Microbiologically induced calcite precipitation

Microbiologically induced calcium carbonate precipitation (MICP) is a bio-geochemical process that induces calcium carbonate precipitation within the soil matrix.[1] Biomineralization in the form of calcium carbonate precipitation can be traced back to the Precambrian period.[2] Calcium carbonate can be precipitated in three polymorphic forms, which in the order of their usual stabilities are calcite, aragonite and vaterite.[3] The main groups of microorganisms that can induce the carbonate precipitation are photosynthetic microorganisms such as cyanobacteria and microalgae; sulfate-reducing bacteria; and some species of microorganisms involved in nitrogen cycle.[4] Several mechanisms have been identified by which bacteria can induce the calcium carbonate precipitation, including urea hydrolysis, denitrification, sulphate production, and iron reduction. Two different pathways, or autotrophic and heterotrophic pathways, through which calcium carbonate is produced have been identified. There are three autotrophic pathways, which all result in depletion of carbon dioxide and favouring calcium carbonate precipitation.[5] In heterotrophic pathway, two metabolic cycles can be involved: the nitrogen cycle and the sulfur cycle.[6] Several applications of this process have been proposed, such as remediation of cracks and corrosion prevention in concrete,[7][8][9][10][11][12][13][14][15] biogrout,[16][17][18][19][20][21][22][23] sequestration of radionuclides and heavy metals.[24][25][26][27][28][29]

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Biomineralization
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Metabolic pathways

Autotrophic pathway

All three principal kinds of bacteria that are involved in autotrophic production of carbonate obtain carbon from gaseous or dissolved carbon dioxide.[30] These pathways include non-methylotrophic methanogenesis, anoxygenic photosynthesis, and oxygenic photosynthesis. Non-methylotrophic methanogegenesis is carried out by methanogenic archaebacteria, which use CO2 and H2 in anaerobiosis to give CH4.[30]

Heterotrophic pathway

Two separate and often concurrent heterotrophic pathways that lead to calcium carbonate precipitation may occur, including active and passive carbonatogenesis. During active carbonatogenesis, the carbonate particles are produced by ionic exchanges through the cell membrane by activation of calcium and/or magnesium ionic pumps or channels, probably coupled with carbonate ion production.[30] During passive carbonatogenesis, two metabolic cycles can be involved, the nitrogen cycle and the sulfur cycle. Three different pathways can be involved in the nitrogen cycle: ammonification of amino acids, dissimilatory reduction of nitrate, and degradation of urea or uric acid.[7][31] In sulfur cycle, bacteria follow the dissimilatory reduction of sulfate.[30]

Ureolysis or Degradation of Urea

The microbial urease catalyzes the hydrolysis of urea into ammonium and carbonate.[19] One mole of urea is hydrolyzed intracellularly to 1 mol of ammonia and 1 mole of Carbamic acid (1), which spontaneously hydrolyzes to form an additional 1 mole of ammonia and carbonic acid (2).[6][32]

CO(NH2)2 + H2O ---> NH2COOH + NH3 (1)

NH2COOH + H2O ---> NH3 + H2CO3 (2)

Ammonium and carbonic acid form bicarbonate and 2 moles of ammonium and hydroxide ions in water (3 &4).

2NH3 + 2H2O <---> 2NH+4 +2OH− (3) H2CO3 <---> HCO−3 + H+ (4)

The production of hydroxide ions results in the increase of pH,[33] which in turn can shift the bicarbonate equilibrium, resulting in the formation of carbonate ions (5)

HCO−3 + H+ + 2NH+4 +2OH− <---> CO3−2 + 2NH+4 + 2H2O (5)

The produced carbonate ions precipitate in the presence of calcium ions as calcium carbonate crystals (6).

Ca+2 + CO3−2 <---> CaCO3 (6)

The formation of a monolayer of calcite further increases the affinity of the bacteria to the soil surface, resulting in the production of multiple layers of calcite.

Possible applications

Material science

MICP has been reported as a long-term remediation technique that has been exhibited high potential for crack cementation of various structural formations such as granite and concrete.[34]

Treatment of concrete

MICP has been shown to prolong concrete service life due to calcium carbonate precipitation. The calcium carbonate heals the concrete by solidifying on the cracked concrete surface, mimicking the process by which bone fractures in human body are healed by osteoblast cells that mineralize to reform the bone.[34] Two methods are currently being studied: injection of calcium carbonate precipitating bacteria.[11][12][35][36] and by applying bacteria and nutrients as a surface treatment.[9][37] Increase in strength and durability of MICP treated concrete has been reported.[38]

Bricks

Architect Ginger Krieg Dosier won the 2010 Metropolis Next Generation Design Competition for her work using microbial-induced calcite precipitation to manufacture bricks while lowering carbon dioxide emissions.[39] She has since founded bioMASON, Inc., a company that employs microorganisms and chemical processes to manufacture building materials.

