MUTANT XYLANASE, MANUFACTURING METHOD AND USE THEREFOR, AND METHOD FOR MANUFACTURING SACCHARIFIED LIGNOCELLULOSE

• Main Authors: INOUE, ATSUSHI, OKAKURA, KAORU, TAMAI, HIROKI, YANAI, HISAAKI, YOKOYAMA, FUMIKAZU, OSABE, MASAMI
• Format: Patent
• Language: English; French; Japanese
• Published: 30.05.2013
• Subjects: ANIMAL AND VEGETABLE OILS, FATS, FATTY SUBSTANCES AND WAXES; BAKERY PRODUCTS; BAKING; BEER; BIOCHEMISTRY; BLEACHING LEATHER OR FURS; CANDLES; CHEMISTRY; COMPOSITIONS THEREOF; CULTURE MEDIA; DETERGENT COMPOSITIONS; DETERGENTS; DRY-CLEANING, WASHING OR BLEACHING FIBRES, FILAMENTS, THREADS,YARNS, FABRICS, FEATHERS OR MADE-UP FIBROUS GOODS; EDIBLE DOUGHS; ENZYMOLOGY; FATTY ACIDS THEREFROM; FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIREDCHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERSFROM A RACEMIC MIXTURE; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR; FODDER; FOODS OR FOODSTUFFS; HUMAN NECESSITIES; LAUNDERING; METALLURGY; MICROBIOLOGY; MICROORGANISMS OR ENZYMES; MUTATION OR GENETIC ENGINEERING; PRESERVATION THEREOF; PROPAGATING, PRESERVING OR MAINTAINING MICROORGANISMS; RECOVERY OF GLYCEROL; RESIN SOAPS; SOAP OR SOAP-MAKING; SPIRITS; TEXTILES; THEIR TREATMENT, NOT COVERED BY OTHER CLASSES; TREATMENT OF TEXTILES OR THE LIKE; TREATMENT, e.g. PRESERVATION, OF FLOUR OR DOUGH, e.g. BYADDITION OF MATERIALS; USE OF SINGLE SUBSTANCES AS DETERGENTS; VINEGAR; WINE

The present invention addresses the following problems: providing an inexpensive, efficient lignocellulose saccharification method using a thermostable xylanase; and providing a mutant xylanase that has a substituted amino-acid residue, exhibits stable activity even under harsh conditions in which enzymes are easily deactivated, and has an initial reaction rate not much less than that of the corresponding wild-type xylanase. A lignocellulose saccharification method that includes bringing a lignocellulose feedstock into contact with a thermostable xylanase; and a mutant xylanase that has a substituted amino-acid residue, has an initial reaction rate at least 70% of that of the corresponding wild-type xylanase, and, after a 24-hour heat treatment at 50°C, exhibits xylanase activity at least 50% of that exhibited before said heat treatment. La présente invention résout les problèmes suivants : description d'un procédé de saccharification de lignocellulose économique et efficace utilisant une xylanase thermostable ; et description d'une xylanase mutante qui a un résidu d'acide aminé substitué, présente une activité stable même dans des conditions rigoureuses dans lesquelles des enzymes sont aisément désactivées, et a un taux de réaction initial pas fortement inférieur à celui de la xylanase de type sauvage correspondante. Un procédé de saccharification de lignocellulose comprend la mise en contact d'une matière première de lignocellulose avec une xylanase thermostable ; et une xylanase mutante a un résidu d'acide aminé substitué, a un taux de réaction initial d'au moins 70 % de celui de la xylanase de type sauvage correspondante, et, après un traitement thermique de 24 heures à 50 °C, présente une activité xylanase d'au moins 50 % de celle présentée avant ledit traitement thermique.