Phylogenetic Diversity of Microbial Communities from the Surface of Polyethylene Terephthalate Materials Exposed to Different Water Environments

The goal of the present work was to investigate the composition of microbial communities developing on polyethylene terephthalate (PET) samples immersed in aqueous media of various origin (marine, freshwater, and industrial; the latter was periodically treated with an antimicrobial agent) in three different climatic zones. High-throughput sequencing of the V3-V4 region of the 16S rRNA gene was used to obtain gene libraries for each of the samples. Members of the phyla Bacteroidetes, Gammaproteobacteria, and Alphaproteobacteria predominated in the libraries from all three groups of the samples. However, the quantitative ratios of both the dominant and the minor groups in the libraries were different, and within the groups the ratios depended on exposure time and antimicrobial treatment. Both the groups of libraries from the samples of different origin and individual communities within the groups exhibited differences at the genus level. The functional characteristics of prokaryotes in the 16S rRNA gene libraries were predicted using iVikodak. Microbial communities of industrial water, in which members of the genera Pseudomonas and Acidovorax were detected in silico were shown to be potentially capable of degrading PET samples; these organisms possess the enzymes for catabolism of terephthalic acid, the intermediate metabolite of this process. Photomicrography confirmed local PET degradation after exposure in industrial water, while no PET degradation was observed in seawater.