Real-Time Manganese Phase Dynamics during Biological and Abiotic Manganese Oxide Reduction

Environmental Science and Technology

Volumn 50, Issue 8, 2016, Pages 4248-4258

  Johnson, Jena E ^a,e   Savalia, Pratixa ^b   Davis, Ryan ^c   Kocar, Benjamin D ^d   Webb, Samuel M ^c   Nealson, Kenneth H ^b   Fischer, Woodward W ^a  

^a CALIFORNIA INSTITUTE OF TECHNOLOGY   (United States)

^b UNIVERSITY OF SOUTHERN CALIFORNIA   (United States)

^c SLAC NATIONAL ACCELERATOR LABORATORY   (United States)

^d MASSACHUSETTS INSTITUTE OF TECHNOLOGY   (United States)

^e UNIVERSITY OF COLORADO   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ALKALINITY; BACTERIA; CARBON; INORGANIC CHEMICALS; MANGANESE; MICROORGANISMS; OXIDES; X RAY DIFFRACTION; X RAY SPECTROSCOPY;

ANAEROBIC RESPIRATION; PHOSPHATE AVAILABILITY; REACTION MECHANISM; REAL TIME MEASUREMENTS; SHEWANELLA ONEIDENSIS MR-1; SOLUTION CONDITIONS; SPECTROSCOPIC MEASUREMENTS; SYNCHROTRON X RAYS;

MANGANESE OXIDE;

FERROUS ION; MANGANESE; MANGANESE OXIDE; CARBONIC ACID DERIVATIVE; IRON; MANGANESE CARBONATE; MANGANESE DERIVATIVE; MANGANESE PHOSPHATE; ORGANOMETALLIC COMPOUND; OXIDE; SULFIDE; WATER;

ANOXIC CONDITIONS; BACTERIUM; BIOLOGICAL ANALYSIS; MANGANESE; MICROBIAL ACTIVITY; OXIDE; REAL TIME; REDUCTION; RESPIRATION;

ALKALINITY; ARTICLE; CONTROLLED STUDY; DYNAMICS; ELECTRON; MICROORGANISM; NONHUMAN; RAMAN SPECTROMETRY; REACTION ANALYSIS; REDUCTION; ROENTGEN SPECTROSCOPY; SHEWANELLA ONEIDENSIS; SYNCHROTRON RADIATION; X RAY DIFFRACTION; BIOREMEDIATION; CHEMISTRY; METABOLISM; OXIDATION REDUCTION REACTION; SHEWANELLA; X RAY ABSORPTION SPECTROSCOPY;

SHEWANELLA ONEIDENSIS MR-1;

BIODEGRADATION, ENVIRONMENTAL; CARBONATES; IRON; MANGANESE; MANGANESE COMPOUNDS; ORGANOMETALLIC COMPOUNDS; OXIDATION-REDUCTION; OXIDES; SHEWANELLA; SPECTRUM ANALYSIS, RAMAN; SULFIDES; WATER; X-RAY ABSORPTION SPECTROSCOPY; X-RAY DIFFRACTION;

EID: 84966335377     PISSN: 0013936X     EISSN: 15205851     Source Type: Journal    
DOI: 10.1021/acs.est.5b04834     Document Type: Article

References (75)

