Phylogenetic diversity and environment-specific distributions of glycosyl hydrolase family 10 xylanases in geographically distant soils.
BACKGROUND
Xylan is one of the most abundant biopolymers on Earth. Its degradation is mediated primarily by microbial xylanase in nature. To explore the diversity and distribution patterns of xylanase genes in soils, samples of five soil types with different physicochemical characters were analyzed.


RESULTS
Partial xylanase genes of glycoside hydrolase (GH) family 10 were recovered following direct DNA extraction from soil, PCR amplification and cloning. Combined with our previous study, a total of 1084 gene fragments were obtained, representing 366 OTUs. More than half of the OTUs were novel (identities of <65% with known xylanases) and had no close relatives based on phylogenetic analyses. Xylanase genes from all the soil environments were mainly distributed in Bacteroidetes, Proteobacteria, Acidobacteria, Firmicutes, Actinobacteria, Dictyoglomi and some fungi. Although identical sequences were found in several sites, habitat-specific patterns appeared to be important, and geochemical factors such as pH and oxygen content significantly influenced the compositions of xylan-degrading microbial communities.


CONCLUSIONS
These results provide insight into the GH 10 xylanases in various soil environments and reveal that xylan-degrading microbial communities are environment specific with diverse and abundant populations.
Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
Guozeng
G
Wang
Kun
K
Meng
Huiying
H
Luo
Yaru
Y
Wang
Huoqing
H
Huang
Pengjun
P
Shi
Peilong
P
Yang
Zhifang
Z
Zhang
Bin
B
Yao
D001419:Bacteria / Q000145:classification / Q000201:enzymology / Q000235:genetics; D002681:China; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D017753:Ecosystem; D043364:Endo-1,4-beta Xylanases / Q000145:classification / Q000235:genetics*; D005658:Fungi / Q000145:classification / Q000201:enzymology / Q000235:genetics; D014644:Genetic Variation; D005843:Geography; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D012987:Soil / Q000032:analysis; D012988:Soil Microbiology; D013045:Species Specificity
D004269:DNA, Bacterial; D004271:DNA, Fungal; D012987:Soil; D043364:Endo-1,4-beta Xylanases