Do transparent exopolymeric particles (TEP) affect the toxicity of nanoplastics on Chaetoceros neogracile?

ABSTRACT Viruses on organic aggregates such as transparent exopolymeric particles (TEP) are not well investigated. The number of TEP-attached viruses was assessed along trophic gradients in the southwestern lagoon of New Caledonia by determining the fraction of viruses removed after magnetic isolation of TEP. In order to isolate TEP magnetically, TEP were formed in the presence of magnetic beads from submicrometer precursors collected along the trophic gradients. The mixed aggregates of TEP-beads-viruses were removed from solution with a magnetic field. The percentage of viruses associated with newly formed TEP averaged 8% (range, 3 to 13%) for most of the stations but was higher (ca. 30%) in one bay characterized by the low renewal rate of its water mass. The number of viruses (N) attached to TEP varied as a function of TEP size (d [in micrometers]) according to the formulas N = 100d 1.60 and N = 230d 1.75, respectively, for TEP occurring in water masses with short (i.e., <40 days) and long (i.e., >40 days) residence times. These two relationships imply that viral abundance decreases with TEP size, and they indicate that water residence time influences viral density and virus-bacterium interactions within aggregates. Our data suggest that the fraction of viruses attached to TEP is highest in areas characterized by a low renewal rate of the water mass and can constitute at times a significant fraction of total virus abundance. Due to the small distance between viruses and hosts on TEP, these particles may be hot spots for viral infection.

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Direct Role of Transparent Exopolymeric Particles (TEP) on Membrane Fouling of Microand Ultrafiltration

Procedia Engineering ◽

10.1016/j.proeng.2012.08.478 ◽

2012 ◽

Vol 44 ◽

pp. 537-538

Author(s):

V. Discart ◽

M.R. Bilad ◽

D. Vandamme ◽

I. Foubert ◽

K. Muylaert ◽

...

Keyword(s):

Membrane Fouling ◽

Direct Role ◽

Transparent Exopolymeric Particles

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Transparent exopolymeric particles' distribution in the northern Adriatic and their relation to microphytoplankton biomass and composition

The Science of The Total Environment ◽

10.1016/j.scitotenv.2005.09.013 ◽

2005 ◽

Vol 353 (1-3) ◽

pp. 151-161 ◽

Cited By ~ 35

Author(s):

Tomislav Radić ◽

Romina Kraus ◽

Dragica Fuks ◽

Jadranka Radić ◽

Osvin Pečar

Keyword(s):

Northern Adriatic ◽

Transparent Exopolymeric Particles

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Dynamics of transparent exopolymer particles (TEP) during the VAHINE mesocosm experiment in the New Caledonia lagoon

10.5194/bg-2015-612 ◽

2016 ◽

Cited By ~ 4

Author(s):

I. Berman-Frank ◽

D. Spungin ◽

E. Rahav ◽

F. Van Wambeke ◽

K. Turk-Kubo ◽

...

Keyword(s):

Bacterial Production ◽

Temporal Dynamics ◽

New Caledonia ◽

Inorganic Phosphorus ◽

Second Phase ◽

Physical Processes ◽

Dissolved Carbon ◽

Spatial And Temporal Dynamics ◽

Transparent Exopolymeric Particles ◽

Diazotrophic Growth

Abstract. In the marine environment, transparent exopolymeric particles (TEP) produced from abiotic and biotic sources link the particulate and dissolved carbon pools and are essential vectors enhancing vertical carbon flux. We characterized spatial and temporal dynamics of TEP during the VAHINE experiment that investigated the fate of diazotroph derived nitrogen and carbon in three, replicate, dissolved inorganic phosphorus (DIP)-fertilized 50 m3 enclosures in an oligotrophic New Caledonian lagoon. During the 23 days of the experiment, we did not observe any depth dependent changes in TEP concentrations in the three sampled-depths (1, 6, 12 m). TEP carbon (TEP-C) content per mesocosm averaged 28.9 ± 9.3% and 27.0 ± 7.2% of TOC in the mesocosms and surrounding lagoon respectively and was strongly and positively coupled with TOC during P2. TEP concentrations declined for the first 9 days after DIP fertilization (P1 = days 5-14) and then gradually increased during the second phase (P2 = days 15-23). Temporal changes in TEP concentrations paralleled the growth and mortality rates of the diatom-diazotroph association of Rhizosolenia and Richelia that predominated the diazotroph community during P1. By P2, increasing total primary and heterotrophic bacterial production consumed the supplemented P and reduced availability of DIP. For this period, TEP concentrations were negatively correlated with DIP availability and turnovertime of DIP (TDIP) while positively associated with enhanced alkaline phosphatase activity (APA) that occurs when the microbial populations are P-stressed. During P2, increasing bacterial production (BP) was positively correlated with higher TEP concentrations which were also coupled with the increased growth rates and aggregation of the unicellular UCYN-C diazotrophs which bloomed during this period. We conclude that the composite processes responsible for the formation and breakdown of TEP yielded a relatively stable TEP pool available as both a carbon source and facilitating aggregation and flux throughout the experiment. TEP was probably mostly influenced by abiotic physical processes during P1 while biological activity (BP, diazotrophic growth and aggregation, export production) mainly impacted TEP concentrations during P2 when DIP-availability was limited.

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