Skip to main content
Top
Published in: Journal of Nanoparticle Research 12/2011

01-12-2011 | Research Paper

Antibacterial activities of magnesium oxide (MgO) nanoparticles against foodborne pathogens

Authors: Tony Jin, Yiping He

Published in: Journal of Nanoparticle Research | Issue 12/2011

Log in

Activate our intelligent search to find suitable subject content or patents.

search-config
loading …

Abstract

The antibacterial activities of magnesium oxide nanoparticles (MgO NP) alone or in combination with other antimicrobials (nisin and ZnO NP) against Escherichia coli O157:H7 and Salmonella Stanley were investigated. The results show that MgO NP have strong bactericidal activity against the pathogens, achieving more than 7 log reductions in bacterial counts. The antibacterial activity of MgO NP increased as the concentrations of MgO increased. A synergistic effect of MgO in combination with nisin was observed as well. However, the addition of ZnO NP to MgO NP did not enhance the antibacterial activity of MgO against both pathogens. Scanning electron microscopy was used to characterize the morphological changes of E. coli O157:H7 before and after antimicrobial treatments. It was revealed that MgO NP treatments distort and damage the cell membrane, resulting in a leakage of intracellular contents and eventually the death of bacterial cells. These results suggest that MgO NP alone or in combination with nisin could potentially be used as an effective antibacterial agent to enhance food safety.

Dont have a licence yet? Then find out more about our products and how to get one now:

Springer Professional "Wirtschaft+Technik"

Online-Abonnement

Mit Springer Professional "Wirtschaft+Technik" erhalten Sie Zugriff auf:

  • über 102.000 Bücher
  • über 537 Zeitschriften

aus folgenden Fachgebieten:

  • Automobil + Motoren
  • Bauwesen + Immobilien
  • Business IT + Informatik
  • Elektrotechnik + Elektronik
  • Energie + Nachhaltigkeit
  • Finance + Banking
  • Management + Führung
  • Marketing + Vertrieb
  • Maschinenbau + Werkstoffe
  • Versicherung + Risiko

Jetzt Wissensvorsprung sichern!

Springer Professional "Technik"

Online-Abonnement

Mit Springer Professional "Technik" erhalten Sie Zugriff auf:

  • über 67.000 Bücher
  • über 390 Zeitschriften

aus folgenden Fachgebieten:

  • Automobil + Motoren
  • Bauwesen + Immobilien
  • Business IT + Informatik
  • Elektrotechnik + Elektronik
  • Energie + Nachhaltigkeit
  • Maschinenbau + Werkstoffe




 

Jetzt Wissensvorsprung sichern!

