||Bacteria Escherichia coli
||Mitchell JG, Pearson L, Bonazinga A, Dillon S, Khouri H, Paxinos R. Long lag times and high velocities in the motility of natural assemblages of marine bacteria. Appl Environ Microbiol. 1995 Mar61(3):877-82. p.877 left column top paragraphPubMed ID16534971
|| Macnab, R. M. 1987. Motility and chemotaxis, p. 732–759. In F. C. Neidhardt, J. L. Ingraham, K. B. Low, B. Magasanik, M. Schaechter, and H. E. Umbarger (ed.), Escherichia coli and Salmonella typhimurium: cellular and molecular biology, vol. 1. American Society for Microbiology, Washington, D.C.
||P.877 left column top paragraph: "Finding regions of increased nutrient concentration is important for maintaining motility as well as growth. Macnab (primary source) has pointed out the high genetic and biosynthetic expense of producing and maintaining the 60 or more proteins necessary for taxis in the single chemosensory system of Escherichia coli. The expense would appear to be even greater for some marine bacteria (Vibrio spp.) that possess two separate propulsion systems, one driven by protons and one driven by sodium ions (ref 2)."