS 13C NMR and Fourier transform infrared spectroscopy (FT-IR) measurements suggested that intra-molecular hydrogen bonds were maintained. These nanocelluloses of smaller particle size, good dispersion and lower thermal stability will have great potential to be applied in electronics devices, electrochemistry, medicine, and package and printing industry. © 2014 Elsevier Ltd.

Preparation of pH- and salinity-responsive cellulose copolymer in ionic liquid

A novel biodegradable pH- and salinity-responsive cellulose copolymer was prepared by grafting 2-(Dimethylamino) ethylmethacrylate (DMAEMA) onto bagasse cellulose in ionic liquid. The grafting polymerization was achieved in 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) under microwave irradiation. Copolymers were then characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction and thermo gravimetric analysis measurements. The results revealed that polymer chains had been successfully bonded to the cellulose backbone. Furthermore, the self-assembly of cellulose-g-DMAEMA copolymers at various salt concentrations and pH solution were investigated by means of swelling behavior measurement. It indicated that the copolymers presented dual pH and salinity-responsive properties. The synthetic strategy showed great potential in the modification of other cellulosic biomass to afford new biomaterials with desired properties. © 2014 Springer Science+Business Media Dordrecht.

Evaluation of yield parameters and nutritional aspects of different strains of oyster (Pleurotus ostreatus) mushroom

The present study investigates the comparison between three different strains of oyster mushroom Pleurotus ostreatus (oyster (local), WC-537, WC-522) regarding to their yield and nutritional aspects. Four different kinds of substrates (corncob, wheat straw, rice straw, and sugarcane bagasse) were used for the growth of oyster. Oyster strain on corncob was found to be the fast mycelial run in comparison with WC-537 and WC-522. WC-522 on sugarcane bagasse showed the slowest mycellial run. Highest number of flushes was produced by oyster strain on each substrate. Number of days for period between flushes for oyster and WC-537 was about equal on corn cob, wheat straw and rice straw i.e. 4-6 days. Number of days taken for maturation of fruiting bodies of oyster and WC-537 was almost equal 6-7 days. In terms of nutritional aspects all strains have almost the same amount of moisture, fat, ash, fiber and protein with small variation. All the strains have protein content of about 20% by weight.