Literature
go back to reference Al-Holy M, Al-Qadiri H, Lin M, Rasco B (2006) Inhibition of Listeria innocua in hummus by a combination of nisin and citric acid. J Food Protect 69(6):1322–1327 Al-Holy M, Al-Qadiri H, Lin M, Rasco B (2006) Inhibition of Listeria innocua in hummus by a combination of nisin and citric acid. J Food Protect 69(6):1322–1327
go back to reference Boziaris IS, Adams MR (2001) Temperature shock, injury and transient sensitivity to nisin in Gram-negatives. J Appl Microbiol 91:715–724CrossRef Boziaris IS, Adams MR (2001) Temperature shock, injury and transient sensitivity to nisin in Gram-negatives. J Appl Microbiol 91:715–724CrossRef
go back to reference Chandrapati S, O’Sullivan DJ (1998) Procedure for quantifiable assessment of nutritional parameters influencing Nisin production by Lactococcus lactis subsp. lactis. J Biotechnol 63:229–233CrossRef Chandrapati S, O’Sullivan DJ (1998) Procedure for quantifiable assessment of nutritional parameters influencing Nisin production by Lactococcus lactis subsp. lactis. J Biotechnol 63:229–233CrossRef
go back to reference Dawson PL, Carl GD, Acton JC, Han IY (2002) Effect of lauric acid and nisin-impregnated soy-based films on the growth of Listeria monocytogenes on turkey bologna. Poultry Sci 81:721–726 Dawson PL, Carl GD, Acton JC, Han IY (2002) Effect of lauric acid and nisin-impregnated soy-based films on the growth of Listeria monocytogenes on turkey bologna. Poultry Sci 81:721–726
go back to reference Fang TJ, Tsai HC (2003) Growth patterns of Escherichia coli O157:H7 in ground beef treated with nisin, chelators organic acids and their combinations immobilized in calcium alginate gels. Food Microbiol 20:243–253CrossRef Fang TJ, Tsai HC (2003) Growth patterns of Escherichia coli O157:H7 in ground beef treated with nisin, chelators organic acids and their combinations immobilized in calcium alginate gels. Food Microbiol 20:243–253CrossRef
go back to reference Food and Drug Administration (FDA) (1988) Nisin preparation: affirmation of GRAS status as a direct human food ingredient. Federal Register 53:11247–11251 Food and Drug Administration (FDA) (1988) Nisin preparation: affirmation of GRAS status as a direct human food ingredient. Federal Register 53:11247–11251
go back to reference Food and Nutrition Board (1997) Dietary references intakes: calcium, phosphorus, magnesium, vitamin D and fluoride. In: Institute of Medicine (ed) Uses of dietary intakes, Food and Nutrition Board, vol 7. National Academy Press, Washington DC Food and Nutrition Board (1997) Dietary references intakes: calcium, phosphorus, magnesium, vitamin D and fluoride. In: Institute of Medicine (ed) Uses of dietary intakes, Food and Nutrition Board, vol 7. National Academy Press, Washington DC
go back to reference Fu G, Vary PS, Lin CT (2005) Anatase TiO2 nanocomposites for antimicrobial coating. J Phys Chem B 109:8889–8898CrossRef Fu G, Vary PS, Lin CT (2005) Anatase TiO2 nanocomposites for antimicrobial coating. J Phys Chem B 109:8889–8898CrossRef
go back to reference Hauben KJA, Wuytack EY, Scootjens CCF, Michiels CW (1996) High pressure transient sensitization of E. coli to lysozyme and nisin by disruption of outer membrane permeability. J Food Prot 59:350–355 Hauben KJA, Wuytack EY, Scootjens CCF, Michiels CW (1996) High pressure transient sensitization of E. coli to lysozyme and nisin by disruption of outer membrane permeability. J Food Prot 59:350–355
go back to reference Henning S, Metz R, Hammes WP (1986) Studies on the mode of action of nisin. Int J Food Microbiol 3:121–134CrossRef Henning S, Metz R, Hammes WP (1986) Studies on the mode of action of nisin. Int J Food Microbiol 3:121–134CrossRef
go back to reference Hewitt CJ, Bellara ST, Andreani A, Nebe-von-Caron G, Mcfarlane CM (2001) An evaluation of the antibacterial action of ceramic powder slurries using multiparameter flow cytometry. Biotechnol Lett 23:667–675CrossRef Hewitt CJ, Bellara ST, Andreani A, Nebe-von-Caron G, Mcfarlane CM (2001) An evaluation of the antibacterial action of ceramic powder slurries using multiparameter flow cytometry. Biotechnol Lett 23:667–675CrossRef
