The pharmaceutical industry is responsible for the environmental pollution imposed by drugs, heavy metals, and surfactants. In-situ remediation of pharma pollutants with the cell-based system has some limitations like sensing of contaminants, efficacy, cost, concentration of pollutants, toxicity level, etc. Synthetic biology is important for gene mining, enzymes discovery, and biodegradation pathway of pollutants. The chapter is based on the synthetic systems for remediation of the pharma pollutants.
TopIntroduction
Pharmaceutical wastes are one of the emerging pollutants to the ecosystem. Reports are available on their presence in water bodies, soil and WWTPs affecting the human and other life forms (Khetan and Collins, 2007; Kosjek and Krbavcic, 2005). Sources of pharmaceutical wastes are manufacturing industries, health care units, residential wastewater etc. (Gadepalli et al., 2014). Pharmaceutical wastes involve dyes (azo, triphenylmethane dyes, xanthine dyes, and quinoline dyes), surfactants (sodium dodecyl sulphate (SDS) and cetrimonium salt (ATAC-C16)), antimicrobial compounds, synthetic musk’s, hormones, preservatives, heavy metals (copper, cadmium, lead, nickel, chromium and zinc) (Chaturvedi et al., 2021; Chimezie et al., 2011; Gicevic et al., 2019). Azo dyes used in pharma industries are E133 Brilliant Blue, E102 Tartrazine, Ponceau 4R (Cochineal Red A), E110 Sunset Yellow FCF, Azorubine (Carmoisine), Amaranth, and E129 Allura Red, contains benzene rings which makes them harmful (Gicevic et al., 2019; Pawar and Kumar, 2002). Persistence of drugs in water is due to their high-water solubility, non-detectable effective concentration, and bioaccumulation. In waste water treatment plants, attention was given on the removal of physical objects and chemical residues. But with the recent research, concept of genomic surveillance of waste water treatment plants is emerging as a part of epidemiology. Brief outline of genomic surveillance of WWTP is given in Fig. 1. Genomic surveillance is important to find the chances of infection through antigens or mobile genetic elements as well as development of antimicrobial resistance in nosocomial pathogens (Rodriguez et al., 2021). During covid 19 pandemic situation, genomic surveillance was done via next generation sequencing to find out the antigenic variation in virus as well as effect of vaccine against this viral pathogen to control morbidity and mortality rates (Robishaw et al., 2021).
Pharma wastes removal from the waste water treatment plant has been carried out with the help of physico-chemical or biological methods. Biological methods are less costly and eco- friendly as compared to physico-chemical methods. In biological methods, aerobic and anaerobic microorganisms are used in free or immobilized form.
Bioremediation is the method which depends on the natural biological activity for the reduction in the toxicity of harmful compounds (Vidali, 2001). Biological contribution for the remediation of toxicants is one of the extensively studied research topic due to the changes in the microbial behavior or alteration of the microbial community in presence of toxicant (Iwamoto and Nasu, 2001). With the progressive developments in the field of molecular biology, researchers are trying to explore the activity of culturable as well as unculturable bacteria. To find out the microbial load in the contaminated area, advanced molecular microbiological methods are required to optimize and validate the process of bioremediation (Iwamoto and Nasu, 2001). For the effective bioremediation process, some factors like viability of microorganisms, optimal concentration of pollutant, environmental conditions like pH, temperature, gases etc. are important. To circumvent the issues related with the environmental performance of bacteria, synthetic systems can be the promising technology.
Figure 1. Genomic surveillance of waste water treatment plant