Microbes pollution degradation

Bartha, R. Biotechnology of petroleum pollutant degradation. Microb. Ecol. 1986, 12, 155-172. 

Biocatalytic membrane processes are not mutually exclusive rather, they can be coupled into one membrane reactor to obtain added advantages. However, to date only a limited number of studies have tapped this potential. For instance, Hai et al. (2011) envisaged that modihcation of membrane modules to dynamically immobilize pollutant degrading enzymes on membranes within a whole-cell MBR may bring about the added advantages of continuous enzyme production (by microbes) and prevention of washout of enzyme. The resultant continuous application of enzyme, minimizing washout, may mean undisrupted operation even under conditions where dena-turation of enzyme would occur over time. 

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. 

Lee RF, Ryan C. 1979. Microbial degradation of organochlorine compounds in estuarine waters and sediments. In Proceedings Workshop Microb Degradation Pollut Mar Environ, 1978. Washington, DC U.S. EPA, Office of Research and Development. EPA 600/9-79-012. 

Environmental contamination usually consists of a mixture of pollutants and their partially degraded derivatives. Such an ill-defined chemical mixture will eventually lead to the formation of an ecosystem of microbes. The individual member species cannot survive in the toxic and hostile environment. Effective bioremediation technologies should therefore invoke a mixture of microorganisms forming synergistic consortia. Any realistic bioremediation concept is based on the recognition that it is the concerted action of various species, which may bring about the desired clean-up effect. 

Gardner, W. S., Lee, R. F., Tenore, K. R. Smith, L. W. (1979). Degradation of selected polycyclic aromatic hydrocarbons in coastal sediments importance of microbes and polychaete worms. Water, Air, and Soil Pollution, 11, 339—47. 

The phytoremediation process may be viewed as a symbiotic process between plants and soil microbes that involved in phytoremediation (Lasat, 2002). Plant and bacterial interaction can enhance the effectiveness of phytoremediation technology because plants provide carbon and energy sources or root exudates in the rhizosphere that will support microbial community in the degradation and transformation of soil pollutants (Siciliano and Germida, 1998). In addition, the presence of soil microbes can increase the water solubility or bioavailability of pollutants in soils, which facilitates the uptake of pollutants by plants (Lasat, 2002 Siciliano and Germida, 1998). However, the specificity of the plant-bacteria interactions besides being much intricate is dependent upon soil and the aqueous conditions, which can alter contaminant... 

Aust SD. 1990. Degradation of environmental pollutants by Phanerochaete chrysoporium. Microb Ecol 20 197-209. 

Low bioavailability of hydrocarbon pollutants can limit the biodegradation by indigenous micro-communities in soils. CDs enhance desorption of the nonpolar contaminants from the solid surface and transfer them to the water-phase biofilms, where the hydrocarbon-degrading microbes work. Therefore, this special character of CDs and their derivatives can be used for enhanced removal of hydrocarbon contaminants from soil [92]. This is so-called CD-enhanced pump and treat technology for the removal of dense, non-aqueous phase liquid from the saturated soil. For example, HP- -CD solution was added into the source zone... 

With the advent of the chemical industry, this picture has changed dramatically. In polluted locations, microorganisms may be confronted with a large number of solvents at high concentrations. With a few exceptions only, it has turned out that microbes can be found that are able to degrade these compounds if their concentration is low. This degradative potential is not unexpected in view of trace amounts that may be present locally in the natural biosphere. But the exposure of cells to unnatural high concentrations of these solvents usually leads to irreversible inactivation and finally to their death. 

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