Metagenomic DNA Extraction of Natural Cellulose-Degrading Consortia

A natural cellulose-degrading consortium is able to efficiently convert various types of lignocellulose to organic products, which is considered a potential method for the production of biofuels and biochemicals from lignocellulose materials. Metagenomics is an efficient method for determining the complex microbiota structure and performing metabolic mechanism analysis. However, natural cellulose-degrading consortia not only have complicated microbiome compositions and metabolites but also have tight adsorption between cells and cellulose fibers, which could have a significant influence on metagenomic DNA extraction, leading to a reduction of the DNA concentration, integrity, and diversity. Here, we found that bacterial cells that bind to cellulose fibers were efficiently washed off by a high-salt solution treatment and that the wall-breaking ratios of the biological enzyme and mechanical homogenization method were significantly higher than those of grinding and the freeze-thaw method. These results helped to establish a new method for extraction of the consortia metagenome that efficiently decreased absorption between cells and cellulose fibers, reduced the adverse impact of metabolites on DNA extraction, and improved the quality of DNA extraction.