Heterotrophic activities of bacterioplankton and bacteriobenthos

1981 ◽  
Vol 27 (3) ◽  
pp. 259-266 ◽  
Author(s):  
J. A. Chocair ◽  
L. J. Albright
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Surface Sediments ◽  
Marine Waters ◽  
Bacterial Colony ◽  
Colony Forming Units ◽  
Order Of Magnitude ◽  
Specific Activities ◽  
Active Bacteria ◽  
Coastal British Columbia

Several marine waters and surface sediments of coastal British Columbia were analyzed and compared for bacterial colony forming units (CFU) and numbers of active bacteria (NAB) as indicated by microautoradiography, glucose and alanine heterotrophic activities, and dissolved (DOC) and particulate organic carbon (POC). Bacterial numbers (CFU, NAB) were usually much greater (by several orders of magnitude) in surface sediments than in overlying waters. DOC and POC were also generally greater in surface sediments than in overlying waters, often by as much as one order of magnitude. Both glucose and alanine heterotrophic potentials were greater in surface sediments; however, on a per active cell (NAB) basis, no significant differences were noted between the glucose-specific activities of the bacteria of the surface sediments and overlying waters. The data suggest that these surface sediments carry greater standing crops of bacteria than overlying waters without significant decreases in glucose-specific activities.

Seasonal changes in heterotrophic bacteria under fast ice near Syowa station, Antarctica

1989 ◽  
Vol 35 (2) ◽  
pp. 329-333 ◽  
Author(s):  
Hiroo Satoh ◽  
Kimio Fukami ◽  
Kentaroo Watanabe ◽  
Eiji Takahashi
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Seasonal Changes ◽  
Heterotrophic Bacteria ◽  
Seasonal Succession ◽  
Austral Spring ◽  
Syowa Station ◽  
Colony Forming Units ◽  
Algal Assemblages ◽  
Fast Ice

Seasonal changes in the number of heterotrophic bacteria and the species composition of their communities were investigated in the fast ice area of Syowa station (69°00′S, 39°35′E), from May 1983 to January 1984. Numbers of heterotrophic bacteria under the fast ice began to increase in October and the maximum number of colony-forming units/mL (2.4 × 102) were obtained in late December. The changes in bacterial numbers coincided well with those of particulate organic carbon, suggesting that the growth of heterotrophic bacteria depends on the supply of particulate organic carbon from ice algal assemblages which grow rapidly at the bottom of sea ice during the austral spring. Vibrionaceans in the communities in September accounted for as much as 35% of the isolates, whereas in December, they were not detected at all. These results indicate that there is a seasonal succession in the bacterial communities between September and December.Key words: heterotrophic bacteria, vibrionaceans, fast ice, Antarctica.

Particulate organic carbon (POC) in surface sediments of the Baltic Sea

2010 ◽  
Vol 31 (3) ◽  
pp. 175-188 ◽  
Author(s):  
Thomas Leipe ◽  
Franz Tauber ◽  
Henry Vallius ◽  
Joonas Virtasalo ◽  
Szymon Uścinowicz ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Baltic Sea ◽  
Particulate Organic Carbon ◽  
Surface Sediments ◽  
The Baltic Sea ◽  
The Baltic

scholarly journals Evidence for tight coupling between active bacteria and particulate organic carbon during seasonal stratification of Lake Michigan

2001 ◽  
Vol 46 (5) ◽  
pp. 1202-1208 ◽  
Author(s):  
Benjamin Van Mooy ◽  
Barbara MacGregor ◽  
David Hollander ◽  
Ken Nealson ◽  
David Stahl
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Lake Michigan ◽  
Tight Coupling ◽  
Active Bacteria ◽  
Seasonal Stratification

The Carbon:²³⁴Thorium ratios of sinking particles in the California Current Ecosystem 2: Examination of a thorium sorption, desorption, and particle transport model