1. Tebo, B. M.; Johnson, H. A.; McCarthy, J. K.; Templeton, A. S. Geomicrobiology of manganese(II) oxidation Trends Microbiol. 2005, 13 (9) 421-428 10.1016/j.tim.2005.07.009
2. Lovley, D. R.; Phillips, E. J. P. Novel Mode of Microbial Energy Metabolism: Organic Carbon Oxidation Coupled to Dissimilatory Reduction of Iron or Manganese Appl. Environ. Microbiol. 1988, 54 (6) 1472-1480
3. Myers, C. R.; Nealson, K. H. Bacterial manganese reduction and growth with manganese oxide as the sole electron acceptor Science 1988, 240 (4857) 1319-1321 10.1126/science.240.4857.1319
4. Burdige, D. J.; Dhakar, S. P.; Nealson, K. H. Effects of manganese oxide mineralogy on microbial and chemical manganese reduction Geomicrobiol. J. 1992, 10 (1) 27-48 10.1080/01490459209377902
5. Van Cappellen, P.; Viollier, E.; Roychoudhury, A.; Clark, L.; Ingall, E.; Lowe, K.; Dichristina, T. Biogeochemical Cycles of Manganese and Iron at the Oxic-Anoxic Transition of a Stratified Marine Basin (Orca Basin, Gulf of Mexico) Environ. Sci. Technol. 1998, 32 (19) 2931-2939 10.1021/es980307m
6. Canfield, D. E.; Thamdrup, B.; Hansen, J. W. The anaerobic degradation of organic matter in Danish coastal sediments: Iron reduction, manganese reduction, and sulfate reduction Geochim. Cosmochim. Acta 1993, 57 (16) 3867-3883 10.1016/0016-7037(93)90340-3
7. Thamdrup, B.; Rosselló-Mora, R.; Amann, R. Microbial Manganese and Sulfate Reduction in Black Sea Shelf Sediments Appl. Environ. Microbiol. 2000, 66 (7) 2888-2897 10.1128/AEM.66.7.2888-2897.2000
8. Burdige, D. J.; Nealson, K. H. Chemical and microbiological studies of sulfide-mediated manganese reduction Geomicrobiol. J. 1986, 4 (4) 361-387 10.1080/01490458609385944
9. Myers, C. R.; Nealson, K. H. Microbial reduction of manganese oxides: Interactions with iron and sulfur Geochim. Cosmochim. Acta 1988, 52 (11) 2727-2732 10.1016/0016-7037(88)90041-5
10. Ying, S. C.; Kocar, B. D.; Griffis, S. D.; Fendorf, S. Competitive Microbially and Mn Oxide Mediated Redox Processes Controlling Arsenic Speciation and Partitioning Environ. Sci. Technol. 2011, 45 (13) 5572-5579 10.1021/es200351m
11. Fredrickson, J. K.; Zachara, J. M.; Kennedy, D. W.; Liu, C.; Duff, M. C.; Hunter, D. B.; Dohnalkova, A. Influence of Mn oxides on the reduction of uranium(VI) by the metal-reducing bacterium Shewanella putrefaciens Geochim. Cosmochim. Acta 2002, 66 (18) 3247-3262 10.1016/S0016-7037(02)00928-6
12. Thamdrup, B.; Finster, K.; Hansen, J. W.; Bak, F. Bacterial Disproportionation of Elemental Sulfur Coupled to Chemical Reduction of Iron or Manganese Appl. Environ. Microbiol. 1993, 59 (1) 101-108
13. Thamdrup, B.; Glud, R. N.; Hansen, J. W. Manganese oxidation and in situ manganese fluxes from a coastal sediment Geochim. Cosmochim. Acta 1994, 58 (11) 2563-2570 10.1016/0016-7037(94)90032-9
14. van Cappellen, P.; Wang, Y. Cycling of iron and manganese in surface sediments; a general theory for the coupled transport and reaction of carbon, oxygen, nitrogen, sulfur, iron, and manganese Am. J. Sci. 1996, 296 (3) 197-243 10.2475/ajs.296.3.197
15. Wang, Z.; Giammar, D. E. Metal Contaminant Oxidation Mediated by Manganese Redox Cycling in Subsurface Environment. In Advances in the Environmental Biogeochemistry of Manganese Oxides; ACS Symposium Series; American Chemical Society: Washington, DC, 2015; Vol. 1197, pp 29-50.
