Variation in the relative abundance of bacterial 16S rRNA genes. The data are based on bacterial 16S rRNA genes amplified from DNA extracted from LDPE microplastics in sediments sampled over time. LDPE fragments were sampled in triplicate over time [immediately (Imm.), after 6 hours (hrs) and on days (D) 1, 2, 4, 7 and 14)] from microcosms containing sediments from three sites (SP1, SP2 and WB, as indicated). Abundances are expressed as 16S rRNA genes per mm2 of LDPE. Error bars represent one standard error (n = 3). Gene numbers were calculated from the following standard curve: r
2 = 0.979, y intercept = 42.6, slope = -4.64, E (amplification efficiency) =-64%, and C
t cut-off of 28.7.