TITLE:
Functional Metagenomics from the Rumen Environment—A Review
AUTHORS:
Wondimagegne Bekele, Abiy Zegeye, Addis Simachew, Getnet Assefa
KEYWORDS:
DNA Isolation, DNA Library Construction, Functional Screening
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.12 No.5,
May
31,
2021
ABSTRACT: The rumen microbiome plays an essential role in
ruminant physiology, nutrition and pathology as well as host immunity. A better
understanding of rumen microbial processes
and identification of which populations are responsible for specific functions
within the rumen microbiome will lead to better management and sustainable
utilization of the available feed base while maintaining a low environmental impact.
Recent advance in the culture independent method of microbiology such as
metagenomics, unravels potentially the rumen microbial process. There
are two basic types of metagenomics studies: Sequence-based and function-based
metagenomics. Sequence-based metagenomics involves sequencing and analysis of
DNA from environmental samples. Its purpose is to assemble genomes, identify
genes, find complete metabolic pathways, and compare organisms of different
communities. Whereas functional metagenomics is the study of the collective
genome of a microbial community by expressing it in a foreign host usually Escherichia coli (E. coli). It is a promising approach unearthing novel enzymes even from yet to culture
rumen microbiota. Further advances in the screening techniques promise vast
opportunities to rumen microbiologists, and animal nutritionist. The
identification of novel enzyme through functional metagenomics consists of
three parts: rumen sample collection; DNA library construction and screening of
individual clone. Functional metagenomics was successfully applied to identify
different antibiotics, hydrolytic enzymes, antibiotic resistance genes, and
many other functions; moreover, it allowed characterization of genes encoding
enzymes with a particular activity, which represents completely novel sequence.
There are a number of outputs from functionally screened rumen product such as
carbohydrate active enzymes (CAZymes) that can break down plant cell walls.
Company involved commercialization of metagenomics research such as Syngenta,
Genencor International, BRAIN etc., has produced many biological molecules of
commercial interest. The aim of this paper is to elucidate functional
metagenomics, from rumen environment and its potential for commercial purpose.