go back to reference Huang Z, Maness PC, Blakee DM, Wolfrum EJ, Smoliski SL, Jacoby WA (2000) Bacterial mode of titanium dioxide photocatalysis. J Photochem Photobiol A: Chem 130:163–170CrossRef Huang Z, Maness PC, Blakee DM, Wolfrum EJ, Smoliski SL, Jacoby WA (2000) Bacterial mode of titanium dioxide photocatalysis. J Photochem Photobiol A: Chem 130:163–170CrossRef
go back to reference Huang L, Li D, Lin Y, Evans DG, Duan X (2005) Influence of nano-MgO particle size on bactericidal action against Bacillus subtilis var. niger. Chin Sci Bull 50(6):514–519 Huang L, Li D, Lin Y, Evans DG, Duan X (2005) Influence of nano-MgO particle size on bactericidal action against Bacillus subtilis var. niger. Chin Sci Bull 50(6):514–519
go back to reference Jin T (2010) Inactivation of Listeria monocytogenes in skim milk and liquid egg white by antimicrobial bottle coating with polylactic acid and nisin. J Food Sci 75(2):M83–M88CrossRef Jin T (2010) Inactivation of Listeria monocytogenes in skim milk and liquid egg white by antimicrobial bottle coating with polylactic acid and nisin. J Food Sci 75(2):M83–M88CrossRef
go back to reference Jin T, Gurtler J (2011) Inactivation of Salmonella in liquid egg albumen by antimicrobial bottle coatings infused with allyl isothiocyanate, nisin and zinc oxide nanoparticles. J Appl Microbiol 110:704–712CrossRef Jin T, Gurtler J (2011) Inactivation of Salmonella in liquid egg albumen by antimicrobial bottle coatings infused with allyl isothiocyanate, nisin and zinc oxide nanoparticles. J Appl Microbiol 110:704–712CrossRef
go back to reference Jin T, Zhang H (2008) Biodegradable polylactic acid polymer with nisin for use in antimicrobial food packaging. J Food Sci 73(3):M127–M134CrossRef Jin T, Zhang H (2008) Biodegradable polylactic acid polymer with nisin for use in antimicrobial food packaging. J Food Sci 73(3):M127–M134CrossRef
go back to reference Jin T, Liu L, Sommers C, Zhang H, Boyd G (2009a) Radiation resistance and postirradiation proliferation of Listeria monocytogenes on ready-to-eat deli meat in the presence of pectin/nisin films. J Food Protect 72(3):644–649 Jin T, Liu L, Sommers C, Zhang H, Boyd G (2009a) Radiation resistance and postirradiation proliferation of Listeria monocytogenes on ready-to-eat deli meat in the presence of pectin/nisin films. J Food Protect 72(3):644–649
go back to reference Jin T, Liu LS, Zhang H, Hicks K (2009b) Antimicrobial activity of nisin incorporated in pectin and polylactic acid composite films against Listeria monocytogenes. Int J Food Sci Technol 44:322–329CrossRef Jin T, Liu LS, Zhang H, Hicks K (2009b) Antimicrobial activity of nisin incorporated in pectin and polylactic acid composite films against Listeria monocytogenes. Int J Food Sci Technol 44:322–329CrossRef
go back to reference Jin T, Sun D, Su Y, Zhang H, Sue HJ (2009c) Antimicrobial efficacy of zinc oxide quantum dots against Listeria monocytogenes, Salmonella Enteritidis, and Escherichia coli O157:H7. J Food Sci 74:M46–M52CrossRef Jin T, Sun D, Su Y, Zhang H, Sue HJ (2009c) Antimicrobial efficacy of zinc oxide quantum dots against Listeria monocytogenes, Salmonella Enteritidis, and Escherichia coli O157:H7. J Food Sci 74:M46–M52CrossRef
go back to reference Jin T, Sun D, Zhang H, Sue HJ (2009d) Application of zinc oxide quantum dots in food safety. In: Sahu SC, Casciano DA (eds) Nanotoxicity: from in vivo and in vitro models to health risk. Wiley Publisher, Hoboken, pp 81–95 Jin T, Sun D, Zhang H, Sue HJ (2009d) Application of zinc oxide quantum dots in food safety. In: Sahu SC, Casciano DA (eds) Nanotoxicity: from in vivo and in vitro models to health risk. Wiley Publisher, Hoboken, pp 81–95
