Fig 1.
Phylogenetic relationship of Ligia spp. from Nae-do (ND) and Maemul-do (MD) using 16S rRNA sequences.
Sequences of other Ligia spp. were retrieved from GenBank. L. oceanica was used as the out-group. The phylogenetic tree of the aligned sequences was constructed using the neighbor-joining method with the Kimura 2-parameter model of the MEGA software (version 11.0.13).
Fig 2.
Observed species (operational taxonomic unit counts), Chao1, ACE, Shannon, Simpson, and pielou indices in individual samples from the ND and EPS-polluted MD sites.
Fig 3.
Hierarchical clustering heatmap analyses.
The relative abundances of the top 10 bacterial phyla were detected using 16S amplicon sequencing from the ND and EPS-polluted MD sites.
Fig 4.
Histogram of the relative abundance of the top 30 different bacterial taxonomic groups at the family level (A) and genus level (B) in the ND and EPS-polluted MD sites.
The y-axis shows the sequence percentage of each species in the total 16S rRNA sequences of each sample.
Fig 5.
Significantly different genera in ND and EPS-polluted MD sites.
A) Linear discriminant analysis (LDA) effect size (LEfSe) performed on the bacterial community relative abundance data (16s amplicon sequencing) and B) shotgun metagenome (percentage of 16S reads) in the ND and EPS-polluted MD sites. LDA scores were calculated using LDA effect size (p< 0.05 using Kruskal–Wallis test), using the linear discriminant analysis to assess the effect size of each differentially abundant bacterial taxa.
Table 1.
Top five members from each taxonomic rank based on normalized proportion per sample.
Means (n = 3) ± standard error of mean are reported for each of the taxonomic assignments.
Fig 6.
Functional gene analysis using shotgun metagenome data and PlasticDB.
Boxplot showing significant differences in the abundance of plastic-degradation genes in microbes after comparing the groups of samples using DEseq2 (p<0.05).
Table 2.
Top 10 plastic-degrading enzymes and microbes detected in Ligia from EPS-polluted MD.
Fig 7.
Kyoto Encyclopedia of Genes and Genome (KEGG) pathways enrichment analysis of the metagenome.
Top 30 Significantly enriched KEGG pathways in the ND metagenomes relative to that in the MD metagenomes.