Xylose In Media Research Articles

Simple and Efficient Furfural Production from Xylose in Media Containing 1-Butyl-3-Methylimidazolium Hydrogen Sulfate

The acidic 1-butyl-3-methylimidazolium hydrogen sulfate ((bmim)(HSO4)) ionic liquid was explored as both a reaction medium and a catalyst in the furfural production from xylose. Preliminary experiments were carried out at 100−140 °C for 15−480 min in systems containing just xylose dissolved in (bmim)(HSO4) in the absence of externally added catalysts. More than 95% xylose conversion was achieved when operating at 120 or 140 °C for 300 and 90 min, respectively; but just 36.7% of the initial xylose was converted to furfural. Operation in biphasic reaction systems (in the presence of toluene, methyl-isobutyl ketone or dioxane as extraction solvents) at 140 °C under selected conditions resulted in improved furfural production (73.8%, 80.3%, and 82.2% xylose conversion to furfural for the cited extraction solvents, respectively).

Ethanol production during D-xylose, L-arabinose, and D-ribose fermentation by Bacteroides polypragmatus

The specific growth rate (μ) during cultivation of Bacteroides polypragmatus in 2.51 batch cultures in 4–5% (w/v) l-arabinose medium was 0.23 h-1 while that in either d-xylose or d-ribose medium was lower (μ=0.19 h-1). Whereas growth on arabinose or xylose occurred after about 6–8 h lag period, growth on ribose commenced after a 30 h lag phase. The maximum substrate utilization rate for arabinose, ribose and xylose in media with an initial substrate concentration of 4–5% (w/v) was 0.77, 0.76, and 0.60 g/l/h respectively. In medium containing a mixture of glucose, arabinose, and xylose, the utilization of all three substrates occurred concurrently. The maximum amount of ethanol produced after 72 h growth in 4–5% (w/v) of arabinose, xylose, and ribose was 9.4, 6.5, and 5.3 g/l, respectively. The matabolic end products (mol/mol substrate) of growth in 4.4% (w/v) xylose medium were 0.73 ethanol, 0.49 acetate, 1.39 CO2, 1.05 H2, and 0.09 butyrate.