Polystyrene influences bacterial assemblages in Arenicola marina-populated aquatic environments in vitro

Plastic is ubiquitous in global oceans and constitutes a newly available habitat for surface-associated bacterial assemblages. Microplastics (plastic particles <5 mm) are especially susceptible to ingestion by marine organisms, as the size of these particles makes them available also to lower trophic levels. Because many marine invertebrates harbour potential pathogens in their guts, we investigated whether bacterial assemblages on polystyrene are selectively modified during their passage through the gut of the lugworm Arenicola marina and are subsequently able to develop pathogenic biofilms. We also examined whether polystyrene acts as a vector for gut biofilm assemblages after subsequent incubation of the egested particles in seawater. Our results showed that after passage through the digestive tract of A. marina, the bacterial assemblages on polystyrene particles and reference glass beads became more similar, harbouring common sediment bacteria. By contrast, only in the presence of polystyrene the potential symbiont Amphritea atlantica was enriched in the investigated biofilms, faeces, and water. Thus, especially in areas of high polystyrene contamination, this polymer may impact the bacterial composition of different habitats, with as yet unknown consequences for the respective ecosystems.

Katharina Kesy, Sonja Oberbeckmann, Felix Müller, Matthias Labrenz, Environmental Pollution, Volume 219, December 2016, Pages 219–227

The article

Dangerous hitchhikers? Evidence for potentially pathogenic Vibrio spp. on microplastic particles

The taxonomic composition of biofilms on marine microplastics is widely unknown. Recent sequencing results indicate that potentially pathogenic Vibrio spp. might be present on floating microplastics. Hence, these particles might function as vectors for the dispersal of pathogens. Microplastics and water samples collected in the North and Baltic Sea were subjected to selective enrichment for pathogenic Vibrio species. Bacterial colonies were isolated from CHROMagar™Vibrio and assigned to Vibrio spp. on the species level by MALDI-TOF MS (Matrix Assisted Laser Desorption/Ionisation – Time of Flight Mass Spectrometry). Respective polymers were identified by ATR FT-IR (Attenuated Total Reflectance Fourier Transform – Infrared Spectroscopy). We discovered potentially pathogenic Vibrio parahaemolyticus on a number of microplastic particles, e.g. polyethylene, polypropylene and polystyrene from North/Baltic Sea. This study confirms the indicated occurrence of potentially pathogenic bacteria on marine microplastics and highlights the urgent need for detailed biogeographical analyses of marine microplastics.

Inga V. Kirstein, Sidika Kirmizi, Antje Wichel, Alexa Garin-Fernandez, Rene Erler, Martin Löder, Gunnar Gerdts, Marine Environmental Research, Volume 120, September 2016, Pages 1–8

The article

Biofilms on Plastic Debris and Their Influence on Marine Nutrient Cycling, Productivity, and Hazardous Chemical Mobility

Plastic debris is entering our oceans at an alarming rate and almost instantaneously colonized by a microbial biofilm that is unique from the microbial flora in surrounding waters. Microbial inhabitants on plastic marine debris (PMD) are now known to fluctuate depending upon season, geographic location, substrate, and age. Cursory calculations estimate a range of 1,000–15,000 metric tons of microbial biomass harbored on PMD. Here, we consider the significance and implications of this large amount of microbial metabolic potential that PMD carries and pose future research questions involving the implications of this relatively recent anthropogenic substrate and its diverse microbial inhabitants.

Tracy J. Mincer, Erik R. Zettler, Linda A. Amaral-Zettler, Chapter, Part of the series The Handbook of Environmental Chemistry pp 1-13, May 2016

The chapter