• Home
  • Search Results
  • Direct cloning, expression of a thermostable xylanase gene from the metagenomic DNA of cow dung compost and enzymatic production of xylooligosaccharides from corncob.

Direct cloning, expression of a thermostable xylanase gene from the metagenomic DNA of cow dung compost and enzymatic production of xylooligosaccharides from corncob.

Biotechnology letters (2015-05-23)
Ming-zhe Sun, Hong-chen Zheng, Ling-cai Meng, Jun-she Sun, Hui Song, Yun-juan Bao, Hai-sheng Pei, Zheng Yan, Xiu-qing Zhang, Jing-sheng Zhang, Yi-han Liu, Fu-ping Lu
ABSTRACT

To acquire a thermostable xylanase, that is suitable for xylooligosaccharide production from pretreated corncobs, the metagenomic method was used to obtain the gene from an uncultured environmental microorganism. A thermostable xylanase-encoding gene (xyn10CD18) was cloned directly from the metagenomic DNA of cow dung compost. When xyn10CD18 was expressed in Bacillus megaterium MS941, extracellular xylansae activity at 106 IU/ml was achieved. The purified recombinant Xyn10CD18 was optimally active at pH 7 and 75 °C as measured over 10 min. It retained over 55% of its initial activity at 70 °C and pH 7 after 24 h. Its action on birchwood xylan for 18 h liberated xylooligosaccharides with 2°-4° of polymerization, with xylobiose and xylotetraose as the main products. When pretreated corncobs were hydrolyzed by Xyn10CD18 for 18 h, the xylooligosaccharides (DP 2-4) products increased to 80% and the xylose was just increased by 3%. Xyn10CD18 is a thermostable endoxylanase and is a promising candidate for biomass conversion and xylooligosaccharide production.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
D-(+)-Xylose, ≥99%
Sigma-Aldrich
D-(+)-Xylose, BioXtra, ≥99%
Sigma-Aldrich
D-(+)-Xylose, ≥99%
Sigma-Aldrich
Sodium dodecyl sulfate solution, BioUltra, for molecular biology, 20% in H2O
Sigma-Aldrich
Sodium dodecyl sulfate solution, BioUltra, for molecular biology, 10% in H2O
Sigma-Aldrich
D-(+)-Xylose, BioUltra, ≥99.0% (sum of enantiomers, HPLC)
Supelco
Sodium dodecyl sulfate, dust-free pellets, suitable for electrophoresis, for molecular biology, ≥99.0% (GC)
Sigma-Aldrich
3,5-Dinitrosalicylic acid, used in colorimetric determination of reducing sugars
Sigma-Aldrich
Sodium dodecyl sulfate, ReagentPlus®, ≥98.5% (GC)
Sigma-Aldrich
Sodium dodecyl sulfate, BioXtra, ≥99.0% (GC)
Sigma-Aldrich
Sodium dodecyl sulfate, 92.5-100.5% based on total alkyl sulfate content basis
Sigma-Aldrich
Sodium dodecyl sulfate, BioReagent, suitable for electrophoresis, for molecular biology, ≥98.5% (GC)
Sigma-Aldrich
Sodium dodecyl sulfate, ≥99.0% (GC), dust-free pellets
Sigma-Aldrich
Sodium dodecyl sulfate, ACS reagent, ≥99.0%
Sigma-Aldrich
Sodium dodecyl sulfate, ≥90%
Sigma-Aldrich
Sodium dodecyl sulfate, tested according to NF, mixture of sodium alkyl sulfates consisting mainly of sodium dodecyl sulfate
Sigma-Aldrich
3,5-Dinitrosalicylic acid, 98%
Sigma-Aldrich
Sodium dodecyl sulfate, ≥98.0% (GC)
Sigma-Aldrich
Sodium dodecyl sulfate, BioUltra, for molecular biology, ≥99.0% (GC)
Sigma-Aldrich
Sodium dodecyl sulfate, BioReagent, suitable for electrophoresis, for molecular biology, ≥98.5% (GC), free-flowing, Redi-Dri