go back to reference Jin T, Zhang H, Boyd G (2010) Incorporation of preservatives in polylactic acid films for inactivating Escherichia coli O157:H7 and extending microbiological shelf-life of strawberry puree. J Food Protect 73(5):812–818 Jin T, Zhang H, Boyd G (2010) Incorporation of preservatives in polylactic acid films for inactivating Escherichia coli O157:H7 and extending microbiological shelf-life of strawberry puree. J Food Protect 73(5):812–818
go back to reference Koper OB, Klabunde JS, Marchin GL, Klabunde KJ, Stoimenov PK, Babra L (2002) Nanoscale powders and formulations with biocidal activity toward spores and vegetative cells of Bacillus species, viruses, and toxins. Curr Microbiol 44:49–55CrossRef Koper OB, Klabunde JS, Marchin GL, Klabunde KJ, Stoimenov PK, Babra L (2002) Nanoscale powders and formulations with biocidal activity toward spores and vegetative cells of Bacillus species, viruses, and toxins. Curr Microbiol 44:49–55CrossRef
go back to reference Kourai H (1993) Immobilized microbiocide. J Antibact antifungal agents 21:331–337 (in Japanese) Kourai H (1993) Immobilized microbiocide. J Antibact antifungal agents 21:331–337 (in Japanese)
go back to reference Liu Y, He L, Mustapha A, Li H, Hu ZQ, Lin M (2009) Antibacterial activities of zinc oxide nanoparticles against Escherichia coli O157:H7. J Appl Microbiol 107:1193–1201CrossRef Liu Y, He L, Mustapha A, Li H, Hu ZQ, Lin M (2009) Antibacterial activities of zinc oxide nanoparticles against Escherichia coli O157:H7. J Appl Microbiol 107:1193–1201CrossRef
go back to reference Liu LS, Jin T, Coffin DR, Liu CK, Hick KB (2010) Poly(lactic acid) membranes containing bacteriocins and EDTA for inhibition of the surface growth of gram-negative bacteria. J Appl Polym Sci 117(1):486–492 Liu LS, Jin T, Coffin DR, Liu CK, Hick KB (2010) Poly(lactic acid) membranes containing bacteriocins and EDTA for inhibition of the surface growth of gram-negative bacteria. J Appl Polym Sci 117(1):486–492
go back to reference Makhluf S, Dror R, Nitzan Y, Abramovich Y, Jelinek R, Gedanken A (2005) Microwave-assisted synthesis of nanocrystalline MgO and its use as Bacteriocide. Adv Funct Mater 15:1708–1715CrossRef Makhluf S, Dror R, Nitzan Y, Abramovich Y, Jelinek R, Gedanken A (2005) Microwave-assisted synthesis of nanocrystalline MgO and its use as Bacteriocide. Adv Funct Mater 15:1708–1715CrossRef
go back to reference McCormick KE, Han IY, Acton JC, Sheldon BW, Dawson PL (2005) In-package pasteurization combined with biocide impregnated films to inhibit Listeria monocytogenes and Salmonella Typhimurium in turkey bologna. Food Sci 70(1):M52–M57CrossRef McCormick KE, Han IY, Acton JC, Sheldon BW, Dawson PL (2005) In-package pasteurization combined with biocide impregnated films to inhibit Listeria monocytogenes and Salmonella Typhimurium in turkey bologna. Food Sci 70(1):M52–M57CrossRef
go back to reference Millette M, Le Tien C, Smoragiewicz W, Lacroix M (2007) Inhibition of Staphylococcus aureus on beef by nisin-containing modified alginate films and beads. Food Control 18:878–884CrossRef Millette M, Le Tien C, Smoragiewicz W, Lacroix M (2007) Inhibition of Staphylococcus aureus on beef by nisin-containing modified alginate films and beads. Food Control 18:878–884CrossRef
go back to reference Moll GN, Clark J, Chan WC, Bycroft BW, Roberts GCK, Konings WM, Driessen AJM (1997) Role of transmembrane pH gradient and membrane binding in nisin pore formation. J Bacteriol 179:135–140 Moll GN, Clark J, Chan WC, Bycroft BW, Roberts GCK, Konings WM, Driessen AJM (1997) Role of transmembrane pH gradient and membrane binding in nisin pore formation. J Bacteriol 179:135–140
go back to reference Morones JR, Elechiguerra JL, Camacho A, Holt K, Kouri JB, Ramirez JT, Yacaman MJ (2005) The bactericidal effect of silver nanoparticles. Nanotechnology 16:2346–2353CrossRef Morones JR, Elechiguerra JL, Camacho A, Holt K, Kouri JB, Ramirez JT, Yacaman MJ (2005) The bactericidal effect of silver nanoparticles. Nanotechnology 16:2346–2353CrossRef
