Molecular detection and diversity of xylanase genes in alpine tundra soil.
Xylan is a major polysaccharide in plant cell walls, and its degradation is mainly conducted by microbial xylanases in nature. To explore the xylanase diversity in the environment, two sets of degenerate primers were designed based on the microbial xylanase sequences in Pfam database of glycosyl hydrolase (GH) family 10 and 11 and were used to amplify objective gene fragments directly from the alpine tundra soil DNA of the Tianshan Mountains, China. Ninety-six distinct GH 10 and 31 GH 11 xylanase gene fragments were retrieved, and most of them have low identities with known sequences in GenBank. Based on phylogenetic analysis, all of the GH 10 xylanase sequences fell into six clusters and were related to xylanases from Actinobacteria, Proteobacteria, Verrucomicrobia, Bacteroidetes, Firmicutes, and Acidobacteria. Three clusters of GH 11 xylanase sequences were established, and two of them were related with enzymes from fungi. These results indicated the diversity of xylanase genes in this cold environment. Four xylanolytic strains were isolated from the soil, and GH 10 xylanase gene fragments were cloned using the same primers. A full-length gene was obtained and expressed in Escherichia coli, and the recombinant enzyme showed some cold-related characteristics. Our study provides an efficient molecular approach to study xylanase in complex environments and casts an insight into the diversity and distribution of xylanases in a cold environment, which is very meaningful to understand their roles in xylan degradation in nature.
Wang
Guozeng
G
Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Beijing 100081, People's Republic of China.
Wang
Yaru
Y
Yang
Peilong
P
Luo
Huiying
H
Huang
Huoqing
H
Shi
Pengjun
P
Meng
Kun
K
Yao
Bin
B
D000595:Amino Acid Sequence; D001419:Bacteria / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D044822:Biodiversity; D002681:China; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005658:Fungi / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D012988:Soil Microbiology; D014990:Xylans / Q000378:metabolism
D001426:Bacterial Proteins; D005656:Fungal Proteins; D014990:Xylans; D043364:Endo-1,4-beta Xylanases