Abstract：
The exploitation of exciting features of plastics for diverse applications has resulted in significant plastic waste generation, which negatively impacts environmental compartments, metabolic processes, and the well-being of aquatic ecosystems biota. A shotgun metagenomic approach was deployed to investigate the microbial consortia, degradation pathways, and enzyme systems involved in the degradation of plastics in a tropical lentic pond sediment (APS). Functional annotation of the APS proteome (ORFs) using the PlasticDB database revealed annotation of 1015 proteins of enzymes such as depolymerase, esterase, lipase, hydrolase, nitrobenzylesterase, chitinase, carboxylesterase, polyesterase, oxidoreductase, polyamidase, PETase, MHETase, laccase, alkane monooxygenase, among others involved in the depolymerization of the plastic polymers. It also revealed that polyethylene glycol (PEG), polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polyethylene terephthalate (PET), and nylon have the highest number of annotated enzymes. Further annotation using the KEGG GhostKOALA revealed that except for terephthalate, all the other degradation products of the plastic polymers depolymerization such as glyoxylate, adipate, succinate, 1,4-butanediol, ethylene glycol, lactate, and acetaldehyde were further metabolized to intermediates of the tricarboxylic acid cycle. Taxonomic characterization of the annotated proteins using the AAI Profiler and BLASTP revealed that Pseudomonadota members dominate most plastic types, followed by Actinomycetota and Acidobacteriota. The study reveals novel plastic degraders from diverse phyla hitherto not reported to be involved in plastic degradation. This suggests that plastic pollution in aquatic environments is prevalent with well-adapted degrading communities and could be the silver lining in mitigating the impacts of plastic pollution in aquatic environments.
摘要：
塑料在不同应用中令人兴奋的特性的开发导致了大量的塑料废物的产生，对环境隔间产生负面影响，代谢过程，以及水生生态系统生物群的福祉。采用shot弹枪宏基因组方法来研究微生物联盟，降解途径，和酶系统参与热带药池沉积物（APS）中塑料的降解。使用PlasticDB数据库对APS蛋白质组（ORFs）的功能注释揭示了1015种酶的蛋白质，例如解聚酶，酯酶,脂肪酶,水解酶，硝基苄基酯酶，几丁质酶，羧酸酯酶，聚酯酶,氧化还原酶,聚酰胺酶,PETase,MHETase,漆酶,烷烃单加氧酶，其中涉及塑料聚合物的解聚。它还揭示了聚乙二醇(PEG)，聚羟基链烷酸酯(PHA),聚羟基丁酸酯（PHB），聚乳酸(PLA),聚己二酸对苯二甲酸丁二醇酯(PBAT)，聚对苯二甲酸乙二醇酯(PET),和尼龙具有最高数目的注解酶。使用KEGGGhostKOALA的进一步注释表明，除了对苯二甲酸酯，塑料聚合物解聚的所有其他降解产物，如乙醛酸，己二酸,琥珀酸盐,1,4-丁二醇,乙二醇,乳酸，和乙醛进一步代谢为三羧酸循环的中间体。使用AAIProfiler和BLASTP对注释蛋白质的分类学表征表明，Pseudomonadota成员主导大多数塑料类型，其次是放线菌和酸杆菌。该研究揭示了迄今为止尚未报道过的各种门的新型塑料降解剂与塑料降解有关。这表明，水生环境中的塑料污染在适应良好的降解社区中普遍存在，可能是减轻塑料污染对水生环境影响的一线希望。
