• 1
    Gadd, G.M. (1992) Metals and microorganisms: a problem of definition. FEMS Microbiol. Letts. 100, 197204.
  • 2
    Hughes, M.N. and Poole, R.K. (1991) Metal speciation and microbial growth — the hard (and soft) facts. J. Gen. Microbiol. 137, 725734.
  • 3
    Ochiai, E. (1987) General Principles of Biochemistry of the Elements. Plenum Press, New York.
  • 4
    Rouch, D.A., Lee, B.T.O. and Morby, A.P. (1995) Understanding cellular responses to toxic agents: a mechanism-choice in bacterial metal resistance. J. Ind. Microbiol. 14, 132141.
  • 5
    Lutkenhaus, J.F. (1977) Role of a major outer membrane protein in Escherichia coli. J. Bacteriol. 131, 631637.
  • 6
    Nies, D.H. (1992) Resistance to cadmium, cobalt, zinc and nickel in microbes. Plasmid 27, 1728.
  • 7
    Kaur, P. and Rosen, B.P. (1992) Plasmid encoded resistance to arsenic and antimony. Plasmid 27, 2940.
  • 8
    Robinson, N.J., Gupta, A., Fordham-Skelton, A.P., Croy, R.R.D., Whitton, B.A. and Huckle, J.W. (1990) Prokaryotic metallothionein gene characterisation and expression: chromosome crawling by ligation mediated PCR. Proc. R. Soc. Lond. B 242, 241247.
  • 9
    Gadd, G.M. and Griffiths, A.J. (1978) Microorganisms and heavy metal toxicity. Microbiol. Ecol. 4, 303317.
  • 10
    Cooksey, D.A. (1994) Molecular mechanisms of copper resistance and accumulation in bacteria. FEMS Microbiol. Rev. 14, 381–386
  • 11
    Misra, T.K. (1992) Bacterial resistance to inorganic mercury salts and organomercurials. Plasmid 27, 416.
  • 12
    Brown, N.L., Rouch, D.A. and Lee, B.T.O. (1992) Copper resistance determinants in bacteria. Plasmid 27, 4151.
  • 13
    Cervantes, C. and Silver, S. (1992) Plasmid chromate resistance and chromate reduction. Plasmid 27, 6571.
  • 14
    Slawson, R.M., Van Dyke, M.I., Lee, H. and Trevors, J.T. (1992) Germanium and silver resistance, accumulation and toxicity in microorganisms. Plasmid 27, 7279.
  • 15
    Walter, E.G. and Taylor, D.E. (1992) Plasmid mediated resistance to tellurite: expressed and cryptic. Plasmid 27, 5664.
  • 16
    Von Burg, R and Greenwood, M.R. (1991) Mercury. In: Metals and Their Compounds in the Environment (Merian, E., Ed), pp. 1045–1088. VCH New York.
  • 17
    Silver, S., Endo, G. and Nakamura, K. (1994) Mercury in the environment and the laboratory. J. Jap. Soc. Water Environ. 17, 235243.
  • 18
    World Health Organisation. (1991) Environmental Health Criteria 118 Inorganic mercury (Friberg, L., Ed) World Health Organisation Geneva.
  • 19
    De Flora, S., Bennicelli, C. and Bagnasco, M. (1994) Genotoxicity of mercury compounds. A review. Mut. Res. 317, 5779.
  • 20
    Pan-Hou, H.S.K., Nishimoto, M. and Imura, N. (1981) Possible role of membrane proteins in mercury resistance of Enterobacter aerogenes Arch. Microbiol. 130, 9395.
  • 21
    Pan-Hou, H.S.K. and Imura, N. (1981) Role of hydrogen sulphide in mercury resistance determined by plasmid of Clostridium cochlearium T2. Arch. Microbiol. 129, 4952.
  • 22
    Baldi, F., Pepi, M. and Filippelli, M. (1993) Methylmercury resistance in Desulfovibrio desulfuricans strains in relation to methylmercury degradation. Appl. Environ. Microbiol. 59, 24792485.
  • 23
    Trevors, J.T. (1986) Mercury methylation by bacteria. J. Basic. Microbiol. 26, 499504.
  • 24
    Choi, S.C., Chase, T. and Bartha, R. (1994) Enzymatic catalysis of mercury methylation by Desulfovibrio desulfuricans. Appl. Environ. Microbiol. 60, 13421346.
  • 25
    Radford, A.J., Oliver, J., Kelly, W.J. and Reanney, D.C. (1981) Translocatable resistance to mercuric and phenylmercuric ions in soil bacteria. J. Bacteriol. 147, 11101112.
  • 26
    Kelly, W.J. and Reanney, D.C. (1984) Mercury resistance among soil bacteria: ecology and transferability of genes encoding resistance. Soil Biol. Biochem. 16, 18.
  • 27
    Jobling, M.G., Peters, S.E. and Ritchie, D.A. (1988a) Plasmid borne mercury resistance in aquatic bacteria. FEMS Microbiol. Letts. 49, 31–37.
