Companies like BioTechnica are working on treating polluted sites in situ. In this connection, it is interesting to note that the first patent ever awarded was given to Dr. Ananda Chakrabarty of General Electric (USA) for developing a microbe designed to biodegrade spilled oil (see later in this chapter for details).

There has been a debate on whether or not to release genetically engineered microbes for treatment of toxic sites. It is argued that biotechnology products parallel toxic chemicals in many respects and unlike chemicals, released engineered organisms have the capacity to reproduce and spread beyond the initial release sites and may even transfer novel genes into other naturally occurring organisms, thus causing the risk of developing what are described superbugs.

In view of the above, 'Occidental Chemical Corporation' company of USA is conducting their work, on effluents from toxic waste sites (Love Canal and other polluted sites in USA), in closed reactors. One such experiment was conducted at Hyde Park landfill site at the northwest corner of Niagara, New York.

Therefore, the Hyde Park wastewater was subjected to biotreatment in sequencing batch reactors (SBRs), where biodegradation rate of some more persistent chemicals was accelerated by adding bacterial strains isolated from the landfill site.

Further genetic manipulation of these organisms produced more than 100 recombinant bacteria, which have been tested for their usefulness in reactors. It was demonstrated that significant cost savings will be possible, if SBR treatment is used before the carbon absorption stage.

Several other companies that are reported to be active in toxic site clean up in USA include the following: Detox Industries, Kerr-McGee, Polybac and Sybron Chemical. The developments in this field have regularly been highlighted in several international symposia held during the last decade.