16. Dick, G. J.; Clement, B. G.; Webb, S. M.; Fodrie, F. J.; Bargar, J. R.; Tebo, B. M. Enzymatic microbial Mn(II) oxidation and Mn biooxide production in the Guaymas Basin deep-sea hydrothermal plume Geochim. Cosmochim. Acta 2009, 73, 6517-6530 10.1016/j.gca.2009.07.039
17. Fuller, C. C.; Harvey, J. W. Reactive Uptake of Trace Metals in the Hyporheic Zone of a Mining-Contaminated Stream, Pinal Creek, Arizona Environ. Sci. Technol. 2000, 34 (7) 1150-1155 10.1021/es990714d
18. Tebo, B. M.; Rosson, R. A.; Nealson, K. H. Potential for manganese(II) oxidation and manganese(IV) reduction to co-occur in the anoxic non-sulfidic zone of the Black Sea. In Black Sea Oceanography; Izdar, E.; Murray, J. W., Eds.; Kluwer Academic Publishers: Dordrecht, The Netherlands, 1991; pp 173-185.
19. Lin, H.; Szeinbaum, N. H.; DiChristina, T. J.; Taillefert, M. Microbial Mn(IV) reduction requires an initial one-electron reductive solubilization step Geochim. Cosmochim. Acta 2012, 99, 179-192 10.1016/j.gca.2012.09.020
20. Madison, A. S.; Tebo, B. M.; Mucci, A.; Sundby, B.; Luther, G. W. Abundant Porewater Mn(III) Is a Major Component of the Sedimentary Redox System Science 2013, 341 (6148) 875-878 10.1126/science.1241396
21. Froelich, P. N.; Klinkhammer, G. P.; Bender, M. L.; Luedtke, N. A.; Heath, G. R.; Cullen, D.; Dauphin, P.; Hammond, D.; Hartman, B.; Maynard, V. Early oxidation of organic matter in pelagic sediments of the eastern equatorial Atlantic: suboxic diagenesis Geochim. Cosmochim. Acta 1979, 43 (7) 1075-1090 10.1016/0016-7037(79)90095-4
22. Nealson, K. H.; Saffarini, D. Iron and Manganese in Anaerobic Respiration: Environmental Significance, Physiology, and Regulation Annu. Rev. Microbiol. 1994, 48 (1) 311-343 10.1146/annurev.mi.48.100194.001523
23. Roy, S. Sedimentary manganese metallogenesis in response to the evolution of the Earth system Earth-Sci. Rev. 2006, 77 (4) 273-305 10.1016/j.earscirev.2006.03.004
24. Maynard, J. B. The Chemistry of Manganese Ores through Time: A Signal of Increasing Diversity of Earth-Surface Environments Econ. Geol. Bull. Soc. Econ. Geol. 2010, 105 (3) 535-552 10.2113/gsecongeo.105.3.535
25. Calvert, S. E.; Pedersen, T. F. Sedimentary geochemistry of manganese; implications for the environment of formation of manganiferous black shales Econ. Geol. Bull. Soc. Econ. Geol. 1996, 91 (1) 36-47 10.2113/gsecongeo.91.1.36
26. Johnson, J. E.; Webb, S. M.; Ma, C.; Fischer, W. W. Manganese mineralogy and diagenesis in the sedimentary rock record Geochim. Cosmochim. Acta 2016, 173, 210-231 10.1016/j.gca.2015.10.027
27. Webb, S. M.; Tebo, B. M.; Bargar, J. R. Structural characterization of biogenic Mn oxides produced in seawater by the marine bacillus sp. strain SG-1 Am. Mineral. 2005, 90 (8-9) 1342-1357 10.2138/am.2005.1669
28. Bargar, J. R.; Tebo, B. M.; Villinski, J. E. In situ characterization of Mn(II) oxidation by spores of the marine Bacillus sp. strain SG-1 Geochim. Cosmochim. Acta 2000, 64, 2775-2778 10.1016/S0016-7037(00)00368-9
29. Murray, J. W.; Dillard, J. G.; Giovanoli, R.; Moers, H.; Stumm, W. Oxidation of Mn(II): Initial mineralogy, oxidation state and ageing Geochim. Cosmochim. Acta 1985, 49 (2) 463-470 10.1016/0016-7037(85)90038-9
30. Wehrli, B.; Friedl, G.; Manceau, A. Reaction Rates and Products of Manganese Oxidation at the Sediment-Water Interface. In Aquatic Chemistry; Advances in Chemistry; American Chemical Society: Washington, DC, 1995; Vol. 244, pp 111-134.
