Dataset Information

Environmental Consortium Containing Pseudomonas and Bacillus Species Synergistically Degrades Polyethylene Terephthalate Plastic.

ABSTRACT: Plastics, such as polyethylene terephthalate (PET) from water bottles, are polluting our oceans, cities, and soils. While a number of Pseudomonas species have been described that degrade aliphatic polyesters, such as polyethylene (PE) and polyurethane (PUR), few from this genus that degrade the semiaromatic polymer PET have been reported. In this study, plastic-degrading bacteria were isolated from petroleum-polluted soils and screened for lipase activity that has been associated with PET degradation. Strains and consortia of bacteria were grown in a liquid carbon-free basal medium (LCFBM) with PET as the sole carbon source. We monitored several key physical and chemical properties, including bacterial growth and modification of the plastic surface, using scanning electron microscopy (SEM) and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) spectroscopy. We detected by-products of hydrolysis of PET using ¹H-nuclear magnetic resonance (¹H NMR) analysis, consistent with the ATR-FTIR data. The full consortium of five strains containing Pseudomonas and Bacillus species grew synergistically in the presence of PET and the cleavage product bis(2-hydroxyethyl) terephthalic acid (BHET) as sole sources of carbon. Secreted enzymes extracted from the full consortium were capable of fully converting BHET to the metabolically usable monomers terephthalic acid (TPA) and ethylene glycol. Draft genomes provided evidence for mixed enzymatic capabilities between the strains for metabolic degradation of TPA and ethylene glycol, the building blocks of PET polymers, indicating cooperation and ability to cross-feed in a limited nutrient environment with PET as the sole carbon source. The use of bacterial consortia for the biodegradation of PET may provide a partial solution to widespread planetary plastic accumulation.IMPORTANCE While several research groups are utilizing purified enzymes to break down postconsumer PET to the monomers TPA and ethylene glycol to produce new PET products, here, we present a group of five soil bacteria in culture that are able to partially degrade this polymer. To date, mixed Pseudomonas spp. and Bacillus spp. biodegradation of PET has not been described, and this work highlights the possibility of using bacterial consortia to biodegrade or potentially to biorecycle PET plastic waste.

SUBMITTER: Roberts C

PROVIDER: S-EPMC7763552 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Environmental Consortium Containing Pseudomonas and Bacillus Species Synergistically Degrades Polyethylene Terephthalate Plastic.

Roberts Cameron C Edwards Sabrina S Vague Morgan M León-Zayas Rosa R Scheffer Henry H Chan Gayle G Swartz Natasja A NA Mellies Jay L JL

mSphere 20201223 6

Plastics, such as polyethylene terephthalate (PET) from water bottles, are polluting our oceans, cities, and soils. While a number of Pseudomonas species have been described that degrade aliphatic polyesters, such as polyethylene (PE) and polyurethane (PUR), few from this genus that degrade the semiaromatic polymer PET have been reported. In this study, plastic-degrading bacteria were isolated from petroleum-polluted soils and screened for lipase activity that has been associated with PET ...[more]

PMID: 33361127

Similar Datasets

Project description:Biodegradation of terephthalate (TPA) is a highly desired catabolic process for the bacterial utilization of this polyethylene terephthalate (PET) depolymerization product, but to date, the structure of terephthalate dioxygenase (TPDO), a Rieske oxygenase (RO) that catalyzes the dihydroxylation of TPA to a cis-diol, is unavailable. In this study, we characterized the steady-state kinetics and first crystal structure of TPDO from Comamonas testosteroni KF1 (TPDOKF1). TPDOKF1 exhibited substrate specificity for TPA (kcat/Km = 57 ± 9 mM-1 s-1). The TPDOKF1 structure harbors characteristic RO features as well as a unique catalytic domain that rationalizes the enzyme's function. The docking and mutagenesis studies reveal that its substrate specificity for TPA is mediated by the Arg309 and Arg390 residues, positioned on opposite faces of the active site. Additionally, residue Gln300 is also proven to be crucial for the activity, as its mutation to alanine decreases the activity (kcat) by 80%. This study delineates the structural features that dictate the substrate recognition and specificity of TPDO. IMPORTANCE Global plastic pollution has become the most pressing environmental issue. Recent studies on enzymes depolymerizing polyethylene terephthalate plastic into terephthalate (TPA) show some potential for tackling this. Microbial utilization of this released product, TPA, is an emerging and promising strategy for waste-to-value creation. Research in the last decade has identified terephthalate dioxygenase (TPDO) as being responsible for initiating the enzymatic degradation of TPA in a few Gram-negative and Gram-positive bacteria. Here, we determined the crystal structure of TPDO from Comamonas testosteroni KF1 and revealed that it possesses a unique catalytic domain featuring two basic residues in the active site to recognize TPA. Biochemical and mutagenesis studies demonstrated the crucial residues responsible for the substrate specificity of this enzyme.

Dataset Information

Environmental Consortium Containing Pseudomonas and Bacillus Species Synergistically Degrades Polyethylene Terephthalate Plastic.

Publications

Environmental Consortium Containing <i>Pseudomonas</i> and <i>Bacillus</i> Species Synergistically Degrades Polyethylene Terephthalate Plastic.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets