Metagenomic insights into the rumen microbial fibrolytic enzymes in Indian crossbred cattle fed finger millet straw
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- 作者：V. Lyju Jose ; Thulasi Appoothy ; Ravi P. More ; A. Sha Arun
- 关键词：Rumen ; Fibrolytic enzymes ; Plant polysaccharides ; Metagenomics ; Microbiome
- 刊名：AMB Express
- 出版年：2017
- 出版时间：December 2017
- 年：2017
- 卷：7
- 期：1
- 全文大小：4512KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Microbiology; Microbial Genetics and Genomics; Biotechnology;
- 出版者：Springer Berlin Heidelberg
- ISSN：2191-0855
- 卷排序：7
文摘
The rumen is a unique natural habitat, exhibiting an unparalleled genetic resource of fibrolytic enzymes of microbial origin that degrade plant polysaccharides. The objectives of this study were to identify the principal plant cell wall-degrading enzymes and the taxonomic profile of rumen microbial communities that are associated with it. The cattle rumen microflora and the carbohydrate-active enzymes were functionally classified through a whole metagenomic sequencing approach. Analysis of the assembled sequences by the Carbohydrate-active enzyme analysis Toolkit identified the candidate genes encoding fibrolytic enzymes belonging to different classes of glycoside hydrolases(11,010 contigs), glycosyltransferases (6366 contigs), carbohydrate esterases (4945 contigs), carbohydrate-binding modules (1975 contigs), polysaccharide lyases (480 contigs), and auxiliary activities (115 contigs). Phylogenetic analysis of CAZyme encoding contigs revealed that a significant proportion of CAZymes were contributed by bacteria belonging to genera Prevotella, Bacteroides, Fibrobacter, Clostridium, and Ruminococcus. The results indicated that the cattle rumen microbiome and the CAZymes are highly complex, structurally similar but compositionally distinct from other ruminants. The unique characteristics of rumen microbiota and the enzymes produced by resident microbes provide opportunities to improve the feed conversion efficiency in ruminants and serve as a reservoir of industrially important enzymes for cellulosic biofuel production.