We often imagine bacteria as microscopic isolated cells or colonies. But what if some defy this common perception? Dr. Gros and Dr. Volland join us on this episode to discuss their discovery of an unusually large, sulfur-oxidizing bacterium with a complex membrane organization and predicted life cycle.

Located in a mangrove swamp, the bacterium, named Candidatus Thiomargarita magnifica, astounded the researchers. While most bacterial species have cells around 2 micrometers in length, this extraordinary bacterium has an average cell length exceeding 9000 micrometers, making it visible to the naked eye!

Through the application of various microscopy techniques and genome sequencing, Dr. Gros and Dr. Volland observed highly polyploid cells with DNA and ribosomes compartmentalized within membranes. They also discovered a fascinating dimorphic life cycle where chromosomes are asymmetrically segregated into daughter cells.

These groundbreaking findings challenge traditional concepts of bacterial cells. The scientists reveal how these characteristics, along with the compartmentalization of genomic material and ribosomes in translationally active organelles, indicate a gain of complexity in the Thiomargarita lineage.

Don't miss this intriguing episode exploring the boundaries of what we know about bacterial cells and their potential complexity.

Keywords: Dr. Gros, Dr. Volland, Candidatus Thiomargarita magnifica, Megabacterium, Polyploid cells, Bacterial cell complexity, Genome sequencing, Asymmetric segregation, Microscopy.

A centimeter-long bacterium with DNA contained in metabolically active, membrane-bound organelles https://doi.org/10.1126/science.abb3634