Roadmap for naming uncultivated Archaea and Bacteria

Enigmatic, ultrasmall, uncultivated Archaea.

Metagenomics has provided access to genomes of as yet uncultivated microorganisms in natural environments, yet there are gaps in our knowledge-particularly for Archaea-that occur at relatively low abundance and in extreme environments. Ultrasmall cells (<500 nm in diameter) from lineages without cultivated representatives that branch near the crenarchaeal/euryarchaeal divide have been detected ...

“Altiarchaeales”: Uncultivated Archaea from the Subsurface

Due to the limited cultivability of the vast majority of microorganisms, researchers have applied environmental genomics and other state-of-the-art technologies to gain insights into the biology of uncultivated Archaea and bacteria in their natural biotope. In this review, we summarize the scientific findings on a recently proposed order-level lineage of uncultivated Archaea called Altiarchaeal...

Are Uncultivated Bacteria Really Uncultivable?

Many strategies have been used to increase the number of bacterial cells that can be grown from environmental samples but cultivation efficiency remains a challenge for microbial ecologists. The difficulty of cultivating a fraction of bacteria in environmental samples can be classified into two non-exclusive categories. Bacterial taxa with no cultivated representatives for which appropriate lab...

Microscopy studies on uncultivated magnetotactic bacteria

Magnetotactic bacteria are characterized by the magnetosome, a membrane-bound, nano-sized organelle containing a magnetic crystal. This organelle is believed to help the bacteria to navigate along the geomagnetic field lines and find a preferred habitat for survival. The magnetosome is a biomineral structure highly controlled by the bacteria, composed of either magnetite (Fe3O4) or greigite (Fe...

Systematics of Archaea and Bacteria