Bacterial contributions to formation of transparent exopolymer particles (TEP) and seasonal trends in coastal waters of Sagami Bay, Japan

Sugimoto, Kugako; Fukuda, Hideki; Baki, Mohammad Abdul; Koike, Isao

doi:10.3354/ame046031

Cited by 40 publications

(36 citation statements)

References 43 publications

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“…Bacteria are known to form TEP or their precursors (Stoderegger and Herndl, 1999;Sugimoto et al, 2007). Due to their affinity to other particles (stickiness), TEP are important for the biological pump (Alldredge et al, 1993;Logan et al, 1995).…”

Section: Bulk Dom Changes: Microbial Consumption and Transformation Omentioning

confidence: 99%

Molecular insights into the microbial formation of marine dissolved organic matter: recalcitrant or labile?

et al. 2014

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Abstract. The degradation of marine dissolved organic matter (DOM) is an important control variable in the global carbon cycle. For our understanding of the kinetics of organic matter cycling in the ocean, it is crucial to achieve a mechanistic and molecular understanding of its transformation processes. A long-term microbial experiment was performed to follow the production of non-labile DOM by marine bacteria. Two different glucose concentrations and dissolved algal exudates were used as substrates. We monitored the bacterial abundance, concentrations of dissolved and particulate organic carbon (DOC, POC), nutrients, amino acids and transparent exopolymer particles (TEP) for 2 years. The molecular characterization of extracted DOM was performed by ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) after 70 days and after ∼ 2 years of incubation. Although glucose quickly degraded, a non-labile DOC background (5-9 % of the initial DOC) was generated in the glucose incubations. Only 20 % of the organic carbon from the algal exudate degraded within the 2 years of incubation. The degradation rates for the nonlabile DOC background in the different treatments varied between 1 and 11 µmol DOC L −1 year −1 . Transparent exopolymer particles, which are released by microorganisms, were produced during glucose degradation but decreased back to half of the maximum concentration within less than 3 weeks (degradation rate: 25 µg xanthan gum equivalents L −1 d −1 ) and were below detection in all treatments after 2 years. Additional glucose was added after 2 years to test whether labile substrate can promote the degradation of background DOC (co-metabolism; priming effect). A priming effect was not observed but the glucose addition led to a slight increase of background DOC. The molecular analysis demonstrated that DOM generated during glucose degradation differed appreciably from DOM transformed during the degradation of the algal exudates. Our results led to several conclusions: (i) based on our experimental setup, higher substrate concentration resulted in a higher concentration of nonlabile DOC; (ii) TEP, generated by bacteria, degrade rapidly, thus limiting their potential contribution to carbon sequestration; (iii) the molecular signatures of DOM derived from algal exudates and glucose after 70 days of incubation differed strongly from refractory DOM. After 2 years, however, the molecular patterns of DOM in glucose incubations were more similar to deep ocean DOM whereas the degraded exudate was still different.

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Section: Bulk Dom Changes: Microbial Consumption and Transformation Omentioning

confidence: 99%

Molecular insights into the microbial formation of marine dissolved organic matter: recalcitrant or labile?

et al. 2014

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“…Transparent exopolymer particles (TEP) merge the two properties of (1) being retained onto 0.4 mm membrane filters and (2) being stainable by Alcian Blue, a specific dye for acidic (-COO À ) or sulphated (-O-SO 3 À ) reactive groups of carbohydrates (Alldredge et al, 1993). Several studies indicate that TEP are natural constituents of the bulk particulate matter in marine (Passow and Alldredge, 1995b;Mari and Kiorboe, 1996;Krembs and Engel, 2001;Garcia et al, 2002;Engel, 2004;Brussaard et al, 2005;Radic et al, 2005;Shackelford and Cowen, 2006;Prieto et al, 2006;Sugimoto et al, 2007) (Logan et al, 1995;Grossart et al, 1997;Berman and Viner-Mozzini, 2001;Arruda-Fatibello et al, 2004) ecosystems. Most of the field sites where TEP have been described so far were dominated by diatoms, dinoflagellates or cyanobacteria.…”

