Compared Approaches for Characterizing Rumen Microbiota: Culture-Based, Molecular, and Quantitative Perspectives

Abstract

A comprehensive understanding of rumen microbial communities is critical for improving feed efficiency, reducing methane emissions, and enhancing sustainable livestock production. Recent advances in molecular technologies have revolutionized the analysis of rumen microbiota, encompassing culture-based, molecular, and quantitative approaches. This review aimed to compare these approaches in order to provide a more comprehensive, accurate, and reliable understanding of rumen microbiota. Conventional culture-based techniques enable the direct isolation and physiological characterization of microorganisms, but they can identify only a limited proportion of microbes capable of growing under laboratory conditions. Molecular approaches allow comprehensive microbial profiling, although they are often semi-quantitative in nature. Among these, 16S rRNA gene-based methods provide detailed insights into the composition and diversity of microbial communities, including uncultured bacteria and archaea. Nevertheless, these methods are susceptible to amplification bias and generally lack absolute quantification. Quantitative polymerase chain reaction (qPCR), in contrast, offers sensitive and accurate absolute quantification of specific microbial targets but is limited to known microorganisms and requires appropriate standards. Metagenomics approaches provide the most comprehensive analysis by revealing both the taxonomic composition and potential genetic roles of microbial communities. However, metagenomics remains expensive, requires complex bioinformatics analysis, and typically does not provide absolute quantification without integration with other techniques. Therefore, contemporary rumen microbiome research commonly employs a combination of these techniques to obtain a more comprehensive understanding of the rumen ecosystem.