Super bug
- 1. MICROBIAL BIOTECHNOLOGY Genetically Engineered Microorganism (Super bug) Presentation by: A.Abinaya Kalyani 15SUMB01 III B.Sc Microbilogy
- 2. Genetically Engineered Microorganism : An organism whose genetic characteristics have been altered by the insertion of a modified gene or a gene from another organism using the techniques of Genetic Engineering.
- 3. Super bug : ‘Superbug’ is a constructed bacterium, Pseudomonas putida that can degrade hydrocarbons found in petroleum wastes. It is a multiplasmid strain developed by using genetic engineering technique. Pseudomonas putida
- 4. Super bug was developed by Anand Chakrabarty et al. in 1979. It is used to treat oil spills as a measure to control oil pollution. Petroleum products contain cycloalkenes(octane), napthenes, xylene, tolune and aromatic hydrocarbons. Since these compounds are not easily biodegradable, oil wastes become a major pollutant on the soil and water. Chakrabarty et al. took attempts to degrade oil wastes using micro organisms. They developed superbug to control oil pollution. Anand Chakrabarty
- 5. Construction of Superbug : The construction of superbug involves the following steps : Identification of parent strains Conjugative transfer of plasmids Selection of superbug Mass culture
- 6. Strains CAM plasmid OCT plasmid XYL plasmid NAH plasmid Isolation and characterization of parent strains Isolatian step followed by selection
- 7. Identification of parent strains : Chakrabarty et al. had succeeded in isolating different strains of P.putida that could degrade camphor,octane,xylene and napthenes from polluted soils. They found out that each strain has a special type of plasmid. Thus four types of plasmids are recognized in the bacterial strains. They are:- 1.CAM plasmid 2.OCT plasmid 3.XYL plasmid 4.NAH plasmid The bacterial strain containing CAM plasmid could degrade camphor compounds. Those strain containing OCT plasmid could degrade octane,hexane and decane. The strain containing XYL plasmid could degrade xylene and toluene. And the strain harbouring NAH plasmid could degrade napthenes.
- 8. Conjugative Transfer of plasmids : The strain A containing CAM plasmid is mated with strain B containing OCT plasmid. During this process, CAM plasmid is transferred from strain A to B. Inside the bacterial strain B, CAM plasmid undergo homologous recombination, so that a large CAM-OCT plasmid is formed. Thus the strain B becomes strain E. The strain C containing XYL plasmid is mated with strain D containing NAH plasmid. During this conjugation XYL of strain C enters the strain D. Thus strain D becomes strain F containing both XYL and NAH plasmids.
- 9. The strain E and strain F are mated to transfer CAM-OCT plasmid into the strain F. Because of the plasmid transfer, strain F becomes strain G. The strain G has three plasmids, namely CAM-OCT plasmid, XYL plasmid and NAH plasmid. It can degrade camphor, octane, xylene and naphthenes. It is named as superbug because of its high metabolic capabilities. Mixture of Pseudomonas strains Colonies of superbug Subculture Mixture+camphor, octane,xylene& napthene
- 10. Selection of Superbug: Because of repeated mating, the Pseudomonas culture has strain A, strain B, strain C ,strain D, strain E, strain F and strain G (Super bug). From this mixture of strains, strain G is selected by culturing the strains in the presence of all the four pollutants, namely camphor, octane,xylene and napthenes. The superbug alone can grow in the medium. It is subcultured in fresh medium lacking the pollutants for future use.
- 12. Mass culture of Superbug: The selected colonies of superbug is mass cultured in a suitable liquid medium in a large bioreactor for mass production. Pseudomonas putida on Blood agar plate
- 13. Application of Superbug : A patent was given to Chakrabarty regarding the construction and use of superbug. The American Government, in 1990, allowed to use the superbug to clean up oil spills in the water of Texas state. The mass culture of superbug is sprinkled over paddy straw and the straw is dried in shade. The bacteria inoculated straw can be stored for more than an year until we are in need. To treat oil spill, the straw is spread over the oil slicks and is left as such for a week or more. During this time, the straw soak up the oil and the bacteria living on it break the oil into non-polluting materials. As a result, the oil wastes become harmless to other organisms living on soil or water polluted with petroleum oil.
- 14. Superbug culture Mixing with paddy straw Drying Spreading on oil slicks Microbial degradation of oil wastes Flow chart showing stages in the use of superbug in the treatment of oil wastes
- 15. THANK YOU…!