Evidence for selective bacterial community structuring on microplastics

Abstract

In aquatic ecosystems, microplastics are a relatively new anthropogenic substrate that can readily be colonized by biofilm-forming organisms. To examine the effects of substrate type on microbial community assembly, we exposed ambient Baltic bacterioplankton to plastic substrates commonly found in marine environments (polyethylene, polypropylene and polystyrene) as well as native (cellulose) and inert (glass beads) particles for 2 weeks under controlled conditions. The source microbial communities and those of the biofilms were analyzed by Illumina sequencing of the 16S rRNA gene libraries. All biofilm communities displayed lower diversity and evenness compared with the source community, suggesting substrate-driven selection. Moreover, the plastics-associated communities were distinctly different from those on the non-plastic substrates. Whereas plastics hosted greater than twofold higher abundance of Burkholderiales, the non-plastic substrates had a significantly higher proportion of Actinobacteria and Cytophagia. Variation in the community structure, but not the cell abundance, across the treatments was strongly linked to the substrate hydrophobicity. Thus, microplastics host distinct bacterial communities, at least during early successional stages.

Microplastic surface properties affect bacterial colonization in freshwater

“…Thus, A. calcoaceticus has a strategy of aggregating with other bacterial species and forming biofilms to colonize surfaces to compensate for the lack of flagella . Burkolderia cepacia are monotrichously flagellated and modify anthropogenic surfaces they colonize . Our results showed that after 8 weeks, E. coli and B. cepacia were relatively more abundant on most surfaces than A. calcoaceticus .…”

“…Production of EPS differs among bacterial species; however, colonization is affected by the hydrophobic nature and surface roughness of microplastics [20]. Bacterial biofilm and EPS production varies according to surface hydrophobicity of plastics and other anthropogenic materials [20]. Our study demonstrates that bacterial EPS thickness was speciesspecific but was also affected by physicochemical properties of different microplastics.…”

“…Collectively, these results demonstrate the importance of plastic physicochemical properties to bacterial colonization. Surfaces of PE and PS are negatively charged, while PP has been shown to be neutral [15,20]. The cell walls of the bacteria used in this study are negatively charged [20].…”

Soil pH and temperature regulate assembly processes of abundant and rare bacterial communities in agricultural ecosystems

“…Homogenizing selection, estimated by null model analysis, was predicted to have played a major role in the assembly of soil microbial communities, while dispersal limitation was a dominant factor structuring mineral‐associated communities in a rhizosphere microcosm (Whitman et al ., ). Moreover, Ogonowski and colleagues () provided experimental evidences for the significant effect of selection process in the structuring of biofilm microbial community assemblages and demonstrated that differences in biofilm community structure were strongly related to the variation in substrate hydrophobicity.…”

Microbial Colonization in Marine Environments: Overview of Current Knowledge and Emerging Research Topics

“…Ogonowski et al [107] incubated cellulose, glass, PE, PP and PS for two weeks in pre-filtered seawater from the Baltic Sea and found significant differences between plastic and non-plastic substrates, with higher abundance of Burkholderiales within the plastic-associated bacterial flora, while Actinobacteria and Cytophaga prevailed within the bacterial flora attached to non-plastic substrates.…”