Fillers for rubber, plastics and ink

MICP technique may be applied to produce a material that can be used as a filler in rubber and plastics, fluorescent particles in stationery ink, and a fluorescent marker for biochemistry applications, such as western blot.[40]

Liquefaction prevention

Microbial induced calcium carbonate precipitation has been proposed as an alternative cementation technique to improve the properties of potentially liquefiable sand.[1][17][19][20][21] The increase in shear strength, confined compressive strength, stiffness and liquefaction resistance was reported due to calcium carbonate precipitation resulting from microbial activity.[18][19][21][23] The increase of soil strength from MICP is a result of the bonding of the grains and the increased density of the soil.[41] Research has shown a linear relationship between the amount of carbonate precipitation and the increase in strength and porosity.[23][41][42] A 90% decrease in porosity has also been observed in MICP treated soil.[23] Light microscopic imaging suggested that the mechanical strength enhancement of cemented sandy material is caused mostly due to point-to-point contacts of calcium carbonate crystals and adjacent sand grains.[43]

One-dimensional column experiments allowed the monitoring of treatment progration by the means of change in pore fluid chemistry.[1][17][23][44] Triaxial compression tests on untreated and bio-cemented Ottawa sand have shown an increase in shear strength by a factor of 1.8.[45] Changes in pH and concentrations of urea, ammonium, calcium and calcium carbonate in pore fluid with the distance from the injection point in 5-meter column experiments have shown that bacterial activity resulted in successful hydrolysis of urea, increase in pH and precipitation of calcite.[23] However, such activity decreased as the distance from the injection point increased. Shear wave velocity measurements demonstrated that positive correlation exists between shear wave velocity and the amount of precipitated calcite.[46]

One of the first patents on ground improvement by MICP was the patent “Microbial Biocementation” by Murdoch University (Australia).[47] A large scale (100 m3) have shown a significant increase in shear wave velocity was observed during the treatment.[22] Originally MICP was tested and designed for underground applications in water saturated ground, requiring injection and production pumps. Recent work [48] has demonstrated that surface percolation or irrigation is also feasible and in fact provides more strength per amount of calcite provided because crystals form more readily at the bridging points between sand particles over which the water percolates.[49]

Benefits of MICP for liquefaction prevention

MICP has the potential to be a cost-effective and green alternative to traditional methods of stabilizing soils, such as chemical grouting, which typically involve the injection of synthetic materials into the soil. These synthetic additives are typically costly and can create environmental hazards by modifying the pH and contaminating soils and groundwater. Excluding sodium silicate, all traditional chemical additives are toxic. Soils engineered with MICP meet green construction requirements because the process exerts minimal disturbance to the soil and the environment.[41]

Possible limitations of MICP as a cementation technique

MICP treatment may be limited to deep soil due to limitations of bacterial growth and movement in subsoil. MICP may be limited to the soils containing limited amounts of fines due to the reduction in pore spaces in fine soils. Based on the size of microorganism, the applicability of biocementation is limited to GW, GP, SW, SP, ML, and organic soils.[50] Bacteria are not expected to enter through pore throats smaller than approximately 0.4 µm. In general, the microbial abundance was found to increase with the increase in particle size.[51] On the other hand, the fine particles may provide more favorable nucleation sites for calcium carbonate precipitation because the mineralogy of the grains could directly influence the thermodynamics of the precipitation reaction in the system.[21] The habitable pores and traversable pore throats were found in coarse sediments and some clayey sediments at shallow depth. In clayey soil, bacteria are capable of reorienting and moving clay particles under low confining stress (at shallow depths). However, inability to make these rearrangements under high confining stresses limits bacterial activity at larger depths. Furthermore, sediment-cell interaction may cause puncture or tensile failure of the cell membrane. Similarly, at larger depths, silt and sand particles may crush and cause a reduction in pore spaces, reducing the biological activity. Bacterial activity is also impacted by challenges such as predation, competition, pH, temperature, and nutrient availability.[52] These factors can contribute to the population decline of bacteria. Many of these limitations can be overcome through the use of MICP through bio-stimulation - a process through which indigenous ureolytic soil bacteria are enriched in situ.[52] This method is not always possible as not all indigenous soils have enough ureolytic bacteria to achieve successful MICP.[41]