go back to reference Nel A, Xia T, Ma¨dler L, Li N (2006) Toxic potential of materials at the nanolevel. Science 311:622–627CrossRef Nel A, Xia T, Ma¨dler L, Li N (2006) Toxic potential of materials at the nanolevel. Science 311:622–627CrossRef
go back to reference Okouchi S, Murata R, Sugita H, Moriyoshi Y, Maeda N (1995) Calorimetric evaluation of the antimicrobial activities of calcined dolomite. J Antibact Antifungal Agents 26:109–114 (in Japanese) Okouchi S, Murata R, Sugita H, Moriyoshi Y, Maeda N (1995) Calorimetric evaluation of the antimicrobial activities of calcined dolomite. J Antibact Antifungal Agents 26:109–114 (in Japanese)
go back to reference Pal S, Tak YK, Song JM (2007) Does the antibacterial activity of silver nanoparticles depend on the shape of the nanoparticle? A study of the gram-negative bacterium Escherichia coli. Appl Environ Microbiol 73(6):1712–1720CrossRef Pal S, Tak YK, Song JM (2007) Does the antibacterial activity of silver nanoparticles depend on the shape of the nanoparticle? A study of the gram-negative bacterium Escherichia coli. Appl Environ Microbiol 73(6):1712–1720CrossRef
go back to reference Sawai J (2003) Quantitative evaluation of antibacterial activities of metallic oxide powders (ZnO, MgO and CaO) by conductimetric assay. J Microbiol Methods 54:177–182CrossRef Sawai J (2003) Quantitative evaluation of antibacterial activities of metallic oxide powders (ZnO, MgO and CaO) by conductimetric assay. J Microbiol Methods 54:177–182CrossRef
go back to reference Sawai J, Yoshikawa T (2004) Quantitative evaluation of antifungal activity of metallic oxide powders (MgO, CaO and ZnO) by an indirect conductimetric assay. J Appl Microbiol 96:803–809CrossRef Sawai J, Yoshikawa T (2004) Quantitative evaluation of antifungal activity of metallic oxide powders (MgO, CaO and ZnO) by an indirect conductimetric assay. J Appl Microbiol 96:803–809CrossRef
go back to reference Sawai J, Igarashi H, Hashimoto A, Kokugan T, Shimizu M (1995) Evaluation of growth inhibitory effect of ceramic powder slurry on bacteria by conductance method. J Chem Eng Jpn 28:288–293CrossRef Sawai J, Igarashi H, Hashimoto A, Kokugan T, Shimizu M (1995) Evaluation of growth inhibitory effect of ceramic powder slurry on bacteria by conductance method. J Chem Eng Jpn 28:288–293CrossRef
go back to reference Sawai J, Shoji S, Igarashi H, Hashimoto A, Kokugan T, Shimizu M, Kojima H (1998) Hydrogen peroxide as an antibacterial factor in zinc oxide powder slurry. J Ferment Bioeng 86:521–522CrossRef Sawai J, Shoji S, Igarashi H, Hashimoto A, Kokugan T, Shimizu M, Kojima H (1998) Hydrogen peroxide as an antibacterial factor in zinc oxide powder slurry. J Ferment Bioeng 86:521–522CrossRef
go back to reference Sawai J, Kojima H, Igarashi H, Hashimoto A, Shoji S, Shimizu M (1999) Bactericidal action of calcium oxide powder. Trans Mater Res Soc Jpn 24:667–670 Sawai J, Kojima H, Igarashi H, Hashimoto A, Shoji S, Shimizu M (1999) Bactericidal action of calcium oxide powder. Trans Mater Res Soc Jpn 24:667–670
go back to reference Sawai J, Kojima H, Igarashi H, Hashimoto A, Shoji S, Sawaki T, Hakoda A, Kawada E, Kokugan T, Shimizu M (2000) Antibacterial characteristics of magnesium oxide powder. World J Microbiol Biotechnol 16:187–194CrossRef Sawai J, Kojima H, Igarashi H, Hashimoto A, Shoji S, Sawaki T, Hakoda A, Kawada E, Kokugan T, Shimizu M (2000) Antibacterial characteristics of magnesium oxide powder. World J Microbiol Biotechnol 16:187–194CrossRef
go back to reference Sheldon BW (2001) Development of an inhibitory absorbent cellulose gum tray pads for reducing spoilage microorganisms and the risk of cross contamination. Poult Sci 80(Suppl 1):17 Sheldon BW (2001) Development of an inhibitory absorbent cellulose gum tray pads for reducing spoilage microorganisms and the risk of cross contamination. Poult Sci 80(Suppl 1):17
