Activity-Based Metagenomic Screening and Biochemical Characterization of Bovine Ruminal Protozoan Glycoside Hydrolases


The rumen, the foregut of herbivorous ruminant animals such as cattle, functions as a bioreactor to process complex plant material. Among the numerous and diverse microbes involved in ruminal digestion are the ruminal protozoans, which are single-celled, ciliated eukaryotic organisms. An activity-based screen was executed to identify genes encoding fibrolytic enzymes present in the metatranscriptome of a bovine ruminal protozoan-enriched cDNA expression library. Of the four novel genes identified, two were characterized in biochemical assays. Our results provide evidence for the effective use of functional metagenomics to retrieve novel enzymes from microbial populations that cannot be maintained in axenic cultures.


Biological Sciences

Keywords and Phrases

Activity-Based; Axenic Culture; Biochemical Assay; Biochemical Characterization; Complex Plants; Eukaryotic Organisms; Genes Encoding; Glycoside Hydrolases; Metagenomics; Microbial Populations; Gene Expression; Mammals; Protozoa; Sugars; Enzymes; Glycosidase; Protozoal DNA; Protozoal Protein; Bioassay; Biochemistry; Bioreactor; Cattle; Ciliate; Enzyme Activity; Genomics; Herbivore; Microbial Activity; Animal; Cattle; Chemistry; Cluster Analysis; DNA Sequence; Gene Library; Genetics; Metabolism; Metagenome; Molecular Genetics; Nucleotide Sequence; Parasitology; Phylogeny; Ruminant Stomach; Sequence Homology; DNA, Protozoan; Molecular Sequence Data; Protozoan Proteins; Rumen; Sequence Analysis, DNA

International Standard Serial Number (ISSN)

0099-2240; 1098-5336

Document Type

Article - Journal

Document Version


File Type





© 2011 American Society for Microbiology, All rights reserved.

Publication Date

01 Nov 2011

PubMed ID