  • 28
    Peters, S.E., Hobman, J.L., Strike, P. and Ritchie, D.A. (1991) Novel mercury resistance determinants carried by IncJ plasmids pMERPH and R391. Mol. Gen. Genet. 228, 12091217.
  • 29
    Grinsted, J., De La Cruz, F., and Schmitt, R. (1990) The Tn21 subgroup of bacterial transposable elements. Plasmid 24, 163189.
  • 30
    Brown, N.L. (1985) Bacterial resistance to mercury — reductio ad absurdum? Trends Biochem. Sci. 10, 400403.
  • 31
    Summers, A.O. (1986) Organisation, expression and evolution of genes for mercury resistance. Annu. Rev. Microbiol. 40, 607634.
  • 32
    Foster, T.J. (1987) The genetics and biochemistry of mercury resistance. CRC Crit. Rev. Microbiol. 15, 117140.
  • 33
    Brown, N.L., Camakaris, J., Lee, B.T.O., Williams, T., Morby, A.P., Parkhill, J. and Rouch, D.A. (1991) Bacterial resistances to mercury and copper. J. Cell. Biochem. 46, 106114.
  • 34
    Griffin, H.G., Foster, T.J., Silver, S. and Misra, T.K. (1987) Cloning and DNA sequence of the mercuric- and organomercurial-resistance determinant of plasmid pDU1358. Proc. Natl. Acad. Sci. USA 84, 31123116.
  • 35
    Laddaga, R.A., Chu, L., Misra, T.K. and Silver, S. (1987) Nucleotide sequence and expression of the mercurial-resistance operon from Staphylococcus aureus plasmid pI258. Proc. Natl. Acad. Sci. USA 84, 51065110.
  • 36
    Wang, Y., Moore, M., Levinson, H.S., Silver, S., Walsh, C. and Mahler, I. (1989) Nucleotide sequence of a chromosomal mercury resistance determinant from a Bacillus sp. with broad-spectrum mercury resistance. J. Bacteriol. 171, 8392.
  • 37
    Sedlmeier, R. and Altenbuchner, J. (1992) Cloning and DNA sequence analysis of the mercury resistance genes of Streptomyces lividans. Mol. Gen. Genet. 236, 7685.
  • 38
    Begley, T.P., Walts, A.E. and Walsh, C.T. (1986) Bacterial organomercurial lyase: overproduction, isolation and characterisation. Biochemistry 25, 71867192.
  • 39
    Kiyono, M., Omura, T., Fujimora, H. and Pan-Hou, H. (1995) Lack of involvement of merT and merP in methylmercury transport in mercury resistant Pseudomonas K-62. FEMS Microbiol. Letts. 128, 301306.
  • 40
    Summers, A.O. (1992) Untwist and shout: a heavy metal-responsive transcriptional regulator. J. Bacteriol. 174, 30973101.
  • 41
    Brünker, P., Rother, D., Sedlmeier, R., Klein, J., Mattes, R. and Altenbuchner, J. (1996) Regulation of the operon responsible for broad-spectrum mercury resistance in Streptomyces lividans 1326. Mol. Gen. Genet. 251, 307315.
  • 42
    Mukhopadhyay, D., Yu, H., Nucifora, G. and Misra, T.K. (1991) Purification and characterisation of MerD. J. Biol. Chem. 266, 1853818542.
  • 43
    Smith, D.H. (1967) R factors mediate resistance to mercury, nickel and cobalt. Science 156, 11141116.
  • 44
    Bennett, P.M. (1995) The spread of drug resistance. In: Population Genetics of Bacteria. (Baumberg, S., Young, J.P.W., Wellington, E.M.H. and Saunders, J.R., Eds), pp. 317–344. Cambridge University Press.
  • 45
    Ka, J.O., Holben, W.E. and Tiedje, J.M. (1994) Genetic and phenotypic diversity of 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacteria isolated from 2,4-D treated field soils. Appl. Environ. Microbiol. 60, 11061115.
  • 46
    Khesin, R.B. and Karasyova, E.V. (1984) Mercury-resistant plasmids in bacteria from a mercury and antimony deposit area. Mol. Gen. Genet. 197, 280285.
  • 47
    Olson, B.H., Lester, J.N., Cayless, S.M. and Ford, S.J. (1989) Distribution of mercury resistance determinants in bacterial communities of river sediments. Water Res. 23, 12091217.
  • 48
    Belliveau, B.H., Starodub, M.E. and Trevors, J.T. (1991) Occurrence of antibiotic and metal resistance plasmids in Bacillus strains isolated from marine sediment. J. Can. Microbiol. 37, 513520.
  • 49
    Rochelle, P.A., Wetherbee, M.K. and Olson, B.H. (1991) Distribution of DNA sequences encoding narrow- and broad-spectrum mercury resistance. Appl. Environ. Microbiol. 57, 15811589.
  • 50
    Mirgain, I., Hagnere, C., Green, G.A., Harf, C. and Monteil, H. (1992) Synthetic oligonucleotide probes for detection of mercury-resistance genes in environmental freshwater microbial communities in response to pollutants. World J. Microbiol. Biotechnol. 6, 3038.
