The Bacteroidetes Aequorivita sp. and Kaistella jeonii Produce Promiscuous Esterases With PET-Hydrolyzing Activity

• DOI: 10.3389/fmicb.2021.803896
• Publication Date: 2022-01-05T08:17:46Z
• Authors: Hongli Zhang; Pablo Perez-Garcia; Robert F. Dierkes; Violetta Applegate; Julia Schumacher; Cynthia Maria Chi...; Stefanie Sternagel; Lena Preuss; Sebastian Weigert; Christel Schmeisser; Dominik Danso; Juergen Pleiss; Alexandre Almeida; Birte Höcker; Steven J. Hallam; Ruth A. Schmitz; Sander H. J. Smits; Jennifer Chow; Wolfgang R. Streit
• Keywords: info:eu-repo/classification/ddc/570; metagenomics; 570; PETase; Bacteroidetes; PET degradation; metagenomic screening; 540; Microbiology; polyethylene terephthalate (PET); QR1-502

Certain members of the Actinobacteria and Proteobacteria are known to degrade polyethylene terephthalate (PET). Here, we describe first functional PET-active enzymes from Bacteroidetes phylum. Using a PETase-specific Hidden-Markov-Model- (HMM-) based search algorithm, identified several PETase candidates Flavobacteriaceae Porphyromonadaceae. Among them, two promiscuous cold-active esterases derived Aequorivita sp. (PET27) Kaistella jeonii (PET30) showed depolymerizing activity on polycaprolactone (PCL), amorphous PET foil polyester polyurethane Impranil® DLN. PET27 is 37.8 kDa enzyme that released an average 174.4 nmol terephthalic acid (TPA) after 120 h at 30°C 7 mg platelet in 200 μl reaction volume, 38-times more than PET30 (37.4 kDa) under same conditions. The crystal structure without its C-terminal Por-domain (PET30ΔPorC) was solved 2.1 Å displays high structural similarity IsPETase. shows Phe-Met-Tyr substrate binding motif, which seems be unique feature, as IsPETase, LCC PET2 all contain Tyr-Met-Trp residues, while possesses Phe-Met-Trp motif identical Cut190. Microscopic analyses K. cells indeed able bind colonize surfaces few days incubation. Homologs were detected metagenomes, predominantly aquatic habitats, encompassing wide range different global climate zones suggesting hitherto unknown influence this bacterial phylum man-made polymer degradation.