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Original - "Bioremediation"

Genetic engineering approaches

The use of genetic engineering to create organisms specifically designed for bioremediation has great potential.[1] The bacterium Deinococcus radiodurans (the most radioresistant organism known) has been modified to consume and digest toluene and ionic mercury from highly radioactive nuclear waste.[2] Releasing genetically augmented organisms into the environment may be problematic as tracking them can be difficult; bioluminescence genes from other species may be inserted to make this easier.[3] : 135 

  1. ^ Lovley, DR (2003). "Cleaning up with genomics: applying molecular biology to bioremediation". Nature Reviews Microbiology. 1 (1): 35–44. doi:10.1038/nrmicro731. PMID 15040178.
  2. ^ Brim H, McFarlan SC, Fredrickson JK, Minton KW, Zhai M, Wackett LP, Daly MJ (2000). "Engineering Deinococcus radiodurans for metal remediation in radioactive mixed waste environments". Nature Biotechnology. 18 (1): 85–90. doi:10.1038/71986. PMID 10625398.
  3. ^ Robert L. Irvine; Subhas K. Sikdar. Bioremediation Technologies: Principles and Practice.

Edit - "Bioremediation"

Aerobic bioremediation

Aerobic bioremediation is the biodegradation of many organic contaminants into carbon dioxide, water, and cell mass by microorganisms in the presence of oxygen[1][2]. Under anoxic conditions, nitrate may be used as an alternative electron acceptor[3]. These microorganisms use oxygen as an electron acceptor and the contaminants as their only source of carbon and energy[4]. For example, in the degradation of hydrocarbons, oxygen would be the electron acceptor and the hydrocarbons would provide carbon and energy[2]. Noted microorganisms that biodegrade under aerobic conditions are Pseudomonas, Alcaligenes, Sphingomonas, Rhodococcus, and Mycobacterium. These bacteria degrade pesticides and hydrocarbons[4]. For hydrocarbon-degrading bacteria, oxygen is a primary limiting factor for growth because oxygen is normally depleted in zones contaminated with hydrocarbons[2]. Enhanced bioremediation or oxygen enhancement is the increase in oxygen levels to increase the rate of biodegradation[2][3]. Some technologies used to increase the oxygen content are bioventing and biosparging. Bioventing is injecting air or oxygen into unsaturated soil. Biosparging is injecting air or oxygen into groundwater or saturated soil[5][2]. Biosparging is usually used in conjunction with bioventing[3]. Sometimes, hydrogen peroxide or magnesium peroxide may be added to increase the oxygen level in soil[4][3]. It is important to note that in addition to injecting oxygen into contaminated zones, appropriate nutrients may be added to enhance microbial activity[4][3]. Types of contaminants that are cleaned up using aerobic bioremediation include "BTEX" (benzene, toluene, ethylbenzene, and xylene), PAHs (polyaromatic hydrocarbons), and pesticides[4]. Lastly, aerobic bioremediation is important as many bioremediation systems are run under aerobic conditions, however, anaerobic bioremediation is important in the biodegradation of some recalcitrant pollutants[4].

Genetic engineering approaches

The use of genetic engineering to create organisms specifically designed for bioremediation has great potential.[6] The bacterium Deinococcus radiodurans (the most radioresistant organism known) has been modified to consume and digest toluene and ionic mercury from highly radioactive nuclear waste.[7] Releasing genetically augmented organisms into the environment may be problematic as tracking them can be difficult; bioluminescence genes from other species may be inserted to make this easier.[8] : 135 

  1. ^ "4.2 Enhanced Bioremediation (In Situ Soil Remediation Technology)". frtr.gov.
  2. ^ a b c d e "Bioremediation Aerobic Bioremediation (Direct)". clu-in.org.
  3. ^ a b c d e "4.29 Enhanced Bioremediation (In Situ GW Remediation Technology)". frtr.gov.
  4. ^ a b c d e f Vidali, M. "Bioremediation. An overview*" (PDF). www.iupac.org. Pure and Applied Chemistry.
  5. ^ Juwarkar, Asha A.; Singh, Sanjeev K.; Mudhoo, Ackmez (1 September 2010). "A comprehensive overview of elements in bioremediation". Reviews in Environmental Science and Bio/Technology. pp. 215–288. doi:10.1007/s11157-010-9215-6.
  6. ^ Lovley, DR (2003). "Cleaning up with genomics: applying molecular biology to bioremediation". Nature Reviews Microbiology. 1 (1): 35–44. doi:10.1038/nrmicro731. PMID 15040178.
  7. ^ Brim H, McFarlan SC, Fredrickson JK, Minton KW, Zhai M, Wackett LP, Daly MJ (2000). "Engineering Deinococcus radiodurans for metal remediation in radioactive mixed waste environments". Nature Biotechnology. 18 (1): 85–90. doi:10.1038/71986. PMID 10625398.
  8. ^ Robert L. Irvine; Subhas K. Sikdar. Bioremediation Technologies: Principles and Practice.


Lizhuang97 (talk) 23:53, 7 October 2017 (UTC)

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