Remediation for heavy metal and radionuclide contamination

MICP is a promising technique that can be used for containment of various contaminants and heavy metals. The availability of lead in soil may reduced by its chelation with the MICP product, which is the mechanism responsible for Pb immobilization.[53] MICP can be also applied to achieve sequestration of heavy metals and radionuclides. Microbially induced calcium carbonate precipitation of radionuclide and contaminant metals into calcite is a competitive co-precipitation reaction in which suitable divalent cations are incorporated into the calcite lattice.[54][55] Europium, a trivalent lanthanide, which was used as a homologue for trivalent actinides, such as Pu(III), Am(III), and Cm(III), was shown to incorporate into the calcite phase substituting for Ca(II) as well as in a low-symmetry site within the biomineral.[56]

Prevention

Shewanella oneidensis inhibits the dissolution of calcite under laboratory conditions.[57]

References
  1. Mortensen, B.M.; Haber, M.J.; DeJong, J.T.; Caslake, L.F. Nelson (2011). "Effects of environmental factors on microbial induced calcium carbonate precipitation". Journal of Applied Microbiology. 111 (2): 338–49. doi:10.1111/j.1365-2672.2011.05065.x. PMID 21624021.
  2. Ercole, C.; Cacchio, P.; Cappuccio, G.; Lepidi, A. (2001). "Deposition of calcium carbonate in karst caves: role of bacteria in Stiffe's Cave". International Journal of Speleology. 30A (1/4): 69–79. doi:10.5038/1827-806x.30.1.6.
  3. Simkiss, K (1964). "Variations in the crystalline form of calcium carbonate precipitated from artificial sea water". Nature. 201 (4918): 492–493. Bibcode:1964Natur.201..492S. doi:10.1038/201492a0.
  4. Ariyanti, D.; Handayani, N.A.; Hadiyanto (2011). "An overview of biocement production from microalgae". International Journal of Science and Engineering. 2 (2): 30–33.
  5. Castanier, S.; Le Métayer-Levrel, Gaëlle; Perthuisot, Jean-Pierre (1999). "Ca-carbonates precipitation and limestone genesis — the microbiogeologist point of view". Sedimentary Geology. 126 (1–4): 9–23. Bibcode:1999SedG..126....9C. doi:10.1016/s0037-0738(99)00028-7.
  6. Seifan, Mostafa; Berenjian, Aydin (2019-06-01). "Microbially induced calcium carbonate precipitation: a widespread phenomenon in the biological world". Applied Microbiology and Biotechnology. 103 (12): 4693–4708. doi:10.1007/s00253-019-09861-5. hdl:10289/12913. ISSN 1432-0614.
  7. Seifan, Mostafa; Samani, Ali Khajeh; Berenjian, Aydin (2016-03-01). "Bioconcrete: next generation of self-healing concrete". Applied Microbiology and Biotechnology. 100 (6): 2591–2602. doi:10.1007/s00253-016-7316-z. hdl:10289/11244. ISSN 1432-0614.
  8. Seifan, Mostafa; Sarmah, Ajit K.; Ebrahiminezhad, Alireza; Ghasemi, Younes; Samani, Ali Khajeh; Berenjian, Aydin (2018-03-01). "Bio-reinforced self-healing concrete using magnetic iron oxide nanoparticles". Applied Microbiology and Biotechnology. 102 (5): 2167–2178. doi:10.1007/s00253-018-8782-2. ISSN 1432-0614.
  9. Achal, V., Mukherjee, A., Goyal, S., Reddy, M.S. (2012). Corrosion prevention of reinforced concrete with microbial calcite precipitation. ACI Materials Journal, April, 157-163.
  10. Van Tittelboom, K.; De Belie, N.; De Muynck, W.; Verstraete, W. (2010). "Use of bacteria to repair cracks in concrete". Cement and Concrete Research. 40 (1): 157–166. doi:10.1016/j.cemconres.2009.08.025.
  11. Wiktor, V.; Jonkers, H.M. (2011). "Quantification of crack-healing in novel bacteria-based self-healing concrete". Cement and Concrete Composites. 33 (7): 763–770. doi:10.1016/j.cemconcomp.2011.03.012.
