Microbiology Notes | Biochemistry,Immunolgy,Cell biology

What Is Xenobiotic Compound? Xenobiotic compounds are man-made chemicals that are present in the environment at unnaturally high concentrations. The xenobiotic compounds are either not produced naturally, or are produced at much lower concentrations than man. Microorganism have the capability of degrading all naturally occurring compounds; this is known as the principle of microbial infallibility proposed by Alexander in 1965. Microorganisms are also able to degrade many of the xenobiotic compounds, but they are unable to degrade many others. The compounds that resist biodegradation and thereby persists in the environment are called recalcitrant The evolution of microbial catabolic enzymes cannot keep pace with the rapid introduction of novel compounds into the environment. These new synthetic compounds that are slowly biodegradable or non-biodegradable are known as recalcitrant compounds, and range from simple halogenated hydrocarbons to complex polym...

For biotoxification or Biodegradation of toxic substances Required a special enzyme which contain encoded gen on Plasmid Dr. Ananda Mohan Chakrabarty  and his co-workers are isolated a specific organism which is known as Pseudomonas putida in 1989.which can utilize some toxic chemical substances such as 3 chlorobenzene,ethylene etc. Pseudomonas putida  is a Gram-negative, rod-shaped, saprotrophic soil bacterium. V A variety of  P. putida , called multiplasmid hydrocarbon-degrading  Pseudomonas , is the first patented organism in the world. Because it is a living organism, the patent was disputed and brought before the United States Supreme Court in the historic court case  Diamond v. Chakrabarty , which the inventor, Ananda Mohan Chakrabarty, won . P. putida is a multiplasmid containing orgamism which contain more then one plasmid they introduce by genetic engineering different types of plasmid into a cell and forme...

Strains of the bacterium  Bacillus  thuringiensis  produce over 200 different Bt toxins, each harmful to different insects. Most notably, Bt toxins are insecticidal to the larvae of moths and butterflies, beetles, cotton bollworms and ghtu flies but are harmless to other forms of life. The gene coding for Bt toxin has been inserted into cotton as a transgene, causing it to produce this natural insecticide in its tissues. In many regions, the main pests in commercial cotton are lepidopteran larvae, which are killed by the Bt protein in the genetically modified cotton they eat. Bt cotton is ineffective against many cotton pests such as plant bugs, stink bugs, and aphids; depending on circumstances it may be desirable to use insecticides in prevention. Bt cotton was first approved for field trials in the United States in 1993, and first approved commercial use in the United States in 1995. In 2011, India grew the largest GM cotton crop at 10.6 million hectares. T...