scholarly journals Fe and C co-limitation of heterotrophic bacteria in the naturally fertilized region off the Kerguelen Islands

2015 ◽  
Vol 12 (6) ◽  
pp. 1983-1992 ◽  
Author(s):  
I. Obernosterer ◽  
M. Fourquez ◽  
S. Blain
Keyword(s):  
Trace Metal ◽  
Bacterial Production ◽  
Bacterial Abundance ◽  
Heterotrophic Bacteria ◽  
Kerguelen Islands ◽  
High Nutrient ◽  
Limiting Nutrient ◽  
Heterotrophic Metabolism ◽  
Heterotrophic Production

Abstract. It has been univocally shown that iron (Fe) is the primary limiting nutrient for phytoplankton metabolism in high-nutrient, low-chlorophyll (HNLC) waters, yet the question of how this trace metal affects heterotrophic microbial activity is far less understood. We investigated the role of Fe for bacterial heterotrophic production and growth at three contrasting sites in the naturally Fe-fertilized region east of the Kerguelen Islands and at one site in HNLC waters during the KEOPS2 (Kerguelen Ocean and Plateau Compared Study 2) cruise in spring 2011. We performed dark incubations of natural microbial communities amended either with iron (Fe, as FeCl3) or carbon (C, as trace-metal clean glucose), or a combination of both, and followed bacterial abundance and heterotrophic production for up to 7 days. Our results show that single and combined additions of Fe and C stimulated bulk and cell-specific bacterial production at the Fe-fertilized sites, while in HNLC waters only combined additions resulted in significant increases in these parameters. Bacterial abundance was enhanced in two out of the three experiments performed in Fe-fertilized waters but did not respond to Fe or C additions in HNLC waters. Our results provide evidence that both Fe and C are present at limiting concentrations for bacterial heterotrophic activity in the naturally fertilized region off the Kerguelen Islands in spring, while bacteria were co-limited by these elements in HNLC waters. These results shed new light on the role of Fe in bacterial heterotrophic metabolism in regions of the Southern Ocean that receive variable Fe inputs.

scholarly journals Fe and C co-limitation of heterotrophic bacteria in the naturally fertilized region off Kerguelen Islands

2014 ◽  
Vol 11 (11) ◽  
pp. 15733-15752 ◽  
Author(s):  
I. Obernosterer ◽  
M. Fourquez ◽  
S. Blain
Keyword(s):  
Trace Metal ◽  
Heterotrophic Bacteria ◽  
Surface Mixed Layer ◽  
Kerguelen Islands ◽  
Uptake Rates ◽  
Fe Uptake ◽  
Limiting Nutrient ◽  
Heterotrophic Metabolism ◽  
Heterotrophic Production

Abstract. It has univocally been shown that iron (Fe) is the primary limiting nutrient for phytoplankton metabolism in High Nutrient Low Chlorophyll (HNLC) oceans, yet, the question of how this trace metal affects heterotrophic microbial activity is far less understood. We investigated the role of Fe for bacterial heterotrophic production and growth at three contrasting sites in the naturally Fe-fertilized region east of Kerguelen Islands and at one site in HNLC waters during the KEOPS2 (Kerguelen Ocean and Plateau Compared Study 2) cruise in spring 2011. We performed dark incubations of natural microbial communities amended either with iron (Fe, as FeCl3), or carbon (C, as trace-metal clean glucose), or a combination of both, and followed bacterial abundance and heterotrophic production for up to 7 days. Our results show that single and combined additions of Fe and C stimulated bulk and cell-specific bacterial production at all sites, while bacterial growth was enhanced only in two out of four occasions. The extent of stimulation of bulk bacterial heterotrophic production by single Fe or C additions increased with increasing in situ bacterial Fe uptake rates in the surface mixed layer. Our results provide evidence that both Fe and C are present at limiting concentrations for bacterial heterotrophic activity, in HNLC and fertilized regions, in spring. The observation that the extent of stimulation by both elements was related to Fe-uptake rates highlights the tight interaction between the C- and Fe-cycles through bacterial heterotrophic metabolism in the Southern Ocean.

scholarly journals Carbon fluxes through bacterial communities on glacier surfaces

2010 ◽  
Vol 51 (56) ◽  
pp. 32-40 ◽  
Author(s):  
Alexandre M. Anesio ◽  
Birgit Sattler ◽  
Christine Foreman ◽  
Jon Telling ◽  
Andy Hodson ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Bacterial Abundance ◽  
Heterotrophic Bacteria ◽  
Community Respiration ◽  
Organic C ◽  
C Cycle ◽  
Cryoconite Hole ◽  
Eukaryotic Organisms ◽  
Doubling Times

