Metagenomic Sequencing of Two Cultures Grown on Chemically Deconstructed Plastic Products

ABSTRACT We report the metagenome sequences of two microbial cultures that were grown with chemically deconstructed plastic products as their sole carbon source. These metagenomes will provide insights into the metabolic capabilities of cultures grown on deconstructed plastics and can serve as a starting point for the identification of novel plastic degradation mechanisms.

O ver one-half of the world's plastic is discarded into landfills, where degradation takes tens to thousands of years (1,2). We explored the capacity of microbial consortia to degrade chemically deconstructed polycarbonate (PC) and polyethylene terephthalate (PET) and thermally deconstructed high-density polyethylene (HDPE) and low-density polyethylene (LDPE) (2,3). Metagenomes from two cultures grown using real and anticipated depolymerization products from these materials are reported here.
Five grams of PC and 175 mL of ammonium hydroxide (28 to 30% by weight solution in water) were added to a custom batch reactor and heated to 120°C for 30 min. The product was filtered and neutralized using phosphoric acid. HDPE dissolved in paraffin wax solvent was fed into a custom reactor and heated to 575°C (vapor residence time, ;4 s) to produce pyrolysis oil, as described previously (3,4).
The LIP and SMT cultures are separate enrichments that were inoculated with vermicompost from a farm in Calumet, Michigan, USA (coordinates: 47.211, 288.553), and grown in 90 mL of Bushnell-Haas broth. The LIP culture was amended with 0.25 g of disodium terephthalate, 0.25 g of terephthalamide, 2.5 mL of chemically deconstructed PC, and 0.25 mL of a 1:1:1:1 mixture of C 6 :C 10 :C 16 :C 20 alkenes. The SMT culture was amended with 1 g of disodium terephthalate and 0.74 mL of HDPE pyrolysis oil. Cultures were grown aerobically at 30°C in a shaking incubator. Ten milliliters of culture was transferred to 90 mL of fresh medium every 14 days (LIP) or 7 days (SMT). After growth for 10 weeks (LIP) or 7 weeks (SMT), 40 mL of culture was harvested for DNA extraction using the FastDNA Spin kit for soil (MP Biomedicals).
The University of Utah High-Throughput Genomics Core Facility (UU-HTGCF) used the Nextera Flex DNA library preparation kit (Illumina) for DNA fragmentation and library preparation and normalization. Libraries were evaluated using a Bioanalyzer DNA 1000 chip kit (Agilent Technologies). Paired-end sequencing (2 Â 150 bp) was performed on an Illumina NovaSeq 6000 system with a NovaSeq S4 reagent kit v1.5 (Illumina). Libraries were multiplexed and pooled into one lane. After demultiplexing and quality assessment were performed by the UU-HTGCF, 88,071,978 raw reads (LIP) and 112,316,479 raw reads (SMT) were obtained. The average read length was 151 bp for both metagenomes.

ACKNOWLEDGMENTS
Funding for this work was provided by the Defense Advanced Research Projects Agency ReSource Program (cooperative agreement HR00112020033).
We This work was performed as part of the Principles of Bioinformatics course (BL2700) at Michigan Technological University.
The views, opinions, and/or findings expressed are those of the authors and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government.