  • 51
    Prabu, S.K. and Mahadevan, A. (1992) Hybridisation of transposon Tn501 for detection of mercury resistance sequences in a marine environment. Res. Microbiol. 143, 341345.
  • 52
    Osborn, A.M., Bruce, K.D., Strike, P. and Ritchie, D.A. (1993) Polymerase chain reaction-restriction fragment length polymorphism analysis shows divergence among mer determinants from Gram-negative soil bacteria indistinguishable by DNA–DNA hybridisation. Appl. Environ. Microbiol. 59, 40244030.
  • 53
    Schottel, J., Mandal, A., Clark, D., Silver, S. and Hedges, R.W. (1974) Volatilisation of mercury and organomercurials determined by inducible R-factor systems in enteric bacteria. Nature 251, 335337.
  • 54
    Nakahara, H., Ishikawa, T., Sarai, Y., Kondo, I. and Mitsuhashi, S. (1977) Frequency of heavy-metal resistance in bacteria from inpatients in Japan. Nature 266, 165167.
  • 55
    Gilbert, M.P. and Summers, A.O. (1988) The distribution and divergence of DNA sequences related to the Tn21 and Tn501 mer operons. Plasmid 20, 127136.
  • 56
    Steingrube, V.A., Wallace, R.J., Steele, L.C. and Pang, Y. (1991) Mercuric reductase activity and evidence of broad-spectrum mercury resistance among clinical isolates of rapidly growing Mycobacteria. Antimicrob. Agents Chemother. 35, 819823.
  • 57
    Kholodii, G.Y., Gorlenko, Z.M., Lomovskaya, O.L., Mindlin, S.Z., Yurieva, O.V. and Nikiforov, V.G. (1993a) Molecular characterisation of an aberrant mercury resistance transposable element from an environmental Acinetobacter strain. Plasmid 30, 303–308.
  • 58
    Osborn, A.M., Bruce, K.D., Strike, P. and Ritchie, D.A. (1995) Sequence conservation between regulatory mercury resistance genes in bacteria from mercury polluted and pristine environments. Syst. Appl. Microbiol. 18, 16.
  • 59
    Radosevich, M. and Klein, D.A. (1993) Bacterial enumeration and mercury volatilization in deep subsurface sediment samples. Bull. Environ. Contam. Toxicol. 51, 226233.
  • 60
    Osborn, A.M., Bruce, K.D., Ritchie, D.A. and Strike, P. (1996) The mercury resistance operon of the IncJ plasmid pMERPH exhibits structural and regulatory divergence from other Gram-negative mer operons. Microbiology 142, 337345.
  • 61
    Hamlett, N.V., Landale, E.C., Davis, B.H. and Summers, A.O. (1992) Roles of the Tn21 merT, merP and merC gene products in mercury resistance and mercury binding. J. Bacteriol. 174, 63776385.
  • 62
    Kusano, T., Ji, G., Inoue, C. and Silver, S. (1990) Constitutive synthesis of a transport function encoded by the Thiobacillus ferrooxidans merC gene cloned in Escherichia coli. J. Bacteriol. 172, 26882692.
  • 63
    Inoue, C., Kusano, T. and Silver, S. (1996) Mercuric ion uptake by Escherichia coli cells producing Thiobacillus ferrooxidans MerC. Biosci. Biotech. Biochem. 60, 12891292.
  • 64
    Reniero, D., Galli, E. and Barbieri, P. (1995) Cloning and comparison of mercury- and organomercurial-resistance determinants from a Pseudomonas stutzeri plasmid. Gene 166, 7782.
  • 65
    Inoue, C., Sugawara, K. and Kusano, T. (1991) The merR regulatory gene in Thiobacillus ferrooxidans is spaced apart from the mer structural genes. Mol. Microbiol. 5, 27072718.
  • 66
    Barkay, T., Fouts, D.L. and Olson, B.H. (1985) Preparation of a DNA gene probe for detection of mercury resistance genes in Gram-negative bacterial communities. Appl. Environ. Microbiol. 49, 686692.
  • 67
    Barkay, T., Liebert, C. and Gillmann, M. (1989a) Environmental significance of the potential for mer (Tn21)-mediated reduction of Hg2+ to Hg0 in natural waters. Appl. Environ. Microbiol. 55, 1196–1202.
  • 68
    Barkay, T., Gillmann, M. and Liebert, C. (1990) Genes encoding mercuric reductase from selected Gram-negative bacteria have a low degree of homology with merA of transposon Tn501. Appl. Environ. Microbiol. 56, 16951701.
  • 69
    Amann, R.I., Ludwig, W. and Schleifer, K.H. (1995) Phylogenetic identification and in situ detection of individual microbial cells without cultivation. Microbiol. Rev. 59, 143169.
  • 70
    Barkay, T., Liebert, C. and Gillmann, M. (1989b) Hybridisation of DNA probes with whole community genome for detection of genes that encode microbial responses to pollutants: mer genes and Hg2+ resistance. Appl. Environ. Microbiol. 55, 1574–1577.
  • 71
    Jobling, M.G., Peters, S.E. and Ritchie, D.A. (1988b) Restriction pattern and polypeptide homology among plasmid-borne mercury resistance determinants. Plasmid 20, 106–112.