  12. Bang, S.S.; Lippert, J.J.; Mulukutla, S.; Ramakrishnan (2010). "Microbial calcite, a bio-based smart nanomaterial in concrete remediation". International Journal of Smart and Nano Materials. 1 (1): 28–39. doi:10.1080/19475411003593451.
  13. Jonkers, H.M.; Thijssena, A.; Muyzerb, G.; Copuroglua, O.; Schlangen, E. (2010). "Application of bacteria as self-healing agent for the development of sustainable concrete". Ecological Engineering. 36 (2): 230–235. doi:10.1016/j.ecoleng.2008.12.036.
  14. Ramachandran, S.K.; Ramakrishnan, V.; Bang, S.S. (2001). "Remediation of concrete using microorganisms". ACI Materials Journal. 98: 3–9. doi:10.14359/10154.
  15. De Muynck, W.; Cox, K.; De Belie, N.; Verstraete, W. (2008). "Bacterial carbonate precipitation as an alternative surface treatment for concrete". Construction and Building Materials. 22 (5): 875–885. doi:10.1016/j.conbuildmat.2006.12.011.
  16. Al-Thawadi (2011). "Ureolytic bacteria and calcium carbonate formation as a mechanism of strength enhancement of sand". Journal of Advanced Science and Engineering Research. 1: 98–114.
  17. Barkouki, T.; Martinez, B.C.; Mortensen, B.M.; Weathers, T.S.; DeJong, J.T.; Ginn, T.R.; Spycher, N.F.; Smith, R.W.; Fujita, Y. (2011). "Forward and inverse bio-mediated modeling og microbially induced calcite precipitation in half-meter column experiments". Transport in Porous Media. 90: 23–39. doi:10.1007/s11242-011-9804-z.
  18. Chou, C.-W.; Seagren, E.A.; Aydilek, A.H.; Lai, M. (2011). "Biocalcification of sand through ureolysis". Journal of Geotechnical and Geoenvironmental Engineering. 127 (12): 1179–1189. doi:10.1061/(asce)gt.1943-5606.0000532.
  19. DeJong, J.T.; Fritzges, M.B.; Nüsslein, K. (2006). "Microbial Induced Cementation to Control Sand Response to Undrained Shear". Journal of Geotechnical and Geoenvironmental Engineering. 132 (11): 1381–1392. doi:10.1061/(asce)1090-0241(2006)132:11(1381).
  20. DeJong, J.T.; Morenson, B.M.; Martinez, B.C.; Nelson, D.C. (2010). "Bio-mediated soil improvement". Ecological Engineering. 36 (2): 197–210. doi:10.1016/j.ecoleng.2008.12.029.
  21. Rong, H., Qian, C.X., Wang, R.X. (2011). A cementation method of loose particles based on microbe-based cement. Science China: Technological Sciences, 54(7), 1722-1729.
  22. Van Paassen, L.A.; Ghose, R.; van der Linden, T.J.M.; van der Star, W.R.L.; van Loosdrecht, M.C.M. (2010). "Quantifying biomediated ground improvement by ureolysis: Large-scale biogrout experiment". Journal of Geotechnical and Geoenvironmental Engineering. 136 (12): 1721–1728. doi:10.1061/(asce)gt.1943-5606.0000382.
  23. Whiffin, V.S.; van Paassen, L.A.; Harkes, M.P. (2007). "Microbial carbonate precipitation as a soil improvement technique". Geomicrobiology Journal. 24 (5): 417–423. doi:10.1080/01490450701436505.
  24. Seifan, Mostafa; Berenjian, Aydin (2018-11-01). "Application of microbially induced calcium carbonate precipitation in designing bio self-healing concrete". World Journal of Microbiology and Biotechnology. 34 (11): 168. doi:10.1007/s11274-018-2552-2. ISSN 1573-0972.
  25. Fujita, Y.; Redden, G.D.; Ingram, J.C.; Cortez, M.M.; Ferris, F.G.; Smith, R.W. (2004). "Strontium incorporation into calcite generated by bacterial ureolysis". Geochimica et Cosmochimica Acta. 68 (15): 3261–3270. Bibcode:2004GeCoA..68.3261F. doi:10.1016/j.gca.2003.12.018.
  26. Curti, E (1999). "Coprecipitation of radionuclides with calcite: Estimation of partition coefficients based on a review of laboratory investigations and geochemical data". Applied Geochemistry. 14 (4): 433–445. Bibcode:1999ApGC...14..433C. doi:10.1016/s0883-2927(98)00065-1.
