Table 7-4.4.1 List of organisms degrading various petroleum hydrocarbons

Organism	Degrading Hydrocarbon(s)
Azoarcussp.strain EB1	Ethylbenzene
Azoarcussp.strain T	Toluene, m-Xylene
Azoarcustolulyticus	Toluene, m-Xylene
Pseudomonas sp.NAP3,EbN1,HdN1,M3,T3, ToN1 Vibrio sp. Strain NP4	Napthalene
ThaueraaromaticaK172,ThaueraaromaticaT1, GeobactergrbiciaeTACP5,Desulfobacterium cetonicum	Toluene
Desulfobacterium cetonicum strain AK-O1	C13-C18 alkanes
Desulfobacterium cetonicum strain NaphS2	Napthalene
Desulfobacterium cetonicum strain TD3	C6-C16 alkanes

Compiled from Bernard Ollivier, Mitchel Magot, Petroleum Microbiology, Amer Society for Microbiology, 2005
Approaches to GEM development for bioremediation application (Menn et al 2008)
1) Modification of enzyme specificity and affinity;
2) Pathway construction and regulation;
3) Bioprocess development, monitoring and control;
4) Bioaffinity/ bioreporter sensor applications for chemical sensing, toxicity reduction and end point analysis.
Genes responsible for degradation of environmental pollutants, for example, toluene, chlorobenzeneacids, xylene and other toxic wastes have been identified. Forevery compound, one separate plasmid is required. One single plasmid cannot able to degradeall the toxic compounds of different groups.

The plasmids are grouped into four categories:
1) OCT plasmid which degrades, octane, hexane and decane;
2) XYL plasmid which degradesxylene and toluenes,
3) CAM plasmid that decompose camphor and
4) NAH plasmid whichdegrades naphthalene (Ramos JL et al ).

The potential for creating microbial strains through genetic manipulation, which has ability to degrade avariety of hydrocarbons, has been demonstrated by Markandey DKet al. Theysuccessfully developed a multiplasmid-containing Pseudomonas strain capable of oxidizingaliphatic, aromatic, terpenic and polyaromatic hydrocarbons. GEM like Pseudomonas putida that contained the XYL and NAH plasmid as well as a hybrid plasmidderived by recombination of CAM and OCT developed by conjugation could degradecamphor, octane, salicylate, and naphthalene and could grow rapidly on crude oil because its capabilitiesof metabolizing hydrocarbons more efficiently than any other singleplasmid.