High Genetic Diversity of Microbial Cellulase and Hemicellulase Genes in the Hindgut of Holotrichia parallela Larvae.
High Genetic Diversity of Microbial Cellulase and Hemicellulase Genes in the Hindgut of Holotrichia parallela Larvae.
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平行黑鳃金龟幼虫后肠微生物纤维素酶和半纤维素酶基因的高遗传多样性
DOI：
10.3390/ijms160716545
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发表时间：
2015-07-21
影响因子：
5.6
通讯作者：
Zhang H
中科院分区：
文献类型：
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作者：
Sheng P;Li Y;Marshall SD;Zhang H
本研究采用不依赖培养的文库构建和测序方法，对暗黑鳃金龟（Holotrichia parallela）幼虫后肠细菌群落纤维素酶和半纤维素酶基因的遗传多样性进行了分析。这些结果表明，在黑腹菌后肠中存在大量的、多样的编码木质纤维素水解酶的细菌基因。parallela。总共有101个不同的基因片段（相似性<95%）的糖基水解酶家族，包括GH 2（24个基因），GH8（27个基因），GH10（19个基因），GH11（14个基因）和GH36检索了17个基因家族，并对GH2的某些序列进行了分析。GH8（10.61%）、GH11（18.42%）和GH11（3.33%）与GenBank中已知序列的同源性均小于60%，表明它们是新的。基于系统发育分析，半纤维素酶家族的序列与拟杆菌门和厚壁菌门的酶相关。来自纤维素酶家族的片段大多与变形菌门相关。此外，获得了全长内切木聚糖酶基因，并且该酶在广泛的pH水平范围内表现出活性。结果表明，黑腹小蠹后肠中存在大量的纤维素分解菌和木聚糖分解菌。这些共生细菌在寄主昆虫降解根系和其他有机物方面发挥着重要作用。
In this study, we used a culture-independent method based on library construction and sequencing to analyze the genetic diversity of the cellulase and hemicellulase genes of the bacterial community resident in the hindgut of Holotrichia parallela larvae. The results indicate that there is a large, diverse set of bacterial genes encoding lignocellulose hydrolysis enzymes in the hindgut of H. parallela. The total of 101 distinct gene fragments (similarity <95%) of glycosyl hydrolase families including GH2 (24 genes), GH8 (27 genes), GH10 (19 genes), GH11 (14 genes) and GH36 (17 genes) families was retrieved, and certain sequences of GH2 (10.61%), GH8 (3.33%), and GH11 (18.42%) families had <60% identities with known sequences in GenBank, indicating their novelty. Based on phylogenetic analysis, sequences from hemicellulase families were related to enzymes from Bacteroidetes and Firmicutes. Fragments from cellulase family were most associated with the phylum of Proteobacteria. Furthermore, a full-length endo-xylanase gene was obtained, and the enzyme exhibited activity over a broad range of pH levels. Our results indicate that there are large number of cellulolytic and xylanolytic bacteria in the hindgut of H. parallela larvae, and these symbiotic bacteria play an important role in the degradation of roots and other organic matter for the host insect.