go back to reference Shi LE, Xing L, Hou B, Ge H, Guo X, Tang Z (2010) Inorganic nano mental oxides used as anti-microorganism agents for pathogen control. In: Mendez-Vilas A (ed) Current research education technology topics in applied microbiology, microbial biotechnology. Formatex Research Center, Badajoz Shi LE, Xing L, Hou B, Ge H, Guo X, Tang Z (2010) Inorganic nano mental oxides used as anti-microorganism agents for pathogen control. In: Mendez-Vilas A (ed) Current research education technology topics in applied microbiology, microbial biotechnology. Formatex Research Center, Badajoz
go back to reference Shirashi F, Toyoda K, Fukinbara S (1999) Photolytic smf photocatalytic treatment of an aqueous solution containing microbial cells and organic compounds in an annular-flow reactor. Chem Eng Sci 54:1547–1552CrossRef Shirashi F, Toyoda K, Fukinbara S (1999) Photolytic smf photocatalytic treatment of an aqueous solution containing microbial cells and organic compounds in an annular-flow reactor. Chem Eng Sci 54:1547–1552CrossRef
go back to reference Steels H, James SA, Roberts IN, Stratford M (2000) Sorbic acid resistance: the inoculum effect. Yeast 16:1173–1183CrossRef Steels H, James SA, Roberts IN, Stratford M (2000) Sorbic acid resistance: the inoculum effect. Yeast 16:1173–1183CrossRef
go back to reference Stoimenov PK, Klinger RL, Marchin GL, Klabunde KJ (2002) Metal oxide nanoparticles as bactericidal agents. Langmuir 18:6679–6686CrossRef Stoimenov PK, Klinger RL, Marchin GL, Klabunde KJ (2002) Metal oxide nanoparticles as bactericidal agents. Langmuir 18:6679–6686CrossRef
go back to reference Ukuku DO, Fett W (2004) Effect of nisin in combination with EDTA, sodium lactate, and potassium sorbate for reducing Salmonella on whole and fresh-cut cantaloupe. J Food Prot 67(10):2143–2150 Ukuku DO, Fett W (2004) Effect of nisin in combination with EDTA, sodium lactate, and potassium sorbate for reducing Salmonella on whole and fresh-cut cantaloupe. J Food Prot 67(10):2143–2150
go back to reference Wang YL, Wan YZ, Dong XH, Cheng GX, Tao HM, Wen TY (1995) Preparation and characterization of antibacterial viscose-based activated carbon fiber supporting silver. Carbon 36:1567–1571CrossRef Wang YL, Wan YZ, Dong XH, Cheng GX, Tao HM, Wen TY (1995) Preparation and characterization of antibacterial viscose-based activated carbon fiber supporting silver. Carbon 36:1567–1571CrossRef
go back to reference Wang YL, Wan YZ, Dong H, Cheng GX, Tao HM, Wen TY (1998) Preparation and characterization of antibacterial viscose-based activated carbon fibre supporting silver. Carbon 36:1567–1571CrossRef Wang YL, Wan YZ, Dong H, Cheng GX, Tao HM, Wen TY (1998) Preparation and characterization of antibacterial viscose-based activated carbon fibre supporting silver. Carbon 36:1567–1571CrossRef
go back to reference Wilczynski M (2000) Anti-microbial porcelain enamels. Ceram Eng Sci Proc 21:81–83 Wilczynski M (2000) Anti-microbial porcelain enamels. Ceram Eng Sci Proc 21:81–83
go back to reference Xie Y, He Y, Irwin P, Jin T, Shi X (2011) Antibacterial activity and mechanism of zinc oxide nanoparticles against Campylobacter jejuni. Appl Environ Microbiol 77(7):2325–2331CrossRef Xie Y, He Y, Irwin P, Jin T, Shi X (2011) Antibacterial activity and mechanism of zinc oxide nanoparticles against Campylobacter jejuni. Appl Environ Microbiol 77(7):2325–2331CrossRef
go back to reference Yamamoto O (2001) Influence of particle size on the antibacterial activity of zinc oxide. Int J Inorgan Mater 3:643–646CrossRef Yamamoto O (2001) Influence of particle size on the antibacterial activity of zinc oxide. Int J Inorgan Mater 3:643–646CrossRef
Metadata
Title
Antibacterial activities of magnesium oxide (MgO) nanoparticles against foodborne pathogens
Authors
Tony Jin
Yiping He
Publication date
01-12-2011
Publisher
Springer Netherlands
Published in
Journal of Nanoparticle Research / Issue 12/2011
Print ISSN: 1388-0764
Electronic ISSN: 1572-896X
DOI
https://doi.org/10.1007/s11051-011-0595-5

Other articles of this Issue 12/2011

Journal of Nanoparticle Research 12/2011 Go to the issue

Premium Partners