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Original - "Bioremediation"
Additives
[edit]In some cases, nitrogen, phosphorus, micronutrients, vitamins, and other materials are added to improve conditions for microbial respiration.[citation needed]
Many biological processes are sensitive to pH and function most efficiently in near neutral conditions.[1] Low pH can interfere with pH homeostasis or increase the solubility of toxic metals.[2] Microorganisms can expend cellular energy to maintain homeostasis or cytoplasmic conditions may change in response to external changes in pH.[3] Some anaerobes have adapted to low pH conditions through alterations in carbon and electron flow, cellular morphology, membrane structure, and protein synthesis.[1]
- ^ a b Lowe, SE; Jain, MK; Zeikus, JG (June 1993). "Biology, ecology, and biotechnological applications of anaerobic bacteria adapted to environmental stresses in temperature, pH, salinity, or substrates". Microbiological reviews. 57 (2): 451–509. PMC 372919. PMID 8336675.
- ^ Slonczewski, J.L. (2009). "Stress Responses: pH". In Schaechter, Moselio (ed.). Encyclopedia of microbiology (3rd ed. ed.). Elsevier. pp. 477–484. doi:10.1016/B978-012373944-5.00100-0. ISBN 978-0-12-373944-5.
{{cite book}}:|edition=has extra text (help) - ^ Foster, JW (April 1999). "When protons attack: microbial strategies of acid adaptation". Current opinion in microbiology. 2 (2): 170–4. doi:10.1016/S1369-5274(99)80030-7. PMID 10322170.
Edit - "Bioremediation"
Additives
[edit]In some cases, nitrogen, phosphorus, micronutrients, vitamins, and other materials are added to improve conditions for microbial respiration.[citation needed]
Many biological processes are sensitive to pH and function most efficiently in near neutral conditions.[1] Low pH can interfere with pH homeostasis or increase the solubility of toxic metals.[2] Microorganisms can expend cellular energy to maintain homeostasis or cytoplasmic conditions may change in response to external changes in pH.[3] Some anaerobes have adapted to low pH conditions through alterations in carbon and electron flow, cellular morphology, membrane structure, and protein synthesis.[1]
Limitations
[edit]Only biodegradable contaminants can be transformed using bioremediation processes.[4] Some compounds, such as highly chlorinated compounds, heavy metals, and radionuclides are not readily biodegradable.[5][6][7] Also, microbes sometimes do not fully biodegrade a pollutant and may end up producing a more toxic compound.[7] For example, under anaerobic conditions, the reductive dehalogenation of TCE may produce vinyl chloride which is a known carcinogen.[5] Therefore, more research is required to see if the products from biodegradation are less persistent and less toxic than the original contaminant.[7] Thus, the metabolic and chemical pathways of the microorganisms of interest must be known.[5] In addition, knowing these pathways will help develop new technologies that can deal with sites that have uneven distributions of a mixture of contaminants.[4]
Also, for biodegradation to occur, there must be a microbial population with the metabolic capacity to degrade the pollutant, an environment with the right growing conditions for the microbes, and the right amount of nutrients and contaminants.[4][6] The biological processes used by these microbes are highly specific, therefore, many environmental factors must be taken into account and regulated as well.[4][5] Thus, bioremediation processes must be specifically made in accordance to the conditions at the contaminated site.[5] Also, because many factors are interdependent, small-scale tests must be performed before carrying out the procedure at the contaminated site.[6] However, it is difficult to extrapolate the results from the small-scale test studies into big field operations.[4] Lastly, the process of bioremediation is longer and can be more expensive than other conventional options such as land filling and incineration.[4][5]
- ^ a b Lowe, SE; Jain, MK; Zeikus, JG (June 1993). "Biology, ecology, and biotechnological applications of anaerobic bacteria adapted to environmental stresses in temperature, pH, salinity, or substrates". Microbiological reviews. 57 (2): 451–509. PMC 372919. PMID 8336675.
- ^ Slonczewski, J.L. (2009). "Stress Responses: pH". In Schaechter, Moselio (ed.). Encyclopedia of microbiology (3rd ed. ed.). Elsevier. pp. 477–484. doi:10.1016/B978-012373944-5.00100-0. ISBN 978-0-12-373944-5.
{{cite book}}:|edition=has extra text (help) - ^ Foster, JW (April 1999). "When protons attack: microbial strategies of acid adaptation". Current opinion in microbiology. 2 (2): 170–4. doi:10.1016/S1369-5274(99)80030-7. PMID 10322170.
- ^ a b c d e f Vidali, M. "Bioremediation. An overview*" (PDF). IUPAC. Pure and Applied Chemistry.
- ^ a b c d e f 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.
- ^ a b c Boopathy, R (1 August 2000). "Factors limiting bioremediation technologies". Bioresource Technology. pp. 63–67. doi:10.1016/S0960-8524(99)00144-3.
- ^ a b c Wexler, editor-in-chief, Philip (2014). Encyclopedia of toxicology (3rd ed. ed.). San Diego, Ca: Academic Press Inc. p. 489. ISBN 9780123864543.
{{cite book}}:|edition=has extra text (help);|first1=has generic name (help)CS1 maint: multiple names: authors list (link)
Lizhuang97 (talk) 00:51, 20 November 2017 (UTC)