  27. Zachara, J.M.; Cowan, C.E.; Resch, C.T. (1991). "Sorption of divalent metals on calcite". Geochimica et Cosmochimica Acta. 55 (6): 1549–1562. Bibcode:1991GeCoA..55.1549Z. doi:10.1016/0016-7037(91)90127-q.
  28. Pingitore, N.E.; Eastman, M.P. (1986). "The coprecipitation of Sr2+ and calcite at 25°C and 1 atm". Geochimica et Cosmochimica Acta. 50 (10): 2195–2203. doi:10.1016/0016-7037(86)90074-8.
  29. Khodadadi Tirkolaei, H.; Kavazanjian, E.; van Paassen, L.; DeJong, J. (2017). "Bio-Grout Materials: A Review". Biogrout Materials: A Review. pp. 1–12. doi:10.1061/9780784480793.001. ISBN 9780784480793.
  30. Riding, E.; Awramik, S.M., eds. (2000). Microbial Sediments.
  31. Monty, C.L.V., Bosence, D.W.J, Bridges, P.H., Pratt, B.R. (eds.)(1995). Carbonate Mud-Mounds: Their Origin and Evolution. Wiley-Blackwell
  32. Hammes, F.; Seka, A.; de Knijf, S.; Verstraete, W. (2003). "A novel approach to calcium removal from calcium-rich industrial wastewater". Water Research. 37 (3): 699–704. doi:10.1016/s0043-1354(02)00308-1. PMID 12688705.
  33. Seifan, Mostafa; Samani, Ali Khajeh; Berenjian, Aydin (2017-04-01). "New insights into the role of pH and aeration in the bacterial production of calcium carbonate (CaCO3)". Applied Microbiology and Biotechnology. 101 (8): 3131–3142. doi:10.1007/s00253-017-8109-8. hdl:10289/11243. ISSN 1432-0614. PMID 28091788.
  34. Jagadeesha Kumar, B.G.; Prabhakara, R.; Pushpa, H. (2013). "Bio mineralization of calcium carbonate by different bacterial strains and their application in concrete crack remediation". International Journal of Advances in Engineering & Technology. 6 (1): 202–213.
  35. Achal, V.; Mukherjee, A.; Basu, P.C.; Reddy, M.S. (2009). "Strain improvement of Sporosarcina pasteurii for enhanced urease and calcite production". Journal of Industrial Microbiology and Biotechnology. 36 (7): 981–988. doi:10.1007/s10295-009-0578-z. PMID 19408027.
  36. Wang, J. (2013). Self-healing concrete by means of immobilized carbonate precipitating bacteria. Ghent University. Faculty of Engineering and Architecture, Ghent, Belgium
  37. De Muynck, W.; Debrouwer, D.; Belie, N.; Verstraete, W. (2008). "Bacterial carbonate precipitation improves durability of cementitious materials". Cement and Concrete Research. 38 (7): 1005–1014. doi:10.1016/j.cemconres.2008.03.005.
  38. Reddy, S.; Achyutha Satya, K.; Seshagiri Rao, M.V.; Azmatunnisa, M. (2012). "A biological approach to enhance strength and durability in concrete structures". International Journal of Advances in Engineering & Technology. 4 (2): 392–399.
  39. Suzanne LaBarre (May 1, 2010). "The Better Brick: 2010 Next Generation Winner". Metropolis Magazine.
  40. Yoshida, N.; Higashimura, E.; Saeki, Y. (2010). "Catalytic biomineralization of fluorescent calcite by the thermophilic bacterium Geobacillus thermoglucosidasius". Applied and Environmental Microbiology. 76 (21): 7322–7327. doi:10.1128/aem.01767-10. PMC 2976237. PMID 20851984.
  41. Soon, Ng Wei; Lee, Lee Min; Khun, Tan Chew; Ling, Hii Siew (2014-01-13). "Factors Affecting Improvement in Engineering Properties of Residual Soil through Microbial-Induced Calcite Precipitation". Journal of Geotechnical and Geoenvironmental Engineering. 140 (5): 04014006. doi:10.1061/(asce)gt.1943-5606.0001089.
  42. Lee, Min Lee; Ng, Wei Soon; Tanaka, Yasuo (2013-11-01). "Stress-deformation and compressibility responses of bio-mediated residual soils". Ecological Engineering. 60: 142–149. doi:10.1016/j.ecoleng.2013.07.034.
