Bacterioplankton growth yield in continuous seawater cultures

Section: Production and Consumption Of Organic Carbon In Reef Watermentioning

confidence: 96%

Organic carbon flux in Shiraho coral reef (Ishigaki Island, Japan)

Harada

Kudo²,

Yamano³

et al. 2002

“…(If bacteria grow at a lower efficiency, as implied by some studies, e.g. Newell et al [1981], Bjarnsen [1986], this percentage of PP utilized by bacteria would be even larger.) This value of bacterial production as 20 % of primary production agrees extremely well with Williams' (1981) earlier assessment and with other direct studies of carbon cycling in lakes and marine systems.…”

Section: Implications For Aquatic Food Websmentioning

confidence: 99%

Bacterial production in fresh and saltwater ecosystems: a cross-system overview

Cole¹,

Findlay²,

Pace³

1988

1,381

979

Heterotrophic bacteria are thought to be important components of aquatic ecosystems in several ways. These bacteria remineralize organic materials and convert some organic material into bacterial biomass. We examined data from 70 studies in which estimates of production of heterotrophic bacterial biomass (bacterial production) were reported for fresh-and saltwater ecosystems. In sediments, bacterial production was sigdicantly (p <0.001), positively correlated to sediment organic C content. Systems which had hlgh rates of benthic primary production (such as coral reefs) had rates of bacterial production greater than those predicted by sediment organic C content alone. In the photic zone of lakes and the ocean, bacterial production was significantly correlated with planktonic primary production, chlorophyll a, or numbers of planktonic bacteria. For all planktonic systems analysed, bacterial production ranged from 0.4 to 150 pg C 1-' d-' and averaged 20 % (median 16.5 %) of planktonic primary production. On an area1 basis for the entire water column, bacterial production ranged from 118 to 2439 mg m-2 d-' and averaged 30 % (median 27 %) of water column primary production. Heterotrophic bacterial production is, thus, a large component of total secondary production and is roughly twice as large as the production of macrozooplankton for a given level of primary production.

“…Nevertheless, it would be desirable to perform all measurements in carbon units and use a direct determination of bacterial carbon production. This approach was taken by Bjernsen (1986b) growing free-living bacteria in continuous cultures fed with filtered seawater from Roskilde Fjord. Bjernsen (1986b) reached much lower estimates of bacterial growth yield (21 %).…”

Section: Bacterial Metabolismmentioning

confidence: 99%

“…This approach was taken by Bjernsen (1986b) growing free-living bacteria in continuous cultures fed with filtered seawater from Roskilde Fjord. Bjernsen (1986b) reached much lower estimates of bacterial growth yield (21 %). His approach was good but some methodological problems may still have remained (e.g.…”

Section: Bacterial Metabolismmentioning

confidence: 99%

Pelagic metabolism in eutrophic coastal waters during a late summer period

Sand‐Jensen¹,

Jensen²,

Marcher³

et al. 1990

We measured phytoplankton and bacterial biomass and production at weekly intervals during summer in water samples from 2 sites in the shallow, eutrophic Roskilde Fjord, Denmark. In addition we measured Oz-uptake on unfiltered water and size-fractions < 100 pm and < 1 pm. Phytoplankton gross production in the water column was 6.2 g O2 m 2 d ' at Stn 1 and was balanced by pelagic community respiration (Rc, 3.8 g 0; m 2 d ' ) and sediment respiration (2.5 g 0; m"' d-l).Phytoplankton gross respiration (3.0 g O2 m 2 d l ) was temporarily exceeded by pelagic community respiration (3.1 g O2 m 2 d ' ) plus sediment respiration (2.0 g 0; m 2 d l ) at Stn 2 where there is additional production by Littoral plant communities. Phytoplankters and bacteria together accounted for 72 to 85 % of Re and zooplankters for the remainder Phytoplankters respired a large proportion (ca 30%) of their gross production and were apparently mainly grazed by benthic suspension feeders. Phytoplankters dominated pelagic respiration (50% of Re) at Stn 1, which has most phytoplankton, while bacteria dominated (44 % of Re) at Stn 2. We ascribe the relatively larger respiratory activity of bacteria at Stn 2 to additional supply of organic matter from littoral plant communities and frequent sediment resuspension. The importance of bacteria in the pelagic food web was supported by other findings. Bacterial biomass approached phytoplankton carbon biomass at Stn 2 and bacterial net production in the water column was 10 % (Stn 1) and 35 " % (Stn 2) of phytoplankton gross production. Bacterial net production and respiration were linearly related in the bacterial size-fraction (< 1 pm) with a bacterial growth yield of 47 %. We argue that the conversion factors applied to calculate bacterial net production and the mean growth yield attained are reasonable values considering the other measurements of pelagic carbon pools and processes.