2019 ◽  
Author(s):  
Michael Stukel ◽  
Thomas Kelly
Keyword(s):  
Organic Carbon ◽  
Water Column ◽  
Particulate Organic Carbon ◽  
Transport Model ◽  
California Current ◽  
In Situ Measurements ◽  
Power Law Distribution ◽  
Sinking Particles ◽  
Organic Carbon Concentration

Thorium-234 (234Th) is a powerful tracer of particle dynamics and the biological pump in the surface ocean; however, variability in carbon:thorium ratios of sinking particles adds substantial uncertainty to estimates of organic carbon export. We coupled a mechanistic thorium sorption and desorption model to a one-dimensional particle sinking model that uses realistic particle settling velocity spectra. The model generates estimates of 238U-234Th disequilibrium, particulate organic carbon concentration, and the C:234Th ratio of sinking particles, which are then compared to in situ measurements from quasi-Lagrangian studies conducted on six cruises in the California Current Ecosystem. Broad patterns observed in in situ measurements, including decreasing C:234Th ratios with depth and a strong correlation between sinking C:234Th and the ratio of vertically-integrated particulate organic carbon (POC) to vertically-integrated total water column 234Th, were accurately recovered by models assuming either a power law distribution of sinking speeds or a double log normal distribution of sinking speeds. Simulations suggested that the observed decrease in C:234Th with depth may be driven by preferential remineralization of carbon by particle-attached microbes. However, an alternate model structure featuring complete consumption and/or disaggregation of particles by mesozooplankton (e.g. no preferential remineralization of carbon) was also able to simulate decreasing C:234Th with depth (although the decrease was weaker), driven by 234Th adsorption onto slowly sinking particles. Model results also suggest that during bloom decays C:234Th ratios of sinking particles should be higher than expected (based on contemporaneous water column POC), because high settling velocities minimize carbon remineralization during sinking.

scholarly journals Differences in susceptibility of marine bacterial communities to metal pyrithiones, their degradation compounds and organotin antifouling biocides

2019 ◽  
Vol 99 (5) ◽  
pp. 1033-1039
Author(s):  
Madoka Ohji ◽  
Hiroya Harino ◽  
William John Langston
Keyword(s):  
Life History ◽  
Degradation Product ◽  
Bacterial Communities ◽  
Degradation Products ◽  
High Susceptibility ◽  
Zinc Pyrithione ◽  
Bacterial Colony ◽  
Indigenous Bacteria ◽  
Antifouling Biocides ◽  
Colony Forming Units

AbstractThe susceptibility of marine bacterial communities to copper pyrithione (CuPT2), zinc pyrithione (ZnPT2) and their degradation product is described and toxicities of these relatively new antifouling biocides compared with those of their harmful organotin (OT) predecessors, tributyltin (TBT) and triphenyltin (TPT). These biocides were added to agar at concentrations of 0, 0.01, 0.1, 1 and 10 mg l−1and coastal seawater including indigenous bacteria added to each batch of agar solution. The number of bacterial colony forming units (CFU) was measured after 7 days culture. Relative CFU (as a percentage of control) was more than 80% at a concentration of 0.01 mg l−1of each compound, except for TBT. Relative CFU decreased as a function of dose of each biocide, although concentration-dependent changes in rate of CFU were relatively low during exposure to degradation products of CuPT2and ZnPT2, pyridineN-oxide (PO) and pyridine-2-sulphonic acid (PSA). Based on comparisons of EC50, TBT was the most bacterio-toxic of the tested compounds (0.2 mg l−1), marginally more so than CuPT2(0.3 mg l−1). Interestingly, EC50values of degradation products of CuPT2and ZnPT2, 2-mercaptopyridineN-oxide (HPT) and 2,2′-dithio-bispyridineN-oxide (PT2) were 0.8 and 0.5 mg l−1, respectively, lower than that of the parent chemical, ZnPT2(1.4 mg l−1). The EC50of PT2was also lower than that of TPT (0.7 mg l−1), implying higher toxicity. Given the overlapping toxicity ranges, these results suggest that marine bacterial communities experience comparably high susceptibility to metal PTs and OTs during their life history.

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