According to small subunit ribosomal RNA (ss rRNA) sequence comparisons all known Archaea belong to the phyla Crenarchaeota, Euryarchaeota, and--indicated only by environmental DNA sequences--to the 'Korarchaeota'. Here we report the cultivation of a new nanosized hyperthermophilic archaeon from a submarine hot vent. This archaeon cannot be attached to one of these groups and therefore must represent an unknown phylum which we name 'Nanoarchaeota' and species, which we name 'Nanoarchaeum equitans'. Cells of 'N. equitans' are spherical, and only about 400 nm in diameter. They grow attached to the surface of a specific archaeal host, a new member of the genus Ignicoccus. The distribution of the 'Nanoarchaeota' is so far unknown. Owing to their unusual ss rRNA sequence, members remained undetectable by commonly used ecological studies based on the polymerase chain reaction. 'N. equitans' harbours the smallest archaeal genome; it is only 0.5 megabases in size. This organism will provide insight into the evolution of thermophily, of tiny genomes and of interspecies communication.

Although uptake into cells is highly complex and regulated, heterogeneous particle collectives are usually employed to deliver small interfering RNA (siRNA) to cells. Within these collectives, it is difficult to accurately identify the active species, and a decrease in efficacy is inherent to such preparations. Here, we demonstrate the manufacture of uniform nanoparticles with the deposition of siRNA on gold in a layer-by-layer approach, and we further report on the cellular delivery and siRNA activity as functions of surface properties.

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A novel coccoid, anaerobic, Fe2+-oxidizing archaeum was isolated from a shallow submarine hydrothermal system at Vulcano, Italy. In addition to ferrous iron, H2 and sulfide served as electron donors. NO3- was used as electron acceptor. In the presence of H2, also S2O32- could serve as electron acceptor. The isolate was a neutrophilic hyperthermophile that grew between 65 degrees C and 95 degrees C. It represents a novel genus among the Archaeoglobales that we name Ferroglobus. The type species is Ferroglobus placidus (DSM 10642).

exhibiting elongated MCC patches, there are elongated invaginations of the appropriate size and frequency. Using various approaches of immunoelectron microscopy, the MCC protein Sur7, as well as the eisosome marker Pil1, have been detected at these invaginations. Thus, we identify the MCC patch, which is a lateral membrane domain of specific composition and function, with a specific structure in the yeast plasma membrane -the furrow-like invagination.