The present invention describes a process of manufacturing biodegradable PET chips, comprising the steps of providing a purified terephthalic acid (PTA) in a predetermined quantity in a slurry tank; providing virgin monoethylene glycol (MEG) in a predetermined quantity in the slurry tank; transferring the combination of the slurry tank to an esterification reactor for esterification of the combination in the reactor at above 250° C. temperature which releases monomers; transferring the monomers from the esterification reactor to a polymerisation reactor; providing poly-catalysts such as, but not limited, to Ti-based catalyst, sb2O3 or any other suitable catalysts or combination thereof into the polymerisation reactor; and polymerization of the monomers in the polymerisation reactor at above 280° C. temperature, wherein an enzyme based composition is provided either at PTA/MEG stage or poly-catalyst stage or at other stages or combination thereof.