  • 72
    Peters, S.E. (1988) Mercury Resistance Plasmids in Aquatic Bacteria. Ph.D. Thesis, University of Liverpool, UK.
  • 73
    Hobman, J.L., Kholodii, G., Nikiforov, V., Ritchie, D.A., Strike, P. and Yurieva, O. (1994) The nucleotide sequence of the mer operon of pMER327/419 and transposon ends of pMER327/419, 330 and 05. Gene 146, 7378.
  • 74
    Pearson, A.J. (1996) Mercury Resistance Transposons in Environmental Bacteria. Ph.D. Thesis, University of Liverpool, UK.
  • 75
    Nakamura, K. and Silver, S. (1994) Molecular analysis of mercury resistant Bacillus isolates from sediment of Minimata bay, Japan. Appl. Environ. Microbiol. 60, 45964599.
  • 76
    Bruce, K.D., Osborn, A.M., Pearson, A.J., Strike, P. and Ritchie, D.A. (1995) Genetic diversity within mer genes directly amplified from communities of non-cultivated soil bacteria. Mol. Ecol. 4, 605612.
  • 77
    Kholodii, G.Y., Yurieva, O.V., Lomovskaya, O.L., Gorlenko, Z.M., Mindlin, S.Z. and Nikiforov, V.G. (1993b) Tn5053, a mercury resistance transposon with integron's ends. J. Mol. Biol. 230, 1103–1107.
  • 78
    Suzuki, M.T. and Giovannoni, S.J. (1996) Bias caused by template annealing in the amplification of mixtures of 16S rRNA genes by PCR. Appl. Environ. Microbiol. 62, 625630.
  • 79
    Pearson, A.J., Bruce, K.D., Osborn, A.M., Ritchie, D.A. and Strike, P. (1996) Distribution of Class II transposase and resolvase genes in soil bacteria and their association with mer genes. Appl. Environ. Microbiol. 62, 29612965.
  • 80
    Holt, R.J., Strike, P. and Bruce, K.D. (1996) Phylognetic analysis of tnpR genes in mercury resistant soil bacteria: the relationship between DNA sequencing and RFLP typing approaches. FEMS Microbiol. Lett. 144, 95102.
  • 81
    Silver, S. and Walderhaug, M. (1992) Gene regulation of plasmid- and chromosome- determined inorganic ion transport in bacteria. Microbiol. Rev. 56, 195228.
  • 82
    Christie, G.E., White, T.J. and Goodwin, T.S. (1994) A merR homologue at 74 minutes on the Escherichia coli genome. Gene 146, 131132.
  • 83
    Fleischmann, R.D., Adams, M.D., White, O., Clayton, R.A., Kirkness, E.F., Kerlavage, A.R., Bult, C.J., Tomb, J-F., Dougherty, B.A., Merrick, J.M., McKenny, K., Sutton, G., FitzHugh, W., Fields, C., Gocayne, J.D., Scott, J., Shirley, R., Liu, L-I., Glodek, A., Kelley, J.M., Weidman, J.F., Phillips, C.A., Spriggs, T., Hedblom, E., Cotton, M.D., Utterback, T.R., Hanna, M.C., Nguyen, D.T., Saudek, D.M., Brandon, R.C., Fine, L.D., Fritchman, J.L., Fuhrmann, J.L., Geoghagen, N.S.M., Gnehm, C.L., McDonald, L.A., Small, K.V., Fraser, C.M., Smith, H.O. and Ventner, J.C. (1995) Whole-genome random sequencing and assembly of Haemophilus influenzae Rd. Science 269, 496512.
  • 84
    Amábile-Cuevas, C.F. and Demple, B. (1991) Molecular characterisation of the soxRS genes of Escherichia coli: two genes encoding a superoxide stress regulon. Nucl. Acids Res. 19, 44794484.
  • 85
    Morby, A.P., Hobman, J.L. and Brown, N.L. (1995) The role of cysteine residues in the transport of mercuric ions by the Tn501 MerT and MerP mercury-resistance proteins. Mol. Microbiol. 17, 11531162.
  • 86
    Barrineau, P., Gilbert, P., Jackson, W.J., Jones, C.S., Summers, A.O. and Wisdom, S. (1983) The DNA sequence of the mercury resistance operon of the IncFII plasmid NR1. J. Mol. Appl. Genet. 2, 601619.
  • 87
    Nucifora, G., Chu, L., Silver, S. and Misra, T.K. (1989) Mercury operon regulation by the merR gene of the organomercurial resistance system of pDU1358. J. Bacteriol. 171, 42414247.
  • 88
    Bogdanova, E.S., Mindlin, S.Z., Pakrová, E., Kocur, M. and Rouch, D.A. (1992) Mercuric reductase in environmental Gram-positive bacteria sensitive to mercury. FEMS Microbiol. Lett. 97, 95100.