31. McKeown, D. A.; Post, J. E. Characterization of manganese oxide mineralogy in rock varnish and dendrites using X-ray absorption spectroscopy Am. Mineral. 2001, 86 (5-6) 701-713 10.2138/am-2001-5-611
32. Tebo, B. M.; Bargar, J. R.; Clement, B. G.; Dick, G. J.; Murray, K. J.; Parker, D.; Verity, R.; Webb, S. M. BIOGENIC MANGANESE OXIDES: Properties and Mechanisms of Formation Annu. Rev. Earth Planet. Sci. 2004, 32 (1) 287-328 10.1146/annurev.earth.32.101802.120213
33. De Schamphelaire, L.; Rabaey, K.; Boon, N.; Verstraete, W.; Boeckx, P. Minireview: The Potential of Enhanced Manganese Redox Cycling for Sediment Oxidation Geomicrobiol. J. 2007, 24 (7-8) 547-558 10.1080/01490450701670137
34. Coleman, M. L.; Fleet, A.; Donson, P. Preliminary Studies of Manganese-Rich Carbonate Nodules from Leg 68, Site 503, Eastern Equatorial Pacific; Init. Repts. DSDP 68; 1982; pp 481-489.
35. Johnson, J. E.; Webb, S. M.; Thomas, K.; Ono, S.; Kirschvink, J. L.; Fischer, W. W. Manganese-oxidizing photosynthesis before the rise of cyanobacteria Proc. Natl. Acad. Sci. U. S. A. 2013, 110 (28) 11238-11243 10.1073/pnas.1305530110
36. Tsikos, H.; Beukes, N. J.; Moore, J. M.; Harris, C. Deposition, Diagenesis, and Secondary Enrichment of Metals in the Paleoproterozoic Hotazel Iron Formation, Kalahari Manganese Field, South Africa Econ. Geol. Bull. Soc. Econ. Geol. 2003, 98 (7) 1449-1462 10.2113/gsecongeo.98.7.1449
37. Okita, P. M.; Maynard, J. B.; Spiker, E. C.; Force, E. R. Isotopic evidence for organic matter oxidation by manganese reduction in the formation of stratiform manganese carbonate ore Geochim. Cosmochim. Acta 1988, 52 (11) 2679-2685 10.1016/0016-7037(88)90036-1
38. Böttcher, M. E.; Thamdrup, B. Anaerobic sulfide oxidation and stable isotope fractionation associated with bacterial sulfur disproportionation in the presence of MnO2 Geochim. Cosmochim. Acta 2001, 65 (10) 1573-1581 10.1016/S0016-7037(00)00622-0
39. Meister, P.; Bernasconi, S. M.; Aiello, I. W.; Vasconcelos, C.; Mckenzie, J. A. Depth and controls of Ca-rhodochrosite precipitation in bioturbated sediments of the Eastern Equatorial Pacific, ODP Leg 201, Site 1226 and DSDP Leg 68, Site 503 Sedimentology 2009, 56 (5) 1552-1568 10.1111/j.1365-3091.2008.01046.x
40. Huckriede, H.; Meischner, D. Origin and environment of manganese-rich sediments within black-shale basins Geochim. Cosmochim. Acta 1996, 60 (8) 1399-1413 10.1016/0016-7037(96)00008-7
41. Lee, J.-H.; Kennedy, D. W.; Dohnalkova, A.; Moore, D. A.; Nachimuthu, P.; Reed, S. B.; Fredrickson, J. K. Manganese sulfide formation via concomitant microbial manganese oxide and thiosulfate reduction Environ. Microbiol. 2011, 13 (12) 3275-3288 10.1111/j.1462-2920.2011.02587.x
42. Fischer, T. B.; Heaney, P. J.; Jang, J.-H.; Ross, D. E.; Brantley, S. L.; Post, J. E.; Tien, M. Continuous time-resolved X-ray diffraction of the biocatalyzed reduction of Mn oxide Am. Mineral. 2008, 93 (11-12) 1929-1932 10.2138/am.2008.3038
43. Venkateswaran, K.; Moser, D. P.; Dollhopf, M. E.; Lies, D. P.; Saffarini, D. A.; MacGregor, B. J.; Ringelberg, D. B.; White, D. C.; Nishijima, M.; Sano, H. et al. Polyphasic taxonomy of the genus Shewanella and description of Shewanella oneidensis sp. nov Int. J. Syst. Bacteriol. 1999, 49 (2) 705-724 10.1099/00207713-49-2-705