  43. Al-Thawadi (2008). High strength in-situ biocementation of soil by calcite precipitating locally isolated ureolytic bacteria (Ph.D. dissertation). Murdoch University, Western Australia.
  44. Al Qabany, Ahmed; Soga, Kenichi; Santamarina, Carlos (August 2012). "Factors affecting efficiency of microbially induced calcite precipitation". Journal of Geotechnical and Geoenvironmental Engineering. 138 (8): 992–1001. doi:10.1061/(ASCE)GT.1943-5606.0000666.
  45. Tagliaferri, F.; Waller, J.; Ando, E.; Hall, S.A.; Viggiani, G.; Besuelle, P.; DeJong, J.T. (2011). "Observing strain localization processes in bio-cemented sand using X-ray imaging" (PDF). Granular Matter. 13 (3): 247–250. doi:10.1007/s10035-011-0257-4.
  46. Weil, M.H., DeJong, J.T., Martinez, B.C., Mortensen, B.M., Waller, J.T. (2012). Seismic and resistivity measurements for real-time monitoring of microbially induced calcite precipitation in sand. ASTM J. Geotech. Testing, In Press.
  47. Kucharski, E.S., Cord-Ruwisch, R., Whiffin, V.S., Al-Thawadi, S.M.J. (2006). Microbial biocementation, World Patent. WO/2006/066326, June. 29.
  48. Cheng, L.; Cord-Ruwisch, R. (2012). "In situ soil cementation with ureolytic bacteria by surface percolation". Ecological Engineering. 42: 64–72. doi:10.1016/j.ecoleng.2012.01.013.
  49. Cheng, L.; Cord-Ruwisch, R.; Shahin, M.A. (2013). "Cementation of sand soil by microbially induced calcite precipitation at various degrees of saturation". Canadian Geotechnical Journal. 50 (1): 81–90. doi:10.1139/cgj-2012-0023. hdl:20.500.11937/33429.
  50. Mitchell, J.K.; Santamarina, J.C. (2005). "Biological considerations in geotechnical engineering". Journal of Geotechnical and Geoenvironmental Engineering. 131 (10): 1222–1233. doi:10.1061/(asce)1090-0241(2005)131:10(1222).
  51. Rebata-Landa, V.; Santamarina, J.C. (2006). "Mechanical limits to microbial activity in deep sediments". Geochemistry, Geophysics, Geosystems. 7 (11): 1–12. Bibcode:2006GGG.....711006R. CiteSeerX 10.1.1.652.6863. doi:10.1029/2006gc001355.
  52. Burbank, Malcolm; Weaver, Thomas; Williams, Barbara; Crawford, Ronald (June 2013). "Geotechnical Tests of Sands Following Bioinduced Calcite Precipitation Catalyzed by Indigenous Bacteria". Journal of Geotechnical and Geoenvironmental Engineering. 139 (6): 928–936. doi:10.1061/(ASCE)GT.1943-5606.0000781.
  53. Achal, Varenyam; Pan, Xiangliang; Zhang, Daoyong; Fu, Qinglong (2012). "Bioremediation of Pb-contaminated soil based on microbially induced calcite precipitation". Journal of Microbiology and Biotechnology. 22 (2): 244–247. doi:10.4014/jmb.1108.08033. PMID 22370357.
  54. Hamdan, N., Kavazanjian, Jr. E., Rittmann, B.E. (2011). Sequestration of radionuclides and metal contaminants through microbially-induced carbonate precipitation. Pan-Am CGS Geotechnical Conference
  55. Li, L.; Qian, C.X.; Cheng, L.; Wang, R.X. (2010). "A laboratory investigation of microbe-inducing CdCO3 precipitate treatment in Cd2+ contaminated soil". Journal of Soils and Sediments. 10 (2): 248–254. doi:10.1007/s11368-009-0089-6.
  56. Johnstone, Erik; Hofmann, Sascha; Cherkouk, Andrea; Schmidt, Moritz (2016). "Study of the interaction of Eu3+ with Microbially Induced Calcium Carbonate Precipitates Using TRLFS". Environmental Science and Technology. 50 (22): 12411–12420. doi:10.1021/acs.est.6b03434. PMID 27766852.
  57. Andrea Rinaldi (November 7, 2006). "Saving a fragile legacy. Biotechnology and microbiology are increasingly used to preserve and restore the world's cultural heritage". EMBO Reports. 7 (11): 1075–1079. doi:10.1038/sj.embor.7400844. PMC 1679785. PMID 17077862.
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