  • 89
    De Boorder, H., Panov, B.S., Westerhof, A.B. and Korcemagin, V.A. (1995) Tectonic setting, deep faults and mercury mineralization at Almadén, Spain, and Nikitovka, Ukraine: affinities and contrasts. Trans. Instn. Min. Metall. (Sect. B: Appl. Earth Sci.), 104, B68B79.
  • 90
    Schopf, J.W. (1993) Microfossils of the early archaean apex chert: new evidence of the antiquity of life. Science 260, 640646.
  • 91
    Helmann, J.D., Wang, Y., Mahler, I. and Walsh, C.T. (1989) Homologous metalloregulatory proteins from both Gram-positive and Gram-negative bacteria control transcription of mercury resistance operons. J. Bacteriol. 171, 222229.
  • 92
    Bogdanova, E.S., Mindlin, S.Z., Kalyyaeva, E.S. and Nikiforov, V.G. (1988) The diversity of mercury reductases among mercury resistant bacteria. FEBS Lett. 234, 280282.
  • 93
    Coetzee, J.N., Datta, N. and Hedges, R.W. (1972) R factors from Proteus rettgeri J. Gen. Microbiol. 72, 543552.
  • 94
    Brown, N.L., Ford, S.J., Pridmore, R.D. and Fritzinger, D.C. (1983) Nucleotide sequence of a gene from the Pseudomonas transposon Tn501 encoding mercuric reductase. Biochemistry 22, 40894095.
  • 95
    Ahmed, M., Lyass, L., Markham, P.N., Taylor, S.S. Vasquez-Laslop, N. and Neyfakh, A.A. (1995) Two highly similar multidrug transporters of Bacillus subtilis whose expression is differentially regulated. J. Bacteriol. 177, 39043910.
  • 96
    Nakano, Y. and Kimura, K. (1991) Purification and characterisation of a repressor for the Bacillus cereus glnRA operon. J. Biochem. 109, 223228.
  • 97
    Brown, N.L. and Goddette, D. (1984) The evolution of mercuric reductase, a redox transfer model for mercuric ion detoxification in bacteria. In: Flavins and Flavoproteins. (Bray, R.C., Engel, P.C. and Mayhew, S.G., Eds.) p165. Walter de Gruyter, Berlin.
  • 98
    Tanaka, M., Yamamoto, T. and Sawai, T. (1983) Evolution of complex resistance transposons from an ancestral mercury transposon. J. Bacteriol. 153, 14321438.
  • 99
    Osbourn, S.E.V., Turner, A.K. and Grinsted, J. (1995) Nucleotide sequence within Tn3926 confirms this as a Tn21-like transposable element and provides evidence for the origin of the mer operon carried by pKLH2. Plasmid 33, 6569.
  • 100
    Brown, N.L., Misra, T.K., Winnie, J.N., Schmidt, A., Seiff, M. and Silver, S. (1986) The nucleotide sequence of the mercuric resistance operons of R100 and transposon Tn501: further evidence for mer genes which enhance the activity of the mercuric ion detoxification system. Mol. Gen. Genet. 220, 143151.
  • 101
    Clennel A.M., Johnstone, B. and Rawlings, D.E. (1995) Structure and function of Tn5467, a Tn21-like transposon located on the Thiobacillus ferrooxidans broad-host-range plasmid pTF-FC2. Appl. Env. Microbiol. 61, 42234229.
  • 102
    Siemieniak, D.R., Slighton, J.L. and Chung, S.T. (1990) Nucleotide sequence of Streptomyces fradiae transposable element Tn4556, a class II transposon related to Tn3. Gene 86, 19.
  • 103
    Grinsted, J., and Brown, N.L. (1984) A Tn21 terminal sequence within Tn501: complementation of tnpA gene function and transposon evolution. Mol. Gen. Genet. 197, 497501.
  • 104
    Kholodii, G.Y., Mindlin, S.Z., Bass, I.A., Yurieva, O.V., Minakhina, S.V. and Nikiforov, V.G. (1995) Four genes, two ends, and a res region are involved in transposition of Tn5053: a paradigm for a novel family of transposons carrying either a mer operon or an integron. Mol. Microbiol. 17, 11891200.
  • 105
    Inoue, C. Sugawara, K. and Kusano, T. (1990) Thiobacillus ferrooxidans mer operon: sequence analysis of the promoter and adjacent genes. Gene 96, 115120.
  • 106
    Eichenseer, C. and Altenbuchner, J. (1994) The very large amplifiable element AUD2 from Streptomyces lividans 66 has insertion sequence-like repeats at its ends. J. Bacteriol. 176, 71077112.
  • 107
    Woese, C.R., Kandler, O. and Wheelis, M.L. (1990) Towards a natural system of organisms: proposal for the domains Archaea, Bacteria and Eucarya. Proc. Natl. Acad. Sci. USA 86, 93559359.
  • 108
    Lane, D.J., Pace, B., Olsen, G.J., Stahl, D.A., Sogin, M.L. and Pace, N.R. (1985) Rapid determination of 16S ribosomal RNA sequences for phylogenetic analyses. Proc. Natl. Acad. Sci. USA 82, 69556959.
