Microbial dark matter coming to light: challenges and opportunities.

Notably, single-amplified genomes (SAGs) and metagenome-assembled genomes (MAGs) obtained from single-cell genomic and metagenomic approaches, respectively, have become the most effective methods that enable organism-level genomic analysis of complex microbial ecosystems without the need for cultivation, which brings lighttoMDM. Hug et al. used more than 1000 MDM genomes, together with public genomic data,toinferthetreeoflifeanddescribed a hyper-diverse clade of MDM termed the Candidate Phyla Radiation (CPR), subdividing the domain Bacteria [4]. The study of MDM is still in its infancy and further exploration of MDM will continue to provide unanticipated and excitinganswersabouttheevolutionand roles of MDM in nature. This is so-called Microbial Dark Matter (MDM): the enormous diversity of yet-uncultivated microbes that microbiologists can only study by using cultivation-independent techniques. [Extracted from the article]