THE CARMEL BEAT
Biotechnology For Pollution Control
Akanksha C A & Rupashri Balaraman, Biogeneiac Association
Introduction
In the last few decades, our knowledge of biotechnology and its practical applications has tremendously increased with the expanding research that is being done globally. One of the important fields in biotechnology that is being explored more especially at a time like now is environmental biotechnology.
Environmental biotechnology addresses many of the current threats to our environment caused by man-made activities, by wielding biotechnological discoveries. These discoveries include genetically engineering bacteria and other multicellular organisms, or cells in the lab to make them help clean up our environment and give us sustainable alternatives to the toxic everyday materials in current use. Living organisms and biological processes can be exploited to help us remove pollutants and toxic substances, generate renewable energy, and in the advancement of sustainable processes in manufacturing.
As we are well aware, pollution and its destructive effects on the environment is becoming increasingly worrying with every passing day, leaving mass effects on the planet. Scientists and researchers are vigilant in discovering novel alternatives that are environment-friendly, that can reverse and remedy the detrimental effects of pollution.
Here, we will briefly go over some eco-biotechnological discoveries that are promising in the cleanup of the environment from damage caused by different types of pollution.
Microbial Technology
Industries and vehicles are the major contributing units of society towards polluting the air. These units release carbon dioxide, sulphur dioxide, sulphides and nitrates into the environment which combine with many other pollutants in the environment and result in irreversible consequences both on health and environment.
There are multiple processes to reduce the amount of polluting gases from being released into the environment. But an alternate way to reduce the escape of these gases is eliminating the source of sulphur in the fuel before it can even be utilized and released as gas.
Sulphur in coal used for fuel can be reduced by special organisms that can leach out sulphur from it. The thiobacillus species are particularly able to oxidise sulphur into its non-reactive low-grade oxides and hence, stop it from entering the air and contributing to pollution in the form of sulphur dioxide, a prominent greenhouse gas. However, this process, although it sounds easy, is difficult to conduct since the microbial species needs to have a constant temperature at which it can function effectively, and maintaining these optimum conditions is tiresome and also five times more expensive than using normal bioscrubbers.
Bioremediation:
Many industrial and commercial processes release a lot of contaminated wastewater with many toxic substances and pathogenic microbes. Several stages of wastewater treatment remove all these contaminants and organic matter. One of the steps involves biodegradation by means of harnessing microorganisms present in the activated sludge (which is wastewater with a high concentration of microorganisms). Our wastewater treatment plants currently are expensive and tedious to build and maintain, and moreover, all the contaminants are not cleared. A few new strategies are being developed to this end, such as bioremediation.
Here, we add specific, efficient pollutant-degrading microbes to enhance the ability of the microbial population already present in the sludge. Bioremediation involves adding tailored microbes specific to pollutant compounds that are complex and resistant to biodegradation.
For instance, quinoline is a recalcitrant pollutant found in wastewater generated by petroleum plants. A novel strain isolated from the Bacillus species of bacteria, called the Q2 strain was bioaugmented to utilise quinoline as its sole source of energy, and thus degrades quinoline in wastewater efficiently.
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This is just one of the several pollutant compounds in wastewater such as nicotine from tobacco industry, cyanide from coke plants, pyridine from pharmaceutical industries and many more that can be degraded by bioremediation strategies Another significant example is using genetically modified bacteria of the Pseudomonas species, which can degrade petroleum and oil. In accidents such as oil spills and leakages from oil pipelines and oil storage tanks, these petroleum-degrading bacteria can be used to treat pollution. Pseudomonas strains of bacteria were genetically engineered with plasmids containing genes that coded for catabolic enzymes that could biodegrade petroleum compounds
(Credit: www.thedirtdoctors.com/poplar-trees
(Credit: www.yourgenome.org )
Phytotechnology:
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It entails using plants to degrade or extract pollutants to remedy the environment, by suitably modifying or augmenting the plant DNA in the lab, now called transgenic plants.
We are all aware of gases released by vehicles and factories that cause air pollution, but a few particular species of economically important trees, like poplars, produce an organic compound called isoprene in response to environmental stressors like climate change and temperature change, which can be harmful to living organisms when they react with other atmospheric pollutants. Poplars are extremely important trees used in plantation agroforestry, they provide us with paper, biofuel, plywood, and furniture frames so cutting down these trees to stop this compound from being released is not a likely proposition. Researchers have worked on altering the plant’s genes using a biotechnological process called “RNA interference”, where small pieces of RNA bind to the region coding for proteins responsible for a particular process, and inhibit the production of said proteins. Therefore, the production of isoprene is suppressed and other alternate processes are activated which function in the same way without affecting the plant or the environment.
Credit: www.sciencephoto.com )
Trinitrotoluene (TNT) is a well known, persistent and dangerous explosive. The use and disposal of TNT has resulted in the contamination of many sites, and it is very difficult in expense and time to clean up. A bacterial gene encoding an enzyme that could degrade TNT was taken and transferred into tobacco plants by gene transfer. These transgenic tobacco plants can now express the gene and degrade TNT in the soil when planted.
References/Sources of Information:
[1] Genetically modifying trees to prevent air pollution
[3] Bioaugmentation: An Emerging Strategy of Industrial Wastewater Treatment for Reuse and Discharge
[4] Phytotechnology – A Green Key To Fighting Soil Pollution
[5] Gareth M. Evans, Judith C. Furlong. Environmental Biotechnology - Theory and Application. (John Wiley & Sons Ltd. 2003.)