  • 109
    Edwards, U., Rogall, T., Blöcker, H., Emde, M. and Böttger, E.C. (1989) Isolation and direct complete nucleotide determination of entire genes. Characterisation of a gene coding for 16S ribosomal RNA. Nucl. Acids Res. 17, 78437853.
  • 110
    Larsen, N., Olsen, G.J., Maidek, B.L., McCaughey, M.J., Overbeek, R., Macke, T.J., Marsh, T.L. and Woese, C.R. (1993) The ribosomal database project. Nucl. Acids Res. 21, 30213023.
  • 111
    Giovannoni, S.J., Britschgi, T.B., Moyer, C.L. and Field, K.G. (1990) Genetic diversity in Sargasso Sea bacterioplankton. Nature 345, 6063.
  • 112
    Liesack, W. and Stackebrandt, E. (1992) Occurrence of novel groups of the domain Bacteria as revealed by analysis of genetic material isolated from an Australian terrestrial environment. J. Bacteriol. 174, 50725078.
  • 113
    Hales, B.A., Edwards, C., Ritchie, D.A., Hall, G., Pickup, R.W. and Saunders, J.R. (1996) Isolation and identification of Methanogen-specific DNA from blanket bog peat by PCR amplification and sequence analysis. Appl. Environ. Microbiol. 62, 668675.
  • 114
    Rochelle, P.A., Cragg, B.A., Fry, J.C., Parkes, R.J. and Weightman, A.J. (1994) Effect of sample handling on estimation of bacterial diversity in marine sediments by 16S rRNA gene sequence analysis. FEMS Microbiol. Ecol. 15, 215226.
  • 115
    Lloyd, A.T. and Sharp, P.M. (1993) Evolution of the recA gene and the molecular phylogeny of bacteria. J. Mol. Evol. 37, 399407.
  • 116
    Gupta, R.S. and Golding, B.G. (1993) Evolution of HSP70 gene and its implications regarding relationships between Archaebacteria, Eubacteria and Eukaryotes. J. Mol. Evol. 37, 573582.
  • 117
    Tiboni, O., Cammarano, P. and Sanangelantoni, A.M. (1993) Cloning and sequencing of the gene encoding glutamine synthetase I from the archaeum Pyrococcus woesei: anomalous phylogenies inferred from analysis of archaeal and bacterial glutamine synthetase I sequences. J. Bacteriol. 175, 29612969.
  • 118
    Arber, W. (1993) Evolution of prokaryotic genomes. Gene 135, 4956.
  • 119
    Maynard Smith, J. (1992) Analyzing the mosaic structure of genes. J. Mol. Evol. 34, 126129.
  • 120
    Spratt, B.G., Bowler, L.D., Zhang, Q.Y., Zhou, J. and Maynard Smith, J. (1992) Role of interspecies transfer of chromosomal genes in the evolution of penicillin resistance in pathogenic and commensal Neisseria species. J. Mol. Evol. 34, 115125.
  • 121
    Eberhard, W.G. (1989) Why do bacterial plasmids carry some genes and not others Plasmid 21, 167174.
  • 122
    Arber, W. (1991) Elements in microbial evolution. J. Mol. Evol. 33, 412.
  • 123
    Barkay, T. and Olson, B.H. (1986) Phenotypic and genotypic adaptation of aerobic heterotrophic sediment bacterial communities to mercury stress. Appl. Environ. Microbiol. 52, 403406.
  • 124
    Bale, M.J., Fry, J.C. and Day, M.J. (1988) Transfer and occurrence of large mercury resistance plasmids in river epilithon. Appl. Environ. Microbiol. 54, 972978.
  • 125
    Rochelle, P.A., Fry, J.C. and Day, M.J. (1989) Factors affecting conjugal transfer of plasmids encoding mercury resistance from pure cultures and mixed natural suspensions of epilithic bacteria. J. Gen. Microbiol. 135, 409424.
  • 126
    Perkins, C.D., Davidson, A.M., Day, M.J. and Fry, J.C. (1994) Retrotransfer kinetics of R300B by pQKH6, a conjugative plasmid from river epilithon. FEMS Microbiol. Ecol. 15, 3344.
  • 127
    Lilley, A.K., Fry, J.C., Day, M.J. and Bailey, M.J. (1994) In situ transfer of an exogenously isolated plasmid between Pseudomonas spp. in sugar beet rhizosphere. Microbiology 140, 2733.
  • 128
    Tsai, Y.L. and Olson, B.H. (1991) Rapid method for direct extraction of DNA from soils and sediments. Appl. Environ. Microbiol. 57, 10701074.
  • 129
    Bruce, K.D., Hiorns, W.D., Hobman, J.L., Osborn, A.M., Strike, P. and Ritchie, D.A. (1992) Amplification of DNA from native populations of soil bacteria by using the polymerase chain reaction. Appl. Environ. Microbiol. 58, 34133416.
  • 130
    Kapitsa, A.P., Ridley, J.K., Robin, G.D., Siegert, M.J. and Zotikov, I.A. (1996) A large deep freshwater lake beneath the ice of central east Antarctica. Nature 381, 684686.