44. Brown, G. E.; Sturchio, N. C. An Overview of Synchrotron Radiation Applications to Low Temperature Geochemistry and Environmental Science Rev. Mineral. Geochem. 2002, 49 (1) 1-115 10.2138/gsrmg.49.1.1
45. Kostka, J.; Nealson, K. H. Isolation, Cultivation and Characterization of Iron- and Manganese-Reducing Bacteria. In Techniques in Microbial Ecology; Burlage, R. S.; Atlas, R.; Stahl, D.; Geesey, G.; Sayler, G., Eds.; Oxford University Press: Oxford, 1998; p 468.
46. Butler, I. B.; Schoonen, M. A. A.; Rickard, D. T. Removal of dissolved oxygen from water: A comparison of four common techniques Talanta 1994, 41 (2) 211-215 10.1016/0039-9140(94)80110-X
47. Richardson, D. J.; Butt, J. N.; Fredrickson, J. K.; Zachara, J. M.; Shi, L.; Edwards, M. J.; White, G.; Baiden, N.; Gates, A. J.; Marritt, S. J. et al. The "porin-cytochrome" model for microbe-to-mineral electron transfer Mol. Microbiol. 2012, 85 (2) 201-212 10.1111/j.1365-2958.2012.08088.x
48. Harris, H. W.; El-Naggar, M. Y.; Bretschger, O.; Ward, M. J.; Romine, M. F.; Obraztsova, A. Y.; Nealson, K. H. Electrokinesis is a microbial behavior that requires extracellular electron transport Proc. Natl. Acad. Sci. U. S. A. 2010, 107 (1) 326-331 10.1073/pnas.0907468107
49. Marsili, E.; Baron, D. B.; Shikhare, I. D.; Coursolle, D.; Gralnick, J. A.; Bond, D. R. Shewanella secretes flavins that mediate extracellular electron transfer Proc. Natl. Acad. Sci. U. S. A. 2008, 105 (10) 3968-3973 10.1073/pnas.0710525105
50. Kotloski, N. J.; Gralnick, J. A. Flavin electron shuttles dominate extracellular electron transfer by Shewanella oneidensis mBio 2013, 4 (1) 1-4 10.1128/mBio.00553-12
51. Gorby, Y. A.; Yanina, S.; McLean, J. S.; Rosso, K. M.; Moyles, D.; Dohnalkova, A.; Beveridge, T. J.; Chang, I. S.; Kim, B. H.; Kim, K. S. et al. Electrically conductive bacterial nanowires produced by Shewanella oneidensis strain MR-1 and other microorganisms Proc. Natl. Acad. Sci. U. S. A. 2006, 103 (30) 11358-11363 10.1073/pnas.0604517103
52. Myers, C. R.; Myers, J. M. Localization of cytochromes to the outer membrane of anaerobically grown Shewanella putrefaciens MR-1 J. Bacteriol. 1992, 174 (11) 3429-3438
53. Okamoto, A.; Hashimoto, K.; Nealson, K. H.; Nakamura, R. Rate enhancement of bacterial extracellular electron transport involves bound flavin semiquinones Proc. Natl. Acad. Sci. U. S. A. 2013, 110 (19) 7856-7861 10.1073/pnas.1220823110
54. Bergmann, K. D.; Grotzinger, J. P.; Fischer, W. W. Biological Influences on Seafloor Carbonate Precipitation Palaios 2013, 28 (2) 99-115 10.2110/palo.2012.p12-088r
55. Manceau, A.; Marcus, M. A.; Grangeon, S. Determination of Mn valence states in mixed-valent manganates by XANES spectroscopy Am. Mineral. 2012, 97, 816-827 10.2138/am.2012.3903
56. Bargar, J. R.; Webb, S. M.; Tebo, B.M. Structural Determination of Marine Bacteriogenic Manganese Oxides SSRL Sci. Highlight 2005, 1-4
57. Webb, S. M.; Dick, G. J.; Bargar, J. R.; Tebo, B. M. Evidence for the presence of Mn(III) intermediates in the bacterial oxidation of Mn(II) Proc. Natl. Acad. Sci. U. S. A. 2005, 102 (15) 5558-5563 10.1073/pnas.0409119102
58. Luther, G. W. I. The Role of One- and Two-Electron Transfer Reactions in Forming Thermodynamically Unstable Intermediates as Barriers in Multi-Electron Redox Reactions Aquat. Geochem. 2010, 16 (3) 395-420 10.1007/s10498-009-9082-3
