You all must be familiar with the word Superman– ‘An individual portrayed in movies having extraordinary abilities’. But have you heard of Superbugs? No… Don’t start guessing it yet. It has got nothing to do with a bug or an insect which can shoot lasers from its eyes or can do any of those superman stuffs, infact its not even a bug or an insect. Superbugs are the oil-eating bacteria, genetically engineered microorganisms used as a biological solution for treating oil spills. “Prof. Ananda Mohan Chakrabarty” is the Superbug Superhero who developed this genetically modified living organism. Oil spills in the oceans are among the most tedious jobs to be solved by humans and that too all by themselves. These superbugs, however proved to be a boon for the entire aquatic ecosystem as well as for the human society. In case of an accidental spill or leakage, the superbugs degrade most of the oil spills at a considerably faster pace.
What makes them super resilient?
The genetically engineered bacteria are known to degrade hydrocarbons. They possess the ability to degrade both, the unmanageable, as well as the highly toxic oil, all at once. This functional specificity is primarily due to the engineered plasmid of the oil-degrading bacteria. A plasmid is biologically defined as an extrachromosomal material of a bacteria besides nucleoid. Pseudomonas putida, for example, has a mixture of genes that can degrade two-thirds of the complex hydrocarbons. The desired piece of plasmids from potential bacteria having inherent oil degrading abilities are manipulated to obtain a recombinant form. Henceforth, this genetically engineered bacteria can now be used as a bio-remedial treatment for these pollutants.
Pseudomonas putida, a soil-dwelling bacterium, serves the chain of life by recycling nutrients. It secretes some enzymes that can break the dead and decaying organic matters into simpler substances such as Sugars and amino acids. It also produces a brownish pigment that turns yellow when dissolved in water and fluoresces a brilliant green colour when exposed to ultraviolet light.
Causes:
The oil spills are the consequences of the release of crude oil from tankers, drilling rigs and wells, leakage from loading ships. Natural as well as human activities have caused severe damages and around half of the oil spills are found to occur by these activities.
Oil spills are reported to heavily influence and harm the marine ecosystem by choking marine flora and fauna to death. The oil sticks to the fur of animals, birds or mammals, making it difficult for them to float in water and adjust their body temperature with the surrounding. Swallowing of these may even lead to their death due to its toxic effect. The excessive hydrocarbon components in these oils drastically changes the metabolism of the body.
Composition of Crude oil:
Petroleum oil is mainly composed of a complex mixture of hydrocarbons, and other organic compounds, including heavy metals- most notably organometallic constituents like Vanadium and Nickel. The crude oil is a natural, heterogeneous mixture of hydrocarbons with over 20,000 chemicals, consisting mainly of alkanes (that are highly branched and are of varying chain lengths), cycloalkanes, mono-aromatic and polycyclic aromatic hydrocarbons. Some compounds contain nitrogen, oxygen and sulfure and trace amount of phosphorous. The composition of the crude oil varies broadly in terms of physical and chemical properties, including solubility, thickness, capacity to absorb, as well as toxicity.
Bacteria utilize most of these hydrocarbons present in the marine environment as a carbon source primarily for their growth and reproduction. Crude oil consists significant amount of polycyclic aromatic hydrocarbons which are carcinogenic and also create neurological disturbances. It may accumulate in the biological food chains, thereby interfering with the normal process and creating intoxication problems for the most susceptible ones involved in the chain.
The quest to conquer oil spills:
Oil spills are the major cause of marine pollution. Finding a solution to this concern is as difficult as finding a needle in haystack. The occurrence of these spills, however can be avoided in order to prevent the associated consequences. The oil spills could be treated by physical, chemical and biological methods. The best possible ways are the most effective ones.
Physical solution
This method is comparatively easier than the other methods. It employs the burning of oil present on the surface thus evaporating it away from the ocean. The burning, however might also cause devastation to the marine flora and fauna present in the water. Also, this method of oil combustion from the surface of ocean further leads to air pollution.