  • 131
    Olson, B.H., Barkay, T. and Colwell, R.R. (1979) Role of plasmids in mercury transformation by bacteria isolated from the aquatic environment. Appl. Environ. Microbiol. 38, 478485.
  • 132
    Dressler, C., Kues, U., Nies, D.H. and Friedrich, B. (1991) Determinants encoding resistance to several heavy-metals in newly isolated copper-resistant bacteria. Appl. Environ. Microbiol. 57, 30793085.
  • 133
    Diels, L., Sadouk, A. and Mergeay, M. (1989) Large plasmids governing multiple resistances to heavy metals — A genetic approach. Toxicol. Environ. Chem. 23, 7989.
  • 134
    Ray, S., Gachhui, R., Chaudhuri, J. and Mandal, A. (1989) Mercury resistance in nitrogen-fixing soil bacteria. J. Gen. Appl. Microbiol. 35, 8394.
  • 135
    Mahler, I., Levinson, H.S., Wang, Y. and Halvorson, H.O. (1986) Cadmium- and mercury-resistant Bacillus strains from a salt marsh and from Boston Harbour. Appl. Environ. Microbiol. 52, 12931298.
  • 136
    Trevors, J.T. (1987) Mercury-resistance and mercuric reductase activity in Chromobacterium, Erwina and Bacillus species. Bull. Environ. Contam. Toxicol. 38, 10701075.
  • 137
    Nakamura, K., Sakamoto, M., Uchiyama, H. and Yagi, O (1990) Organomercurial-volatilising bacteria in the mercury polluted sediment of Minimata bay. Jpn. Appl. Environ. Microbiol. 56, 304–305.
  • 138
    Izaki, K. (1981) Enzymatic reduction of mercurous and mercuric ions in Bacillus cereus Can. J. Microbiol. 27, 192197.
  • 139
    Pahan, K., Ray, S., Gachhui, R., Chauduri, J. and Mandal, A. (1990) Effect of thiol compounds and flavins on mercury and organomercurial degrading enzymes in mercury resistant aquatic bacteria. Bull. Environ. Contam. Toxicol. 44, 216223.
  • 140
    Avilacampos, M.J., Decavalho, M.A.R., Damasceno, C.A.V., Chartonesouza, E., Cisalpino, E.O. (1991) Population stability in species of the Bacteroides fragilis group, under mercuric-chloride action. Rev. Microbiol. 22, 9396.
  • 141
    Rudrik, J.T., Bawdon, R.E. and Guss, S.P. (1985) Determination of mercury and organomercurial resistance in obligate anaerobic bacteria. Can. J. Microbiol. 31, 276281.
  • 142
    Katsu, K., Inoue, M. and Mitsuhashi, S. (1982) Transposition of the carbenicillin-hydrolysing β-lactamase gene. J. Bacteriol. 150, 483489.
  • 143
    Griffin, H.G., Foster, T.J., Falkiner, F.R., Carr, M.E. and Coleman, D.C. (1985) Molecular analysis of multiple-resistance plasmids transferred from Gram-negative bacteria isolated in a urological unit. Antimicrob. Agents Chemother. 28, 413418.
  • 144
    Zscheck, K.K. and Murray, B.E. (1990) Evidence for a Staphylococcal-like mercury resistance gene in Enterococcus faecalis. Antimicrob. Agents Chemother. 34, 12871289.
  • 145
    Nascimento, A.M.A., Deazevedo, M.O., Astolfi, S. and Chartonesouza, E. (1992) Cloning of the mercuric ion-resistance operon of pBH100 into Escherichia coli 5K using pAT153 as vector. Rev. Microbiol. 23, 217220.
  • 146
    Kono, M., O'Hara, K., Arai, Y., Fukuda, H., Asakawa, M. and Nakahara, H. (1985) Inactivation and sedimentation of mercury from organomercurials by Klebsiella pneumoniae. FEMS Microbiol. Lett. 28, 213217.
  • 147
    Kawasaki, H., Yahara, H. and Tonomura, K. (1981) Isolation and characterisation of plasmid pUO1 mediating dehalogenation of haloacetate and mercury resistance in Moraxella sp. Agric. Biol. Chem. 45, 14771481.
  • 148
    Meissner, P.S. and Falkinham, J.O. (1984) Plasmid-encoded mercuric reductase in Mycobacterium scrofulaceum. J. Bacteriol. 157, 669-672.
  • 149
    Stanisich, V.A., Bennett, P.M. and Richmond, M.H. (1977) Characterisation of a translocation unit encoding resistance to mercuric ions that occurs on a nonconjugative plasmid in Pseudomonas aeruginosa. J. Bacteriol. 129, 12271233.
  • 150
    Johnson, J., Waren, R.L. and Branstrom, A.A. (1991) Effects of FP2 and a mercury resistance plasmid from Pseudomonas aeruginosa PA103 on exoenzyme production. J. Clin. Microbiol. 29, 940944.
  • 151
    Levesque, R.C. and Jacoby, G.A. (1988) Molecular structure and interrelationships of multiresistance β-lactamase transposons. Plasmid 19, 2129.
