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Publication Abstract from PubMed

Certain members of the Actinobacteria and Proteobacteria are known to degrade polyethylene terephthalate (PET). Here, we describe the first functional PET-active enzymes from the Bacteroidetes phylum. Using a PETase-specific Hidden-Markov-Model- (HMM-) based search algorithm, we identified several PETase candidates from Flavobacteriaceae and Porphyromonadaceae. Among them, two promiscuous and cold-active esterases derived from Aequorivita sp. (PET27) and Kaistella jeonii (PET30) showed depolymerizing activity on polycaprolactone (PCL), amorphous PET foil and on the polyester polyurethane Impranil((R)) DLN. PET27 is a 37.8 kDa enzyme that released an average of 174.4 nmol terephthalic acid (TPA) after 120 h at 30 degrees C from a 7 mg PET foil platelet in a 200 mul reaction volume, 38-times more than PET30 (37.4 kDa) released under the same conditions. The crystal structure of PET30 without its C-terminal Por-domain (PET30DeltaPorC) was solved at 2.1 A and displays high structural similarity to the IsPETase. PET30 shows a Phe-Met-Tyr substrate binding motif, which seems to be a unique feature, as IsPETase, LCC and PET2 all contain Tyr-Met-Trp binding residues, while PET27 possesses a Phe-Met-Trp motif that is identical to Cut190. Microscopic analyses showed that K. jeonii cells are indeed able to bind on and colonize PET surfaces after a few days of incubation. Homologs of PET27 and PET30 were detected in metagenomes, predominantly aquatic habitats, encompassing a wide range of different global climate zones and suggesting a hitherto unknown influence of this bacterial phylum on man-made polymer degradation.

The Bacteroidetes Aequorivita sp. and Kaistella jeonii Produce Promiscuous Esterases With PET-Hydrolyzing Activity.,Zhang H, Perez-Garcia P, Dierkes RF, Applegate V, Schumacher J, Chibani CM, Sternagel S, Preuss L, Weigert S, Schmeisser C, Danso D, Pleiss J, Almeida A, Hocker B, Hallam SJ, Schmitz RA, Smits SHJ, Chow J, Streit WR Front Microbiol. 2022 Jan 5;12:803896. doi: 10.3389/fmicb.2021.803896., eCollection 2021. PMID:35069509^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.