59. Morgan, J. J.; Stumm, W. Colloid-chemical properties of manganese dioxide J. Colloid Sci. 1964, 19 (4) 347-359 10.1016/0095-8522(64)90036-4
60. Bargar, J. R.; Tebo, B. M.; Bergmann, U.; Webb, S. M.; Glatzel, P.; Chiu, V. Q.; Villalobos, M. Biotic and abiotic products of Mn(II) oxidation by spores of the marine Bacillus sp. strain SG-1 Am. Mineral. 2005, 90 (1) 143-154 10.2138/am.2005.1557
61. Webb, S. M. SIXpack: a graphical user interface for XAS analysis using IFEFFIT Phys. Scr. 2005, 2005 (T115) 1011 10.1238/Physica.Topical.115a01011
62. Ball, J. W.; Nordstrom, D. K. WATEQ4F - User's manual with revised thermodynamic data base and test cases for calculating speciation of major, trace and redox elements in natural waters; Open-File Report; USGS Numbered Series 90-129; 1991.
63. Conkright, M. E.; Garcia, H. E.; O'Brien, T. D.; Locarnini, R. A.; Boyer, T. P.; Antonov, C. S. World Ocean Atlas 2001; Levitus, E., Ed.; NOAA Atlas NESDIS 52; U.S. Gov. Printing Office: Washington, DC, 2002; Vol. 4: Nutrients.
64. Williams, R. G.; Follows, M. J. Ocean Dynamics and the Carbon Cycle: Principles and Mechansims; Cambridge University Press: New York, 2011.
65. Elzinga, E. J. Reductive Transformation of Birnessite by Aqueous Mn(II) Environ. Sci. Technol. 2011, 45 (15) 6366-6372 10.1021/es2013038
66. Mandernack, K. W.; Post, J.; Tebo, B. M. Manganese mineral formation by bacterial spores of the marine Bacillus, strain SG-1: Evidence for the direct oxidation of Mn(II) to Mn(IV) Geochim. Cosmochim. Acta 1995, 59 (21) 4393-4408 10.1016/0016-7037(95)00298-E
67. Siebecker, M.; Madison, A. S.; Luther, G. W., III Reduction Kinetics of Polymeric (Soluble) Manganese (IV) Oxide (MnO2) by Ferrous Iron (Fe2+) Aquat. Geochem. 2015, 21 (2-4) 143-158 10.1007/s10498-015-9257-z
68. Nico, P. S.; Zasoski, R. J. Mn(III) Center Availability as a Rate Controlling Factor in the Oxidation of Phenol and Sulfide on δ-MnO2 Environ. Sci. Technol. 2001, 35 (16) 3338-3343 10.1021/es001848q
69. Herszage, J.; dos Santos Afonso, M. Mechanism of Hydrogen Sulfide Oxidation by Manganese(IV) Oxide in Aqueous Solutions Langmuir 2003, 19 (23) 9684-9692 10.1021/la034016p
70. Kostka, J. E.; Luther, G. W. I.; Nealson, K. H. Chemical and biological reduction of Mn(III)-pyrophosphate complexes: Potential importance of dissolved Mn(III) as an environmental oxidant Geochim. Cosmochim. Acta 1995, 59 (5) 885-894 10.1016/0016-7037(95)00007-0
71. Oldham, V. E.; Owings, S. M.; Jones, M. R.; Tebo, B. M.; Luther, G. W., III Evidence for the presence of strong Mn(III)-binding ligands in the water column of the Chesapeake Bay Mar. Chem. 2015, 171, 58-66 10.1016/j.marchem.2015.02.008
72. Yao, W.; Millero, F. J. The rate of sulfide oxidation by δMnO2 in seawater Geochim. Cosmochim. Acta 1993, 57 (14) 3359-3365 10.1016/0016-7037(93)90544-7
73. Hem, J. D.; Lind, C. J. Nonequilibrium models for predicting forms of precipitated manganese oxides Geochim. Cosmochim. Acta 1983, 47 (11) 2037-2046 10.1016/0016-7037(83)90219-3
74. Robie, R. A.; Huebner, J. S.; Hemingway, B. S. Heat capacities and thermodynamic properties of braunite (Mn7SiO12) and rhodonite (MnSiO3) Am. Mineral. 1995, 80, 560-575 10.2138/am-1995-5-615
75. Gutzmer, J.; Beukes, N. J. Mineral paragenesis of the Kalahari managanese field, South Africa Ore Geol. Rev. 1996, 11 (6) 405-428 10.1016/S0169-1368(96)00011-X