  • 152
    Sabaté, J., Villaneuva, A. and Prieto, M.J. (1994) Isolation and characterization of a mercury-resistant broad-host-range plasmid from Pseudomonas cepacia. FEMS Microbiol. Lett. 119, 345350.
  • 153
    Harder, P.A. and Kunz, D.A. (1986) Characterisation of the OCT plasmid encoding alkane oxidation and mercury resistance in Pseudomonas putida. J. Bacteriol. 165, 650653.
  • 154
    Kunze, I., Loechel, D. and Gunther, E. (1988) Broad-spectrum and narrow-spectrum mercury resistance encoded by different plasmids of a Pseudomonas putida strain. FEMS Microbiol. Lett. 50, 177181.
  • 155
    Barbieri, P., Galassi, G. and Galli, E. (1989) Plasmid encoded mercury resistance in a Pseudomonas stutzeri strain that degrades o-xylene. FEMS Microbiol. Ecol. 62, 375384.
  • 156
    Meyer, J.F., Nies, B.A., Kratz, J. and Wiedemann, B. (1985) Evolution of Tn21-related transposons: Isolation of Tn2425, which harbors IS161. J. Gen. Microbiol. 131, 11231130.
  • 157
    Dabrock, B., Kesseler, M., Averhoff, B. and Gottschalk, G. (1994) Identification and characterisation of a transmissible linear plasmid from Rhodococcus-erythropolis BD2 that encodes isopropylbenzene and trichloroethane catabolism. Appl. Environ. Microbiol. 60, 853860.
  • 158
    Kratz, J., Schmidt, F. and Wiedemann, B. (1983) Characterisation of Tn2411 and Tn2410, two transposons derived from R plasmid R1767 and related to Tn2603 and Tn21. J. Bacteriol. 155, 13331342.
  • 159
    Nisen, P.D., Kopecko, D.J., Chou, J. and Cohen, S.N. (1977) Site-specific DNA deletions occurring adjacent to the termini of a transposable ampicillin resistance element (Tn3). J. Mol. Biol. 117, 975998.
  • 160
    Meyer, J.F., Nies, B.L. and Wiedemann, B. (1983) Amikacin resistance mediated by multiresistance transposon Tn2424. J. Bacteriol. 155, 755760.
  • 161
    Novick, R.P. and Roth, C. (1968) Plasmid-linked resistance to inorganic salts in Staphylococcus aureus. J. Bacteriol. 95, 13351342.
  • 162
    Weiss, A.A., Murphy, S.D. and Silver, S. (1977) Mercury and organomercurial resistances determined by plasmids in Staphylococcus aureus. J. Bacteriol. 132, 197208.
  • 163
    Nakahara, H., Schottel, J.L., Yamada, T., Miyakawa, Y., Asakawa, M., Harville, J. and Silver, S. (1985) Mercuric reductase enzymes from Streptomyces species and Group B Streptococcus. J. Gen. Microbiol. 131, 10531059.
  • 164
    Olson, G.J., Porter, F.D., Rubinstein, J. and Silver, S. (1982) Mercuric reductase enzyme from a mercury-volatilizing strain of Thiobacillus ferrooxidans. J. Bacteriol. 151, 12301236.
  • 165
    Shiratori, T., Inoue, C., Sugawara, K., Kusano, T. and Kitigawa, Y. (1989) Cloning and expression of Thiobacillus ferrooxidans mercury ion resistance genes in Escherichia coli. J. Bacteriol. 171, 34583464.
  • 166
    Vidon, D.J.M., Lett, M.C. and Delmas, C.L. (1981) Mercury resistance in Yersinia enterocolitica. Ann. Microbiol. 132, 197231.
  • 167
    Lett, M.J., Bennett, P.M. and Vidon, D.J.M. (1985) Characterisation of Tn3926, a new mercury-resistance transposon from Yersinia enterocolitica. Gene 40, 7991.
  • 168
    Misra, T.K., Brown, N.L., Fritzinger, D.C., Pridmore, R.D., Barnes, W.M., Haberstroh, L. and Silver, S. (1984) Mercuric ion-resistance operons of plasmid R100 and transposon Tn501: the beginning of the operon including the regulatory region and the first two structural genes. Proc. Natl. Acad. Sci. USA 81, 59755979.
  • 169
    Inoue, C., Sugawara, K., Shiratori, T., Kusano, T. and Kitigawa, Y. (1989) Nucleotide sequence of the Thiobacillus ferrooxidans chromosomal gene encoding mercuric reductase. Gene 84, 4754.
  • 170
    Rawlings, D.E., Dorrington, R.D., Rohrer, J. and Clennel, A.M. (1993) FEMS Microbiol. Rev. 11, 38.
  • 171
    Devereux, J., Haeberli, P. and Smithies, O. (1984) A comprehensive set of sequence analysis programs for the VAX. Nucl. Acids Res. 12, 387395.
  • 172
    Felsenstein, J. (1993) PHYLIP (Phylogeny Inference Package) version 3.5C Department of Genetics, University of Washington, Seattle.
  • 173
    Felsenstein, J. (1985) Confidence limits on phylogenies: an approach using the bootstrap. Evolution 39, 783791.