基于扩增子测序的瘤胃内含物中木聚糖酶基因多样性研究

采用高通量扩增子测序技术，对山羊瘤胃微生物宏基因组第10家族(GH10)和第11家族(GH11)木聚糖酶基因多样性进行分析.经序列拼接、过滤和可操作分类单元聚类(<95%),获得348个GH10木聚糖酶基因. GH10木聚糖酶基因片段与GenBank数据库中已知蛋白序列的一致性为46%～97%,其中一半以上的序列与已知木聚糖酶的一致性低于80%.序列注释结果表明，GH10木聚糖酶基因分布于5个门，其中拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes)为优势门.经序列处理分析，获得143个GH11木聚糖酶基因，与GenBank中已知蛋白序列的一致性为51%～100%. GH11木聚糖酶基因分布于6个门，其中子囊菌门(Ascomycota)和放线菌门(Actinobacteria)为优势门.基于片段序列和染色体步移技术，获得两个新的全长木聚糖酶基因，由其编码的蛋白具有特殊的结构域组成.本研究表明，山羊瘤胃环境中GH10木聚糖酶基因的多样性远高于GH11,且两者的分布存在较大差异.此外，该环境中还存在大量的新木聚糖酶基因，可为后续木聚糖酶基因资源的发掘和应用奠定基...

Diversity research of xylanase genes in goat rumen contents demonstrated by amplicon sequencing

The rumen of ruminants contains a large number of microorganisms that can degrade xylan, but the degree of diversity has not been studied in depth. In this study, high-throughput amplicon sequencing technology was used to analyze the gene diversity of goat rumen microbes family 10 (GH10) and family 11 (GH11) xylanase. 348 OTUs were obtained from GH10 xylanase genes after sequence splicing, filtering and clustering of operable taxa (< 95%). The identity of the GH10 xylanase gene fragment with known protein sequences in GenBank was 46?97%, of which more than half of the sequences were less than 80% identical to known xylanases. Sequence annotation results showed that GH10 xylanase genes were distributed in 5 phyla, among which Bacteroidetes and Firmicutes were the dominant phyla, accounting for 98.9%. The GH11 xylanase gene sequencing sequence was processed in the same way to obtain 143 OTUs, and the identity with the known protein sequence in GenBank was 51?100%. GH11 xylanase genes were distributed in 6 phyla, among which Ascomycota and Actinobacteria were the dominant phyla, accounting for 84%. Two new full-length xylanase genes were obtained based on fragment sequences and chromosome walking techniques, and the encoded proteins had special domain composition. This study shows that high-throughput amplicon sequencing technology has the advantages of high coverage, low cost and low time-consuming for the study of xylanase gene diversity. The results showed that the diversity of GH10 xylanase genes in goat rumen environment was much higher than that of GH11, and there was a big difference in the distribution of the two. In addition, there are a large number of new xylanase genes in this environment, which can lay a foundation for the subsequent discovery and application of xylanase gene resources.