title: Simultaneous production of endo-beta-1,4-xylanase and branched xylooligosaccharides by Thermomyces lanuginosus.
abstract: When grown on beech-wood glucuronoxylan, two strains of the thermophilic fungus Thermomyces lanuginosius, IMI 84400 and IMI 96213, secreted endo-beta-1,4-xylanase of glycoside hydrolase family 11 and simultaneously accumulated an acidic pentasaccharide in the medium. The aldopentaouronic acid was purified and its structure was established by a combination of NMR spectroscopy and enzyme digestion with glycosidases as MeGlcA(3)Xyl(4). Both strains showed limited growth on wheat arabinoxylan as a carbon source. An essential part of the polysaccharide was not utilized, and it was converted to a series of arabinoxylooligosaccharides differing in the degree of polymerization. The structure of the shorter arabinoxylooligosaccharides remaining in the wheat arabinoxylan-spent medium was established using mass spectrometry and digestion with glycosidases. Xylose and linear beta-1,4-xylooligosaccharides generated extracellularly during growth on either hardwood or cereal xylan were efficiently taken up by the cells and metabolized intracellularly. The data suggest that due to a lack of extracellular beta-xylosidase, alpha-glucuronidase, and alpha-l-arabinofuranosidase, the widely used T. lanuginosus strains might become efficient producers of branched xylooligosaccharides from both types of xylans.
authors.affiliation: Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava 45, Slovak Republic.
authors.forename: Vladimír
authors.initials: V
authors.lastname: Puchart
authors.forename: Peter
authors.initials: P
authors.lastname: Biely
mesh_terms: D001203:Ascomycota / Q000201:enzymology / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D043364:Endo-1,4-beta Xylanases / Q000096:biosynthesis*; D006026:Glycoside Hydrolases / Q000378:metabolism; D025942:Oligosaccharides, Branched-Chain / Q000096:biosynthesis* / Q000737:chemistry; D014908:Triticum / Q000378:metabolism; D014990:Xylans / Q000378:metabolism
chemical_list: D025942:Oligosaccharides, Branched-Chain; D014990:Xylans; C038910:glucuronoxylan; C085118:arabinoxylan; D006026:Glycoside Hydrolases; D043364:Endo-1,4-beta Xylanases