Archaellum Moves Archaea with Distinction

Abstract

Cell motility in pure cultures of halophilic archaea was first observed almost a century ago and, in methanogens, at least as long ago as 1951, when Methanococcus vannielii was first isolated. Although M. vannielii was reported as being motile, no flagella were observed until nearly three decades later. Other researchers from that era reported seeing fimbriae (pili) or flagella on a variety of different archaea, including methanogens, halophiles, and Sulfolobus. However, during that period the members of the archaea were still considered bacteria, predating the groundbreaking realignment of the tree of life into the three domains of Archaea, Bacteria, and Eukarya by Carl Woese.