Genetic Engineering for Human Welfare

Abatement of Pollution through Genetically Engineered Microorganisms

For detoxification and degradation of toxic chemicals, enzymes are encoded by specific genes present on plasmids. Chakraborty and coworkers (1979) succeeded in isolating the microbial culture which could utilize a number of organic chemicals, toxic in nature, such as salicylate, 2,4-D, 3 chlorobenzenes, ethylene, biphenyls, 1,2,4-trimethylbenzene, 2, 4, 5-trichlorophenoxy-acetic acid, etc. (Chatterjee et al, 1981; Kellogg et al., 1981).

  Creation of a superbug (Diagrammatic).  
 

Fig. 5.12. Creation of a superbug (Diagrammatic).

 

Genes responsible for degradation of environmental pollutants, for example, toluene, chlorobenzene acids, and other halogenated pesticides and toxic wastes have been identified. For every compound, one separate plasmid is required. It is not like that one plasmid can degrade all the toxic compounds of different groups. The plasmids are grouped into four categories:
(i)
OCT plasmid which degrades, octane, hexane and decane,
(ii)
XYL plasmid which degrades xylene and toluenes,
(iii)
CAM plasmid that decompose camphor, and
(iv)
NAH plasmid which degrades naphthalene.
Dr Anand Mohan Chakrabarty (an Indian borne American scientist) produced a new product of genetic engineering called as superbug (oil eating bug) by introducing plasmids from different strains into a single cell of P. putida. This superbug is such that can degrade all the four types of substrates for which four separate plasmids were required (Fig 5.12).

The plasmids of P. putida degrading various chemical compounds are TOL (for toluene and xylene), RA500 (for 3,5-xylene) pAC 25 (for 3-cne chlorobenxoate), pKF439 (for salicylatetoluene). Plasmid WWO of P. putida is one member of a set of plasmids now termed as TOL plasmid. WWO is propagated in E. coli (Chatterjee et al, 1981; Kellogg et al 1981).
For a detail discussion see Environmental Biotechnology .


  Content
» Cloned genes and production of chemicals

» Human peptide hormone genes


» Insulines


» Somatotropin


» Somatostatin


» b-endorphin

» Human interferon genes

» Genes for vaccines


» Vaccine for hepatitis-B virus


» Vaccines for Rabies virus


» Vaccines for poliovirus


» Vaccine for foot and mouth disease virus


» Vaccines for small pox virus


» Malaria vaccines


» DNA vaccines

» Genes associated with genetic diseases


» Phenylketonuria


» Urokinase


» Thalassaemia


» Hemophilia

» Enzyme engineering

» Commercial chemicals
» Prevention, diagnosis and cure of diseases

» Prevention of diseases

» Diagnosis of diseases


» Parasitic diseases


» Monoclonal antibodies


» Antenatal diagnosis

» Gene therapy


» Types of gene therapy


» Methods of gene therapy


» Success of gene therapy


» Potential of gene delivering system


» Future needs of gene therapy in India
» DNA profiling (fingerprinting)

» Methods of DNA profiling

» Application of DNA profiling


» Genetic databank


» Reuniting the lost children


» Solving disputed problems of parentage, identity of criminals, rapists, etc


» Immigrant dispute

» Hurdles of DNA profiling
» Animal and plant improvement

» Transgenic Farm Animals

» Crop Improvements


» Transgenic plants


» Nif gene transfer


» Phaseolin gene transfer


» Conversion of C3 plants to C4 plants


» Herbicide resistant plants


» Insect pest resistant plants


» Plant improvement through genetic transformation

» Crop Protection


» Use of antagonists


» Use of insecticides
» Abatement of pollution