LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA MELGTLEGSEFAGGGGDGGDGGCTSDCGFQRGPDPTVSFLEASSGPYSVR TDNVSSLVGGFGGGTVHYPTGTTGTMAAVVVIPGFVSAESSIEWWGPKLA SYGFVVMTIDTNSGFDQPPSRATQINNALDYLLEENDSSSSPYSGMIDPN RLGVIGWSMGGGGTLRVAAEGRIQAAIPLAPWDTSSLRFRNIETPTLIFA CESDVIAPVGSHADPFYEAIPDSTDKAFFELNNGSHYCGNGGNSYNNELG RLGVSWMKLHLDQDQRYNQFLCGPDHEDEYRISEYRGTCPYLE
Polybutylene adipate terephthalate (PBAT) is a biodegradable alternative to polyethylene and can be broadly used in various applications. These polymers can be degraded by hydrolases of terrestrial and aquatic origin. In a previous study, we identified tandem PETase-like hydrolases (Ples) from the marine microbial consortium I1 that were highly expressed when a PBAT blend was supplied as the only carbon source. In this study, the tandem Ples, Ple628 and Ple629, were recombinantly expressed and characterized. Both enzymes are mesophilic and active on a wide range of oligomers. The activities of the Ples differed greatly when model substrates, PBAT-modified polymers or PET nanoparticles were supplied. Ple629 was always more active than Ple628. Crystal structures of Ple628 and Ple629 revealed a structural similarity to other PETases and can be classified as member of the PETases IIa subclass, alpha/beta hydrolase superfamily. Our results show that the predicted functions of Ple628 and Ple629 agree with the bioinformatic predictions, and these enzymes play a significant role in the plastic degradation by the consortium.
The degradation of synthetic polymers by marine microorganisms is not as well understood as the degradation of plastics in soil and compost. Here, we use metagenomics, metatranscriptomics and metaproteomics to study the biodegradation of an aromatic-aliphatic copolyester blend by a marine microbial enrichment culture. The culture can use the plastic film as the sole carbon source, reaching maximum conversion to CO(2) and biomass in around 15 days. The consortium degrades the polymer synergistically, with different degradation steps being performed by different community members. We identify six putative PETase-like enzymes and four putative MHETase-like enzymes, with the potential to degrade aliphatic-aromatic polymers and their degradation products, respectively. Our results show that, although there are multiple genes and organisms with the potential to perform each degradation step, only a few are active during biodegradation.
Marinobacter Hydrolase (PETase-like) Cold-Adapted PET Hydrolase Ple628
