title: Hydrolysis of xylan at high temperature by co-action of the xylanase from Anoxybacillus flavithermus BC and the beta-xylosidase/alpha-arabinosidase from Sulfolobus solfataricus Oalpha.
abstract: OBJECTIVE
  It is evaluated the effectiveness of the combined action of two highly thermostable enzymes for the hydrolysis of xylans at high temperature in order to produce D-xylose.
  
  
  RESULTS
  Xylans from different sources were hydrolyzed at high degree at 70 degrees C by co-action of a xylanase from the thermophilic bacterium Anoxybacillus flavithermus BC and the novel beta-xylosidase/alpha-arabinosidase from the hyperthermophilic crenarchaeon Sulfolobus solfataricus Oalpha. Beechwood xylan was the best substrate among the xylans tested giving, by incubation only with xylanase, 32.8 % hydrolysis after 4 h. The addition of the beta-xylosidase/alpha-arabinosidase significantly improved the rate of hydrolysis, yielding 63.6% conversion after 4 h incubation, and the main sugar identified was xylose.
  
  
  CONCLUSIONS
  This study demonstrates that a significant degree of xylan degradation was reached at high temperature by co-action of the two enzymes. Xylose was obtained as a final product in considerable yield.
  
  
  CONCLUSIONS
  Although the xylan represents the second most abundant polysaccharide in nature, it still doesn't have significant utilization for the difficulties encountered in its hydrolysis. Its successful hydrolysis to xylose in only one stage process could make of it a cheap sugar source and could have an enormous economic potential for the conversion of plant biomass into fuels and chemicals.
authors.affiliation: Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
authors.forename: M
authors.initials: M
authors.lastname: Kambourova
authors.forename: R
authors.initials: R
authors.lastname: Mandeva
authors.forename: I
authors.initials: I
authors.lastname: Fiume
authors.forename: L
authors.initials: L
authors.lastname: Maurelli
authors.forename: M
authors.initials: M
authors.lastname: Rossi
authors.forename: A
authors.initials: A
authors.lastname: Morana
mesh_terms: D001406:Bacillaceae / Q000201:enzymology* / Q000254:growth & development; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004187:Disaccharides / Q000032:analysis; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism*; D005959:Glucosidases / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D006358:Hot Temperature; D006868:Hydrolysis; D048229:Sulfolobus solfataricus / Q000201:enzymology*; D014312:Trisaccharides / Q000032:analysis; D014990:Xylans / Q000032:analysis / Q000378:metabolism*; D014994:Xylose / Q000032:analysis
chemical_list: D004187:Disaccharides; D014312:Trisaccharides; D014990:Xylans; C515044:xylotriose; C008317:maltotriose; D014994:Xylose; D005959:Glucosidases; D006026:Glycoside Hydrolases; C104851:Sulfolobus solfataricus beta-glycosidase; C019713:alpha-N-arabinofuranosidase; D043364:Endo-1,4-beta Xylanases; C004173:xylobiose