Evidence　for　microbial　biodegradation　of　polyethylene　terephthalate　(PET)　has　been　reported,　but　little　is　known　about　the　PET　biodegradation　process　and　molecular　mechanism　by　marine　microorganisms.　Here,　we　show　the　biodegradation　of　PET　by　the　membrane-anchored　PET　esterase　from　the　marine　bacterium　Rhodococcus　pyridinivorans　P23,　elucidate　the　properties　of　this　enzyme,　and　propose　the　PET　biodegradation　by　this　strain　in　biofilm.　We　identify　the　PET-degrading　enzyme　dubbed　PET　esterase　through　activity　tracking.　In　addition　to　depolymerizing　PET,　it　hydrolyzes　MHET　into　TPA　under　acid　conditions.　We　prove　that　it　is　a　low　and　constitutively　transcribed,　membrane-anchored　protein　displayed　on　the　cell　surface.　Furthermore,　we　also　investigate　the　microbial　groups　possessing　PET　esterase　coupled　with　the　TPA　degradation　pathway,　mainly　in　the　phyla　Proteobacteria　and　Actinobacteriota.　Clarification　of　the　microbial　PET　biodegradation　in　the　marine　environment　will　contribute　to　the　understanding　of　bioremediation　of　marine　PET　pollution.