Section: Introductionmentioning

confidence: 99%

Abundance and size distribution of transparent exopolymer particles (TEP) in a coccolithophorid bloom in the northern Bay of Biscay

Harlay

Bodt

Engel

et al. 2009

Deep Sea Research Part I: Oceanographic Research Papers

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“…Heterotrophic organisms such as eubacteria can also be important in production (e.g., Passow, 2002b;Sugimoto et al, 2007), decomposition (e.g., Passow et al, 2001), and transformation (e.g., Gärdes et al, 2011;Yamada et al, 2013) processes of TEP. Although the present study suggests that the main TEP producer was likely phytoplankton as described above, bacteria abundance was significantly correlated with not only TEP concentration but also Chl a concentration.…”

Section: Discussion Factors Controlling Tep Levels In Oyashio Regionmentioning

confidence: 99%

“…The strain was sterilized in f/2 medium (Guillard and Ryther, 1962;Guillard, 1975) with penicillin and streptomycin (25 U mL −1 of penicillin and 25 µg mL −1 of streptomycin, 17-603E, Lonza Group Ltd., Switzerland) following the methods of Sugimoto et al (2007). For the culture experiment, salinity of the medium was adjusted to 33.0, which is a typical value of surface Oyasho waters in spring (e.g., Hattori-Saito et al, 2010).…”

Section: Tep Production By the Oyashio Diatom Thalassiosira Nordenskimentioning

confidence: 99%

Dynamics and Origin of Transparent Exopolymer Particles in the Oyashio Region of the Western Subarctic Pacific during the Spring Diatom Bloom

2017

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The seasonal biological drawdown of the partial pressure of CO 2 (pCO 2 ) in the surface waters of the Oyashio region of the western subarctic Pacific is one of the greatest among the world's oceans. This is attributable to spring diatom blooms. Transparent exopolymer particles (TEPs) are known to affect efficiency of the biological carbon pump, and higher TEP levels are frequently associated with massive diatom blooms. However, TEP dynamics in the Oyashio region remain unclear. We investigated the TEP distribution from three cruises during the spring diatom bloom periods in 2010 and 2011. TEP concentrations varied from < 15 to 196 ± 71 µg xanthan gum equiv. L −1 above 300 m and generally declined with depth. Vertical TEP concentrations were significantly related not only to chlorophyll a concentrations but also to bacterial abundance. Average TEP concentrations within the mixed layer (> 30 m) were significantly higher during the bloom (155 ± 12 µg xanthan gum equiv. L −1 ) than in the post-bloom phase (90 ± 32 µg xanthan gum equiv. L −1 ). In contrast, bacteria abundance within the mixed layer changed little during the bloom to post-bloom phases. These results suggest that the abundance of phytoplankton greatly contributed to dynamics of the TEP distribution. To evaluate the ability of the phytoplankton to produce TEP, an axenic strain of the diatom Thalassiosira nordenskioeldii, which is a representative species of Oyashio blooms, was examined within a batch culture system. Cell abundance-normalized TEP and dissolved organic carbon (DOC) production rates changed simultaneously with growth of the strain. Although these production rates were significantly higher in the stationary phase than in the exponential growth period, values of the TEP/DOC ratio changed little throughout incubation. These findings suggest that TEP production in the Oyashio region may be enhanced by an increase in DOC production from spring diatoms.

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Bacterial contributions to formation of transparent exopolymer particles (TEP) and seasonal trends in coastal waters of Sagami Bay, Japan

Cited by 40 publications

References 43 publications

Molecular insights into the microbial formation of marine dissolved organic matter: recalcitrant or labile?

Molecular insights into the microbial formation of marine dissolved organic matter: recalcitrant or labile?

Abundance and size distribution of transparent exopolymer particles (TEP) in a coccolithophorid bloom in the northern Bay of Biscay

Dynamics and Origin of Transparent Exopolymer Particles in the Oyashio Region of the Western Subarctic Pacific during the Spring Diatom Bloom

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