A revolution in waste management
Using the power of SynBio and recombinant bacteria for developing better waste management solutions.
Today, we have rapidly progressed in the field of Synthetic biology. In modern times, its applications extend to agriculture, health, food processing, bioenergy and various industrial products. Slowly, we have also progressed to use synthetic biology in the field of environmental conservation too.
Industrial production has sky-rocketed in modern times to fulfil the needs of an increasing population which has also led to the release of toxic substances and waste products into the environment. Likewise, urban sewage, household waste, medical waste from hospitals, increasing vehicles on roads, extreme use of chemicals in farming, remains of dairy farms, harmful by-products from refineries, increasing use of plastic are contributing to manifold increase in pollution levels. Various countries from across the world have initiated treatment of these pollutants with the help of SynBio.
Once the sewage is passed through primary treatments wherein sludge and other oils & grease are removed from it, the application of SynBio is seen at the secondary stages. To digest the carbonic substances pseudomonas, micrococcus, nitrosomonas sardinia, staphylococcus and achromobacter are used. In the airlift bio-reactors, zoogloea ramigera is used for the production of bio-films and energy. Nitrosomonas and nitrobacter are used for digestion of ammonia, which converts them into nitrate. Then achromobacter (alcaligenes) and pseudomonas is used to convert these nitrates into nitrogen. Similarly, many protozoa, fungi and algae are placed on the periphery of these bio-films in bioreactors which digests phosphorus, nitrogen and other nutrients. Anaerobic bio-reactors in a similar fashion uses anaerobic bacteria viz. denitrificans, desulfovibrio, methanopterin, etc. which are used to digest fats, carbohydrates and proteins to produce methane and carbon dioxide.
Biofilm system could be a well-developed technology within which solid media are applied to suspended growth reactors to supply attachment surfaces for biofilms, thus on increase the microorganism concentration further as rates of contaminant degradation biofilms to require advantage of a variety of removal mechanisms, together with biodegradation, bioaccumulation, biosorption and biomineralization. The microorganism communities within the biofilm break down completely different nutrients, like chemical element and nitrogen-containing compounds, phosphorous materials further as treed pathogens from the effluent. Once pollutants are removed, treated water of a biofilter is either discharged to the atmosphere or used for agriculture and different recreational functions. Removal of the pollutants from effluent by biofilm on the filter media is schematically portrayed in Figure.
Wastewater treatment with biofilm systems has many benefits, together with operational flexibility, low area necessities, reduced hydraulic retention time, resilience to changes within the atmosphere, increased biomass continuance, high active biomass concentration, increased ability to degrade recalcitrant compounds as well as a slower microorganism rate of growth, leading to lower sludge production.
Homologous DNA recombination technique has led to the development of such bacteria which can digest inorganic compounds too. This, in turn, has allowed us to remove the large quantities of pesticides which contain inorganic chemicals from the human body. Also, sea algae have been engineered such to absorb D.D.T. and other harmful chemicals from the water. Recently, scientists were also able to develop a ‘super enzyme’ which degrades plastic six times faster than the earlier developed ones.
The super-enzyme was created by mixing two separate enzymes, which were found in a plastic-eating bug discovered at a Japanese waste site in 2016. Two years after the initial discovery, researchers revealed an engineered version of the first enzyme that was able to break down plastic in a few days. They determined that the structure of the enzyme, called PETase, can attack the hard, crystalline surface of plastic bottles and that one mutant version of it worked 20% faster. The latest study, published in Proceedings of the National Academy of Sciences, analyzed the second enzyme, which doubles the speed of the breakdown of the chemical groups liberated by the first enzyme. Now they took this already existing enzyme called PETase within Ideonella sakaiensis bacteria and combined it with a second enzyme, MHETase. The specific bacteria are already known to feed off the plastic, so it turns out to be a genius idea to back its enzyme up with the second enzyme and increase the speed of activity by further three times, hence leading to the total six-time increase in plastic degradation.
Biotechnology is contributing immensely to the field of waste management and there is a hope that these steps would prove to be prominent for environment conservation soon.
