Pollution bioremediation

Biodegradation depends on the microbial production of enzymes capable of catalyzing chemical reactions that will transform (or, ideally, mineralize) pollutants. Bioremediation technologies can be enhanced in several ways, but the existing biochemical capabilities of the organisms should be reviewed before any anticipated genetic alterations are considered. 

Koren, O., Knezevic, V., Ron, E.Z., and Rosenberg, E. 2003. Petroleum pollution bioremediation using water-insoluble uric acid as the nitrogen source. Applied Environmental Microbiology, 69 6337-39. 

Intra-scene LST values are directly proportional to pollution intensity. The higher temperatures in the LST maps indicate relatively higher pollntion. It is clear from Figs. 15-18 that the intensity of pollution and spatial extent has reduced in successive years. This decrease is probably due to several reasons increase in depth of pollutants bioremediation sludge recovery leaching and chemical alterations. 

Bioremediation has many advantages over other technologies, both in cost and in effectively destroying or extracting the pollutant. An important issue is thus when to consider it, and a series of questions may lead to the appropriate answer (see Table 4). 

The refractory nature of some pollutants, notably, persistent polyhalogenated compounds, has raised problems of bioremediation of contaminated sites (e.g., sediments and dumping sites). There has been interest in the identification, or the production by genetic manipulation, of strains of microorganisms that can metabolically degrade recalcitrant molecules. For example, there are bacterial strains that can reductively dechlorinate PCBs under anaerobic conditions. 

At present, photosynthetic organisms are not generally used as biocatalysts for bioconversion of organic compounds except for bioremediation of pollutants in the environment, although they are environment-friendly catalysts, and they may contain unusual type of enzymes to establish new reactions. Development of bioreactors specially developed for photosynthefic organism-catalyzed reaction as well as finding effective photosynthetic organisms as a biocatalyst are required in the future. 

Dott W, D Eeidieker, M Steiof, PM Beckerm, P Kampfer (1995) Comparison of ex situ and in situ techniques for bioremediation of hydrocarbon-polluted soils. Int Biodet Biodeg 35 301-316. 

Atlas RM (1995) Bioremediation of petroleum pollutants. IntBiodet Biodeg 35 317-327. 

Wilson SS, KC Jones (1993) Bioremediation of soil contaminated with polynuclear aromatic hydrocarbons PAHs, a review. Environ Pollut 81 229-249. 

A further application of the manipulation of microbial activity in the rhizo-sphere is their potential to remediate contaminated land. Bioremediation involves the u.se of microorganisms that break down contaminants. Radwan et al. (255) found that the soil associated with the roots of plants grown in soil heavily contaminated with oil in Kuwait was free of oil residues, presumably as a result of the ability of the resident rhizosphere microflora to degrade hydrocarbons. The use of plants as a means to accumulate pollutants such as heavy metals (256,257) to degrade hydrocarbons and pesticides (255) is already widely implemented and has proven to be successful. In some cases, there is no doubt that it is the plant itself that is responsible for the removal of the contaminants. However, in most... 

Regardless of whether the microbes are native or artificially introduced into the soil, it is important to understand the mechanisms by which they degrade or detoxify hazardous pollutants through their metabolic activity. Understanding these mechanisms is essential for the proper design of bioremediation systems that provide the optimum conditions and the required nutritional supplements for the specific microbial process. 

Successful bioremediation requires microbes and suitable environmental factors for degradation to occur. The most suitable microbes are bacteria or fungi that have the physiological and metabolic capabilities to degrade the pollutants. 

This section focuses on engineered in situ remediation technologies that use microorganisms to biodegrade pollutant chemicals. In situ bioremediation technologies are configured to either directly... 

Although the use of mediator compounds is scarcely applicable in deca-BDE in situ bioremediation processes, it is important to consider whether their presence enhances the degradation of the pollutant by the enzyme laccase because it is known that the fungus is able to produce naturally certain compounds that can act as mediators in pollutant degradation by laccase and this study would show the extent of their effect on deca-BDE degradation in case that laccase was involved. 

Srinath T, Verma T, Ramteke PW, Garg SK (2002) Chromium biosorption and bioaccumulation by chromate resistant bacteria. Chemosphere 48 427-435 Stephen JR, Macnaughton SJ (1999) Developments in terrestrial bacterial remediation of metals. Curr Opinion Biotechnol 10 230-233 Tabak HH, Lens P, van Hullebusch ED, Dejonghe W (2005) Developments in bioremediation of soils and sediments polluted with metals and radionuclides 1. Microbial processes and mechanisms affecting bioremediation of metal contamination and influencing metal toxicity and transport. Rev Environ Sci Bio/Technol. 4 115-156... 

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