AbstractThere is very little information about the activity of microbial communities on the surface of glaciers, though there is an increasing body of evidence to show that they strongly influence the biogeochemistry of these habitats. We measured bacterial abundance and production in cryoconite holes on Arctic, Antarctic and Alpine glaciers in order to estimate the role of heterotrophic bacteria within the carbon budget of glacial ecosystems. Our results demonstrate an active bacterial community on the surface of glaciers with doubling times that vary from a few hours to hundreds of days depending on the glacier and position (water or sediments) within the cryoconite hole. However, bacterial production is only ∼2–3% of the published literature values of community respiration from similar habitats, indicating that other types of microbes (e.g. eukaryotic organisms) may also play a role in the C cycle of glaciers. We estimate that only up to 7% of the organic C in cryoconite sediments is utilized by the heterotrophic bacterial community annually, suggesting that the surface of glaciers can accumulate organic carbon, and that this C may be important for biogeochemical activity downstream to adjacent ecosystems.

Significance and fate of bacterial production in oligotrophic lakes in British Columbia

2000 ◽  
Vol 57 (1) ◽  
pp. 96-105 ◽  
Author(s):  
Thomas Weisse ◽  
Erland MacIsaac
Keyword(s):  
British Columbia ◽  
Bacterial Production ◽  
Bacterial Abundance ◽  
Trophic Levels ◽  
Lake Productivity ◽  
Relative Contribution ◽  
Carbon Biomass ◽  
Productivity Data ◽  
High Nutrient ◽  
Heterotrophic Nanoflagellate

We measured bacterial abundance, biomass, production rates, and grazing losses to protozoans in three oligotrophic British Columbia lakes and analyzed bacteria abundance and lake productivity data from 11 other lakes, most fertilized with inorganic nutrients to increase their productivity for juvenile salmon. Bacteria contributed about 24% to the phytoplankton-bacteria carbon biomass in the most ultraoligotrophic lakes, and their relative contribution declined to <11% with increasing lake productivity. At increasingly high nutrient loadings to the lakes, bacteria abundance increased and was closely correlated with phytoplankton biomass and productivity. Heterotrophic nanoflagellate (HNF) abundance was positively correlated with bacterial numbers. Grazing experiments revealed that HNF were the primary pathway for moving bacterial production to higher trophic levels in oligotrophic British Columbia lakes, and predation by the ciliate and rotifer microzooplankton community appeared to exert top-down control over the abundance of HNF and the transfer of carbon from bacteria. The HNF and microzooplankton, in turn, were affected by the abundance of crustacean mesozooplankton, principally copepods in our experiments.

scholarly journals Factors limiting heterotrophic bacterial production in the southern Pacific Ocean

2007 ◽  
Vol 4 (5) ◽  
pp. 3799-3828 ◽  
Author(s):  
F. Van Wambeke ◽  
S. Bonnet ◽  
T. Moutin ◽  
P. Raimbault ◽  
G. Alarçon ◽  
...  
Keyword(s):  
Bacterial Production ◽  
Heterotrophic Bacteria ◽  
Leucine Incorporation ◽  
Limiting Factor ◽  
Labile Carbon ◽  
Longitudinal Gradients ◽  
Eastern Border ◽  
Potential Factors ◽  
Seawater Samples

Abstract. The role of potential factors limiting bacterial growth was investigated along vertical and longitudinal gradients across the South Eastern Pacific Gyre. The effects of glucose, nitrate, ammonium and phosphate additions on heterotrophic bacterial production (using leucine technique) were studied in parallel in unfiltered seawater samples incubated under natural daily irradiance. Longitudinally, the enrichments realized on the subsurface showed three types of responses. From the Marquesas plateau (8° W to approx 125° W), bacteria were not bottom-up controlled, as confirmed by the huge potential of growth in non-enriched seawater (43±24 times in 24 h). Within the Gyre (125° W–95° W), nitrogen alone stimulated leucine incorporation rates by a factor of 5.6±3.6, but rapidly labile carbon (glucose) became a second limiting factor (enhancement factor 49±32 when the two elements were added). Finally from the border of the gyre to the Chilean upwelling (95° W–73° W), labile carbon was the only factor stimulating heterotrophic bacterial production. Interaction between phytoplankton and heterotrophic bacterial communities and the direct versus indirect effect of iron and macronutrients on bacterial production were also investigated in four selected sites: two sites on the vicinity of the Marquesas plateau, the centre of the gyre and the Eastern border of the gyre. Both phytoplankton and heterotrophic bacteria were limited by availability of nitrogen within the gyre, but not by iron. While iron limited phytoplankton at Marquesas plateau and at the eastern border of the gyre, heterotrophic bacteria were only limited by availability of labile DOC in those environments.

