Table 3.

Strategies commonly used for microbial degradation of plastic.

Strategy	Approach	Components	Constitution	Mode of Action	References
I	Prebiotic	Prooxidant	Salt of iron, manganese, cobalt, titanium	Accelerate oxidation of polymer	[161-163]
		Biosurfactants	Starch, cellulose, Glycoproteins, lipopeptides, and other polymeric biosurfactants, bacterial exopolysaccharide	Reduce surface tension of plastic substances and helps in the adhesion of microorganisms	[89, 164]
		Stimulants	Organic compounds e.g. amino acids, cofactors, Citrate, succinate, etc.	Stimulate the growth of anaerobic and methanogenic bacteria	[146, 165]
		Nutrients	Nitrogen, Potasium, Phosphorus, Sulphur	To avoid deficiency of certain essential elements, also acts as the biostimulent	[7, 166]
		Protectants	KMnO4	Reduces the toxicity of triclosan, leachates from degraded plastics on diatoms and other microbes	[91]
	Probiotic	Bioauguments of microbial consortia	Actinobacteria, Bacteroidetes, Proteobacteria, Ascomycetous fungi	Helps in the colonization and complex polymer degradation	[167]
		Microbiota transplantation	Core and specific microbial population	Replacement of indigenous population, and establishment of new population	[168, 169]
II	Ex situ microbial genome engineering	Gene insertion	PETase	To genetically engineer microbes for complex polymer degradation	[101]
		Gene/Protein engineering	PETase	To increase the bioefficacy and thermal stability	[103]
	In situ metagenome engineering	Horizontal gene transfer	Plasmid, transposable element	To disseminate the genes (enzymes) among indigenous microbial population	[170]