IGEM:MIT/2007/Heavy Metals

Reviews

• Excellent Summary of Bacterial Metal Resistance (a must read)

1. Silver S and Phung le T. A bacterial view of the periodic table: genes and proteins for toxic inorganic ions. J Ind Microbiol Biotechnol. 2005 Dec;32(11-12):587-605. DOI:10.1007/s10295-005-0019-6 |

• A Good Overview on Pollution (though slightly back-dated): Quantitative assessment of worldwide contamination of air, water and soil by trace metals [1]
• A summary of Pollutants from the EPA [2]
• Review Papers on Bioremediation

2. Paul D, Pandey G, Pandey J, and Jain RK. Accessing microbial diversity for bioremediation and environmental restoration. Trends Biotechnol. 2005 Mar;23(3):135-42. DOI:10.1016/j.tibtech.2005.01.001 |
3. Valls M and de Lorenzo V. Exploiting the genetic and biochemical capacities of bacteria for the remediation of heavy metal pollution. FEMS Microbiol Rev. 2002 Nov;26(4):327-38. DOI:10.1111/j.1574-6976.2002.tb00618.x |
4. Bruins MR, Kapil S, and Oehme FW. Microbial resistance to metals in the environment. Ecotoxicol Environ Saf. 2000 Mar;45(3):198-207. DOI:10.1006/eesa.1999.1860 |

• Paul - discusses advantages/disadvantages/problems of bioremediation
• Bruins, Valls - discusses various kinds of bioremediation systems

Heavy Metal Binding Proteins/Peptides

5. Samuelson P, Wernérus H, Svedberg M, and Ståhl S. Staphylococcal surface display of metal-binding polyhistidyl peptides. Appl Environ Microbiol. 2000 Mar;66(3):1243-8. DOI:10.1128/AEM.66.3.1243-1248.2000 |
6. Pazirandeh M, Wells BM, and Ryan RL. Development of bacterium-based heavy metal biosorbents: enhanced uptake of cadmium and mercury by Escherichia coli expressing a metal binding motif. Appl Environ Microbiol. 1998 Oct;64(10):4068-72. DOI:10.1128/AEM.64.10.4068-4072.1998 |
7. Kotrba P, Dolecková L, de Lorenzo V, and Ruml T. Enhanced bioaccumulation of heavy metal ions by bacterial cells due to surface display of short metal binding peptides. Appl Environ Microbiol. 1999 Mar;65(3):1092-8. DOI:10.1128/AEM.65.3.1092-1098.1999 |
8. Mejáre M and Bülow L. Metal-binding proteins and peptides in bioremediation and phytoremediation of heavy metals. Trends Biotechnol. 2001 Feb;19(2):67-73. DOI:10.1016/s0167-7799(00)01534-1 |
9. Lu Y, Berry SM, and Pfister TD. Engineering novel metalloproteins: design of metal-binding sites into native protein scaffolds. Chem Rev. 2001 Oct;101(10):3047-80. DOI:10.1021/cr0000574 |

Cadmium

Summary

• Cd causes damage to cells primarily by the generation of reactive oxygen species (ROS), which causes single-strand DNA damage and disrupts the synthesis of nucleic acids and proteins. Cd is also an inhibitor of the DNA mismatch repair system…Results of this study confirmed that Cd toxicity caused profound changes in gene expression in which several stress response systems were induced simultaneously.
• known carcinogen
• Most recent(June06) paper on e.coli bioaccumulation of Cd

10. Deng X, Yi XE, and Liu G. Cadmium removal from aqueous solution by gene-modified Escherichia coli JM109. J Hazard Mater. 2007 Jan 10;139(2):340-4. DOI:10.1016/j.jhazmat.2006.06.043 |

Contamination Levels/Limits

• MCL(Maximum Containment Level): 5 ppb
• MCLG(Maximum Containment Level Goal): 5 ppb

11. Staessen JA, Lauwerys RR, Ide G, Roels HA, Vyncke G, and Amery A. Renal function and historical environmental cadmium pollution from zinc smelters. Lancet. 1994 Jun 18;343(8912):1523-7. DOI:10.1016/s0140-6736(94)92936-x |
12. Satarug S, Baker JR, Urbenjapol S, Haswell-Elkins M, Reilly PE, Williams DJ, and Moore MR. A global perspective on cadmium pollution and toxicity in non-occupationally exposed population. Toxicol Lett. 2003 Jan 31;137(1-2):65-83. DOI:10.1016/s0378-4274(02)00381-8 |

Cadmium Contamination Sites

13. Ishihara T, Kobayashi E, Okubo Y, Suwazono Y, Kido T, Nishijyo M, Nakagawa H, and Nogawa K. Association between cadmium concentration in rice and mortality in the Jinzu River basin, Japan. Toxicology. 2001 May 28;163(1):23-8. DOI:10.1016/s0300-483x(01)00367-5 |

Plachimada, India: [3]

• • statistics on Pb, Cd, Cr levels in well water surrounding a Coca-Cola plant (2006)
  • pictures too :)

Promoters

Pubmed: Plasmid pI258 (from S.aureus) cadmium resistance (cadA) gene, complete cds [4]

14. Brocklehurst KR, Megit SJ, and Morby AP. Characterisation of CadR from Pseudomonas aeruginosa: a Cd(II)-responsive MerR homologue. Biochem Biophys Res Commun. 2003 Aug 22;308(2):234-9. DOI:10.1016/s0006-291x(03)01366-4 |

• Brocklehurst - contains sequence for ZntR/CadR and PzntA/PcadA

• • Semmie's article on CadC linked with GFP [5]

Mercury

Contamination Levels/Limits

• MCL: 2 ppb
• MCLG: 2 ppb
• 20 ppb makes the fish mercury buildup significant

Polluted sites

• • Onondaga lake [6] [7] [8]
  • Salt Plains National Wildlife Refuge [9]

Detection (to assess our system)

• Gold Nanoparticles http://www.cah.ucf.edu/news/2005-Mercurynose.php

Promoter

15. Hamlett NV, Landale EC, Davis BH, and Summers AO. Roles of the Tn21 merT, merP, and merC gene products in mercury resistance and mercury binding. J Bacteriol. 1992 Oct;174(20):6377-85. DOI:10.1128/jb.174.20.6377-6385.1992 |
16. Park SJ, Wireman J, and Summers AO. Genetic analysis of the Tn21 mer operator-promoter. J Bacteriol. 1992 Apr;174(7):2160-71. DOI:10.1128/jb.174.7.2160-2171.1992 |
17. Condee CW and Summers AO. A mer-lux transcriptional fusion for real-time examination of in vivo gene expression kinetics and promoter response to altered superhelicity. J Bacteriol. 1992 Dec;174(24):8094-101. DOI:10.1128/jb.174.24.8094-8101.1992 |
18. Gambill BD and Summers AO. Versatile mercury-resistant cloning and expression vectors. Gene. 1985;39(2-3):293-7. DOI:10.1016/0378-1119(85)90326-9 |
19. Hansen LH and Sørensen SJ. Versatile biosensor vectors for detection and quantification of mercury. FEMS Microbiol Lett. 2000 Dec 1;193(1):123-7. DOI:10.1111/j.1574-6968.2000.tb09413.x |

• Condee - Contains sequence for merO/P region
• Hansen - Plasmid with Pmer, MerR, and reporter (lux, lac, or gfp) tested in e.coli

Sponge

• Accumulation of Hg ions in cell membrane [10]

Current Industry Filtration Techniques

Mercury: approved by EPA - Coagulation/Filtration; Granular Activated Carbon; Lime softening; Reverse osmosis.