GULF OF MEXICO- MAY 5: Gathered concentrated oil burns during a controlled oil fire May 5, 2010, in the Gulf of Mexico. The U.S. Coast Guard oversaw the oil burn after the sinking and subsequent massive oil leak because of the sinking of the Deepwater Horizon oil platform off the coast of Louisiana. (Photo by Justin E. Stumberg/U.S. Navy via Getty Images) 
PORT FOURCHON, LA – MAY 24: A BP cleanup crew shovels oil from a beach on May 24, 2010, at Port Fourchon, Louisiana. BP CEO Tony Hayward, who visited the beach, said that BP is doing everything possible to clean up the massive oil spill still gushing into the Gulf of Mexico. Officials now say, however, that it may be impossible to clean the hundreds of miles of coastal wetlands and islands affected. (Photo by John Moore/Getty Images)
Chemical Solution
In this method, the chemical encounter is achieved by either adsorption or by absorption process. This method includes the absorption of oil from the water. When oil spills in our house, we don’t wash it with water, instead we place a tissue paper or cotton cloth on it to absorb it first; then clean it with soap or detergent. Similarly, natural solvents such as corn cobs, cotton, milkweed, wood, rice straw, etc. are used in this type of solution. The sorbents could be in powder form which is commercially available as a mixture of hygroscopic magnesium carbonate with palmitic acid.
Also, the oil dispersants (such as Dispone 36 S, COREXIT 9527 etc.) play an important role in breaking the oil globules into smaller droplets thus preventing cytotoxicity problems. On the shoreline, sea birds’ eggs are vulnerable to oil, which alone creates embryo toxicity. Some dispersants aren’t used due to their toxicity interfering with the respiration of bivalves and clams. As a result, this method effectively cleans upto 80% of surface oil.
Biological Solution
To overcome the former problems of physical and chemical methods and to prevent their negative impacts, biological solution can be used well off. The species belonging to genera Alcanivorax, Pseudomonas, Acinetobacter etc. metabolise oil as the sole source of carbon. They do so by the process of “bioremediation”. The use of these microorganisms for the removal of pollutants can be thus employed owing to their diverse metabolic pathways.
Bioremediation
Bioremediation is an economical and commercial technique for cleaning and restoring the sites with no harmful side effects. It thus completely solves the concern of air pollution and water pollution. Microorganisms, especially bacteria and fungi are the major decomposers and recycling agents in the environment. They can transform the complex aliphatic or aromatic or polycyclic hydrocarbons and use them as an energy source.
Sometimes the already present oil-degrading bacteria in the marine biome are incapable of bioremediation. Hence, to achieve sufficient bioremediation, the known oil-eating bacteria are added externally at the oil spill sites. This process is known as Bioaugmentation.
The environmental factors affecting the biological processing:
The major steps include oxidation, evaporation, sedimentation, emulsion and dispersion. These steps are primarily affected by environmental factors such as light, atmosphere, carbon dioxide, etc. The volatile components evaporate readily, thus helping the microorganisms to degrade more efficiently. The action of microorganisms is oxygen-dependent, which means they utilize the carbon source in the presence of oxygen. Therefore, most of them are aerobic in nature. The first enzyme made in the process is Oxygenase- an enzyme that helps in oxidizing a substance by transferring oxygen. Therefore, oxygen depletion can limit the efficiency of bioremediation.
Every organism has its capacity to sustain and resist. Superbugs are super-resistant, but eco-friendly microorganisms modified for human welfare.
The superbug superhero:
In 1971, Prof. Ananda Mohan Chakraborty, a distinguished Indian-born American microbiologist and scientist was recognised for the development of a genetically engineered Pseudomonas. “An oil-eating bacteria” also known as “Superbug”. He transferred the genes required for the degradation of oil using a plasmid vector and as a result, produced a genetically stable species of bacteria, now known as Pseudomonas putida. Prof. Chakrabarty used four strains of Pseudomonas and then fused all four strain’s plasmids to create a superbug. These four strains independently degrade the chemical compound octane, camphor, xylene, and naphthalene. Chakraborty called it a “multi-plasmid hydrocarbon-degrading Pseudomonas” which is capable of digesting nearly all types of hydrocarbon found in typical oil spills at a faster pace than previously known existing strains of oil-eating microbes.
The genetically modified bacteria are also capable of tolerating high salinity, extreme temperature, adapting to the sudden fluctuations in the surroundings. They can withstand the highly toxic chemicals present in the spills.
It took 9 years to patent the genetically modified ‘live organism’. His appeal was denied by the court because the organism was living and naturally occurring. But, he proved that the bacterium is genetically modified. This is why Prof. Chakrabarty is also known as the “Father of Patent Microbiology”.
Conclusion:
These genetically engineered microorganisms are efficient enough to remove majority of the oil spills. However, the modified genes do consume time and are costly as well. The need of proper maintenance, labour or manpower are also proposed as a major concern when using these. However, despite numerous problems, they are worth it.
For example, consider oil spills at a site where no human can reach such as polar regions, deep wells, glaciers etc. In such cases the presence of microorganisms simplifies the task. The glaciers, if left untreated, will melt when there is a temperature rise, which will direct its water into rivers. This polluted water will further be consumed by animals and humans and thus pose serious health problems to all.