From waste to resource: Metagenomics uncovers the molecular ecological resources for plastic degradation in estuaries of South China

Lei Zhou; Shilei Sang; Jiajie Li; Yusen Li; Dapeng Wang; Lihong Gan; Zelong Zhao; Jun Wang

doi:10.1016/j.watres.2023.120270

From waste to resource: Metagenomics uncovers the molecular ecological resources for plastic degradation in estuaries of South China

Water Res. 2023 Aug 15:242:120270. doi: 10.1016/j.watres.2023.120270. Epub 2023 Jun 27.

Authors

Lei Zhou¹, Shilei Sang², Jiajie Li¹, Yusen Li³, Dapeng Wang⁴, Lihong Gan¹, Zelong Zhao⁵, Jun Wang⁶

Affiliations

¹ University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China.
² State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, MEE, Guangzhou, 510655, China.
³ University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China; Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning, 530021, China.
⁴ Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning, 530021, China.
⁵ Liaoning Key Lab of Germplasm Improvement and Fine Seed Breeding of Marine Aquatic animals, Liaoning Ocean and Fisheries Science Research Institute, Dalian, 116023, China. Electronic address: zzl2516@163.com.
⁶ University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China. Electronic address: wangjun2016@scau.edu.cn.

PMID: 37392508
DOI: 10.1016/j.watres.2023.120270

Abstract

Estuaries are hotspots of plastic pollution due to accumulated waste from surrounding rivers and coasts. However, the molecular ecological resources that possess plastic-degrading traits and their biogeographic distributions in estuarine waters remain to be elucidated. In this study, we mapped the distribution profiles of plastic-degrading genes (PDGs) in 30 subtropical estuaries in China based on metagenomic sequencing. A total of 41 PDG subtypes were observed in these estuaries. The Pearl River Estuary had higher diversity and abundance of PDGs than the east and west region estuaries. Genes for degrading synthetic heterochain and natural plastics were the most diverse and abundant types, respectively. The abundance of synthetic PDGs was significantly higher in estuaries affected by intense anthropogenic activities. Further binning strategies revealed diverse microbes with plastic-degrading ability in these estuaries. Rhodobacteraceae, a dominant plastic-degrading bacterial family, primarily carried PDGs for degrading natural plastics. Pseudomonas veronii carrying diverse PDGs was identified, which may be of value for further technical improvement of plastic degradation. In addition, phylogenetic and structural analyses of 19 putative 3HV dehydrogenases, the most diverse and abundant DPGs, showed inconsistent evolution with their hosts, but different sequences were conserved with consistent key functional amino acids. A potential biodegradation pathway for polyhydroxybutyrate by Rhodobacteraceae was proposed. The result implied that plastic-degrading functions are widely distributed in estuarine waters and metagenomics could be used as a promising screening tool for large-scale profiling of plastic-degrading potential in the natural environment. Our findings have important implications and provide potential molecular ecological resources for developing plastic waste removal technologies.

Keywords: 3HV dehydrogenase; Metagenome assembled genome; Metagenomics; Plastic-degrading genes; Subtropical estuary.

MeSH terms

China
Environmental Monitoring
Estuaries*
Metagenomics
Phylogeny
Plastics
Rivers / chemistry
Water Pollutants, Chemical* / analysis

Substances

Plastics
polyhydroxybutyrate
Water Pollutants, Chemical