Xylan is the third most abundant glycopolymer on earth after cellulose and chitin. As a major component of wood, grain and forage, this natural biopolymer has far-reaching impacts on human life. This highly acetylated cell wall polysaccharide is a vital component of the plant cell wall, which functions as a molecular scaffold, providing plants with mechanical strength and flexibility. Mutations...

Neurospora crassa 870 produced 14 and 0.025 U of extracellular xylanase (1,4-beta-d-xylan xylanohydrolase; EC 3.2.1.8) and beta-xylosidase (1,4-beta-xylan xylohydrolase; EC 3.2.1.37) per ml, respectively, in 4 days when commercial xylan was used as a carbon source. The effects of pH and carbon sources on xylanase production by N. crassa are discussed. Two xylanases (I and II) were purified and ...

BACKGROUND Among themophilic consolidated bioprocessing (CBP) candidate organisms, environmental isolates of Clostridium clariflavum have demonstrated the ability to grow on xylan, and the genome of C. clariflavum DSM 19732 has revealed a number of mechanisms that foster solubilization of hemicellulose that are distinctive relative to the model cellulolytic thermophile Clostridium thermocellum....

Garden asparagus (Asparagus officinalis L.) is a commercially important crop species utilized for its excellent source of vitamins, minerals and dietary fiber. However, after harvest the tissue hardens and its quality rapidly deteriorates because spear cell walls become rigidified due to lignification and substantial increases in heteroxylan content. This latter observation prompted us to inves...

Thermomonospora fusca chromosomal DNA was partially digested with EcoRI to obtain 4- to 14-kilobase fragments, which were used to construct a library of recombinant phage by ligation with EcoRI arms of lambda gtWES. lambda B. A recombinant phage coding for xylanase activity which contained a 14-kilobase insert was identified. The xylanase gene was localized to a 2.1-kilobase SalI fragment of th...

Xylanase J of alkaliphilic Bacillus sp. strain 41M-1 contains a carbohydrate-binding module family 36 xylan-binding domain (XBD). Mutational analysis of the XBD revealed that Tyr237, Asp313, Trp317, and Asp318 were involved in Ca(2+)-dependent xylan-binding, and that Asp313 and Asp318 were especially important.

The draft genome of Clostridium beijerinckii strain Ne1 was reconstructed from the metagenomic sequence of a mixed-microbial consortium that produced commercially significant quantities of hydrogen from xylan as a sole feedstock. The organism possesses relatively limited hemicellulolytic capacity and likely requires the action of other organisms to completely degrade xylan.

The main purpose of this study was to optimize microwave assisted alkaline extraction of the hemicellulose, xylan, from birch wood. The simultaneous effects of process variables such as time (10 30 minutes), concentration of sodium hydroxide solution (4 8 wt%), solid to liquid ratio (1:8 to 1:20, g:mL), and sample size (5 10 g) on the temperature of the wood slurry, wood dissolution, and yield ...

A xylanase gene, xynX, of Clostridium thermocellum had one thermostabilizing domain (TSD) between the signal peptide sequence and the catalytic domain (CD). The TSD of a truncated xylanase gene, xynX'(TSD-CD), was transpositioned from the N terminus to the C terminus of the CD by overlapping PCRs, and a modified product, xynX'(CD-TSD), was constructed. XynX'(TSD-CD) had a higher optimum tempera...