Scientists have discovered flagella in an unexpected place: hot spring-dwelling bacteria from the phylum Chloroflexota. Research shows that flagella were lost in other forms of Chloroflexota that adapted to marine environments hundreds of millions of years ago.
Within the archaeal domain, there is a group of tiny hitchhikers. These organisms are abundant and yet exceptionally small, with mini genomes to match. To fill in their nutrient gaps, they must latch onto a larger host — often, a fellow archaeal microbe. Recently, researchers used population genomics to find that while archaeal hitchhikers may often act as parasites, in other cases, they likely help their hosts.
In the last thirty years, in environments all over the world, scientists have discovered giants among viruses. Culturing studies have been key to understanding these viruses’ host range, morphological structures, and infection strategies. More recently, researchers have employed cultivation-independent approaches to discover thousands of new giant viruses, rapidly expanding the diversity of the Nucleocytoviricota phylum. A new review provides a perspective on giant virus diversity, and how sequencing and bioinformatics have sped up the study of giant viruses.
In Cell Genomics, an international consortium led by researchers at the Joint Genome Institute team generated 824 new Actinobacteria genomes, which were were combined with nearly 5,000 publicly available ones and 1,100 metagenome-assembled genomes (MAGs) reconstructed from sequenced environmental samples in a previous study.
In Science, a team led by Jean-Marie Volland, a scientist with joint appointments at the DOE Joint Genome Institute (JGI) and the Laboratory for Research in Complex Systems, and Silvina Gonzalez-Rizzo and Olivier Gros of the Université des Antilles, described the morphological and genomic features of a giant filamentous bacterium, along with its life cycle.