Ugly ducklings—the dark side of plastic materials in contact with potable water

Abstract

Bath toys pose an interesting link between flexible plastic materials, potable water, external microbial and nutrient contamination, and potentially vulnerable end-users. Here, we characterized biofilm communities inside 19 bath toys used under real conditions. In addition, some determinants for biofilm formation were assessed, using six identical bath toys under controlled conditions with either clean water prior to bathing or dirty water after bathing. All examined bath toys revealed notable biofilms on their inner surface, with average total bacterial numbers of 5.5 × 106 cells/cm2 (clean water controls), 9.5 × 106 cells/cm2 (real bath toys), and 7.3 × 107 cells/cm2 (dirty water controls). Bacterial community compositions were diverse, showing many rare taxa in real bath toys and rather distinct communities in control bath toys, with a noticeable difference between clean and dirty water control biofilms. Fungi were identified in 58% of all real bath toys and in all dirty water control toys. Based on the comparison of clean water and dirty water control bath toys, we argue that bath toy biofilms are influenced by (1) the organic carbon leaching from the flexible plastic material, (2) the chemical and biological tap water quality, (3) additional nutrients from care products and human body fluids in the bath water, as well as, (4) additional bacteria from dirt and/or the end-users’ microbiome. The present study gives a detailed characterization of bath toy biofilms and a better understanding of determinants for biofilm formation and development in systems comprising plastic materials in contact with potable water.

Fungi in aquatic ecosystems

“…Furthermore, humans continuously introduce terrestrial matter and waste products such as microplastics and other anthropogenic debris into natural aquatic ecosystems in an unprecedented scale. These pollutants can represent new artificial surfaces for colonization of fungal communities 118 , whose diversity and structure are different from the natural assemblages 119 . These novel habitats are provoking the development of complex interactions between autotrophic and heterotrophic organisms, with profound consequences for functionality and evolution of aquatic ecosystems 120 , e.g., via gene exchange of functional genes.…”

Critical Assessment of Methods to Quantify Biofilm Growth and Evaluate Antibiofilm Activity of Host Defence Peptides

“…Besides the physical barrier of the polymeric matrix, the bacteria within a biofilm undergo transcriptional changes to activate communication via quorum sensing and respond to the perceived stringent stressors and trigger resistance mechanisms that protect the cells from antibiotics and other antimicrobial threats [ 1 ]. Biofilms are ubiquitous in our environment [ 2 , 3 , 4 ], and it has been proposed that this is the natural growth state of bacteria [ 5 ]. Unfortunately, bacteria within biofilms are a significant concern as they are responsible for up to 65% of infections in humans [ 6 , 7 ] and are highly adaptively resistant (10–1000-fold) to conventional antibiotics [ 8 ].…”

Resource or waste? A perspective of plastics degradation in soil with a focus on end-of-life options

“…It is not possible to obtain reliable estimates of the amount of plastic debris that reaches the soil environment, but the quantities are nevertheless quite substantial. Compared to the hydrosphere, for which there are quantification methods, detailed and large-scale studies, and abundant studies on the degradation of these polymers in water (either freshwaters or seawaters) (Jambeck et al., 2015; Neu et al., 2018), on the pedosphere these information are rare, scattered and not homogeneous. The effort of this review is to collect and systematize existing knowledge on different plastic polymers and their behaviour in soils.…”