Introduction

The different industrial processes that came due to civilisation resulted in the production of waste that is toxic to the environment and poses a threat to health of humans and other organisms, thus hazardous. These wastes can either be organic or inorganic. Hazardous waste can be placed into four groups and these are flammable waste, toxic waste, highly reactive waste and corrosive waste. Waste can be detrimental to human health either by coming into contact with it, breathing it in or by ingestion. Most of industrially produced waste is not readily or successfully degraded mechanically using chemicals or by burning, for instance. Therefore alternative waste management tools have to be used.

Bioremediation

Microorganisms are organisms that are not visualised by the naked eye. These organisms include bacteria, fungi and protists. Most of these organisms are saprophytes, feeding by degrading organic material in the environment. This can thus serve as a way of managing waste and waste that can be degraded by these organisms is regarded as being biodegradable. The removal of waste material from the environment by microorganisms is referred to as Bioremediation. Bioremediation is not a new concept but now with advances in science, it has been taken to new levels.

Bringing in Biotechnology

Metabolomics, where the genome of organism from environmental samples is studied, have provided a tool that can be used to identify genes that are expressed in environments that have accumulated waste materials. This is because by taking samples from environments to which waste have been dumped, and studying life that can tolerate these waste materials, then geneticists can identify the proteins that allows the organisms to survive under such environments. These microorganisms can then be used directly to treat the environment more so if they break down the waste material into safe molecules such as water and carbon dioxide. Identified genes can also be over-expressed in the same organisms or different ones in order to make them more efficient at remedying the environment. Different microorganisms are active in breaking down different waste materials in the environment. Thus if the waste is comprised of different compounds e.g. nitrogen, phosphorous etc, and then organisms that can degrade these different compounds can be identified and used to remedy the environment. Ideally, the different genes from different organisms might be cloned into one so that it can degrade more than one, though this still remains quite a challenge in genetic engineering, to genetically modify organisms with multiple genes.

Some microorganisms do not break down waste but rather accumulates it at very high levels without dying. The genes responsible for the organisms to accumulate and tolerate these toxic levels of waste can be identified in environmental samples. These genes can then be genetically engineered into maybe bigger organisms that have a higher carrying capacity, like plants, thus using the plants which will now be able to remove hazardous material from the environment, and surviving those toxic levels. A typical example of an organism that was bioengineered for bioremediation is where Pseudomonas fluorescence that was growing in a gas plant facility contaminated with polyaromatic hydrocarbons was bioengineered with a naphthalene catabolic plasmid. This made the bioengineered strain to respond to naphthalene presence by increasing levels of its catabolic gene expression which result in an increased degradation of naphthalene. This bioengineered strain of P. fluorescence was named HK44.

Conclusion

Genetically modifying organisms to improve bioremediation is still a challenge as this organisms might be fragile in the field and thus before they can be release into the environment, they have to be extensively studied in a research field. Also the organisms are bioengineered to be a lot "hungrier" for carbon, relatively speaking. Thus when the carbon supply goes down, as in when waste gets degraded; the organisms demand for carbon might not be satisfied. Thus ways of counteracting these problems have to be investigated and researchers from different fields of biology including biotechnology, are working together to come up with a strategy that can be adopted and will work more efficiently to tackle the ever increasing waste in the environment.

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