Author_Institution :
Dept. of Cellular & Mol. Biol., Imam Hossein Univ. of Tehran, Tehran, Iran
Abstract :
Environmental pollutants have become a major global concern. The waste generated from the development of products and processes are of concern to the environmentalist. One of the major issues in recent times is the threat to the human life caused due to the progressive deterioration of the environment. The waste generated from the development of products and processes are of concern to the environmentalist. Heavy metals are also reported persisting into the environment causing toxicity to living organisms through bioaccumulation, adsorption and biotransformation. A number of microorganisms, as a result of their versatility, adaptability and diversity in the environment, are considered to be the best candidates among all living organisms to remediate most of the environmental contaminants into the natural biogeochemical cycle. These natural forces of biodegradation can reduce waste and cleanup some types of environmental contaminants. Compositing can accelerate natural biodegradation and convert organic wastes to valuable resources. Deinococcus radiodurans is known as the world´s toughest bacteria and it is the most radiation resistant organism known. Scientists are interested in this organism because of its potential usefulness in cleaning up waste sites that contain radiation and toxic chemicals. It can tolerate radiation levels at 1000 times the levels that would kill a human and it was originally isolated in 1956 from a can of meat that had been irradiated with X-rays. The bacterium can tolerate high levels of chemical, oxidative, UV, and ionizing radiation-induced damage to the cell´s DNA, which it efficiently repairs. The resistance to radiation may reflect its resistance to dessication, which also causes DNA damage. This organism may be of use in cleaning up toxic metals found at nuclear weapons production sites due to the radiation resistance. Deinococcus has been genetically engineered for use in bioremediation to consume and digest solvents and heavy meta- ls, even in a highly radioactive site. For example, the bacterial mercuric reductase gene has been cloned from Escherichia coli into Deinococcus to detoxify the ionic mercury residue frequently found in radioactive waste generated from nuclear weapons manufacture. This bacterium is also a highly efficient transformer, and can readily take up exogenous DNA from the environment, which may also aid DNA repair. Bioinformatics offers many interesting possibilities for bioremediation from environment protection point of view. Genomic and bioinformatic data provide a wealth of information that would be greatly enhanced by structural characterisation of some of these proteins in them. It can be extended to follow the leads provided by collaborating bioinformatics experts and proteomics studies. This may ultimately result not only in a more complete understanding of the radiation resistance of this bacterium, but also to the discovery of novel DNA repair systems, applicable to an understanding of the mechanisms of higher organisms such as man. Analysis of paralogs in Deinococcus has revealed several unique protein families. In addition, specific expansions of several other families including phosphatases, proteases, acyltransferases, and Nudix family pyrophosphohydrolases were detected. Genes that potentially affect DNA repair and stress responses and recombination were investigated in this article. These observations suggest that several different biological mechanisms contribute to the multiple DNA repair-dependent phenotypes of this organism. Then D.radiodurans as a bioremediation agent, can remove heavy metals and organic solvents such that the subsequent radionuclide isolation is safer and easier. This analysis is a single substantiation of function of Nudix protein family with is taken from D.radiodurans R1, for the purpose of waste clean up.
Keywords :
bioinformatics; environmental science computing; DNA repair system; Deinococcus radioduran; Nudix family pyrophosphohydrolases; acyltransferases; bioaccumulation; bioinformatics analyses; bioremediation; bioremediation agent; biotransformation; environment progressive deterioration; environmental pollutant; heavy metal; multiple DNA repair dependent phenotypes; phosphatases; proteases; radiation resistance; radiation resistant organism; radionuclide isolation; waste clean up; Biodegradation; Bioinformatics; Cleaning; DNA; Humans; Immune system; Microorganisms; Nuclear weapons; Organisms; Proteins; Waste clean up; biodegradation; genomics and bioinformatics; proteomics;