Estimation of bacterial production in fresh waters by the simultaneous measurement of [35S]Sulphate and D-[3H]glucose uptake in the dark

1978 ◽  
Vol 24 (8) ◽  
pp. 939-946 ◽  
Author(s):  
P. G. C. Campbell ◽  
J. H. Baker
Keyword(s):  
Bacterial Production ◽  
Membrane Filter ◽  
Outer Edge ◽  
Size Fractionation ◽  
Sulphate Uptake ◽  
Uptake Rates ◽  
Chalk Stream ◽  
Glucose Assimilation ◽  
Heterotrophic Production

Sulphate uptake in the dark by phytoplankton constitutes a severe limitation to the determination of bacterial heterotrophic production from sulphate-uptake rates. Consequently a modification to the 35S-method has been developed involving size fractionation to separate the algae from the bacteria. Both the whole water sample and the algae-free filtrate are incubated in the dark with trace quantities of [3H]glucose, whereas the filtrate alone is incubated with 35SO4. The experimental determined ratio (whole sample glucose assimilation: filtrate glucose assimilation) is used to correct the measured sulphate uptake (filtrate) and yields an estimate of bacterial sulphate uptake in the whole sample.A potential filtration artefact has been demonstrated in the 35SO4 uptake methodology. Excision of the outer edge of the membrane filter and counting of the inner wetted circle alone eliminated this problem and significantly improved the analytical performance of the method: coefficient of variation ~ 5%, detection limit ~ 2 ng S ℓ−1 h−1. The modified [35SO4]–[3H]-glucose method was applied to samples from an English chalk stream: bacterial sulphate uptake was higher during the spring diatom maximum (10.6 ng S ℓ−1 h−1) than 3 weeks later when detritus dominated the seston (4.9 ng S ℓ−1 h−1). We estimate the corresponding rates of formation of particulate (bacterial) carbon to be 0.53 and 0.24 μg C ℓ−1 h−1 respectively.

Elucidating the Role of Nitrifiers versus Heterotrophic bacteria in the Biotransformation of Pharmaceuticals during Wastewater Treatment

2008 ◽  
Vol 2008 (13) ◽  
pp. 3496-3504
Author(s):  
W. O. Khunjar ◽  
N. G. Love ◽  
J. Skotnicka-Pitak ◽  
D. Aga ◽  
W. F. Harper
Keyword(s):  
Wastewater Treatment ◽  
Heterotrophic Bacteria

scholarly journals Differing Growth Responses of Major Phylogenetic Groups of Marine Bacteria to Natural Phytoplankton Blooms in the Western North Pacific Ocean

2011 ◽  
Vol 77 (12) ◽  
pp. 4055-4065 ◽  
Author(s):  
Yuya Tada ◽  
Akito Taniguchi ◽  
Ippei Nagao ◽  
Takeshi Miki ◽  
Mitsuo Uematsu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Bacterial Community ◽  
North Pacific ◽  
Bacterial Production ◽  
Western North Pacific ◽  
Bacterial Abundance ◽  
North Pacific Ocean ◽  
Growth Potential ◽  
Phytoplankton Blooms ◽  
Content Type

ABSTRACTGrowth and productivity of phytoplankton substantially change organic matter characteristics, which affect bacterial abundance, productivity, and community structure in aquatic ecosystems. We analyzed bacterial community structures and measured activities inside and outside phytoplankton blooms in the western North Pacific Ocean by using bromodeoxyuridine immunocytochemistry and fluorescencein situhybridization (BIC-FISH).Roseobacter/Rhodobacter, SAR11,Betaproteobacteria,Alteromonas, SAR86, andBacteroidetesresponded differently to changes in organic matter supply.Roseobacter/Rhodobacterbacteria remained widespread, active, and proliferating despite large fluctuations in organic matter and chlorophylla(Chl-a) concentrations. The relative contribution ofBacteroidetesto total bacterial production was consistently high. Furthermore, we documented the unexpectedly large contribution ofAlteromonasto total bacterial production in the bloom. Bacterial abundance, productivity, and growth potential (the proportion of growing cells in a population) were significantly correlated with Chl-aand particulate organic carbon concentrations. Canonical correspondence analysis showed that organic matter supply was critical for determining bacterial community structures. The growth potential of each bacterial group as a function of Chl-aconcentration showed a bell-shaped distribution, indicating an optimal organic matter concentration to promote growth. The growth ofAlteromonasandBetaproteobacteriawas especially strongly correlated with organic matter supply. These data elucidate the distinctive ecological role of major bacterial taxa in organic matter cycling during open ocean phytoplankton blooms.

scholarly journals PENGARUH KERAPATAN LAMUN Thalassia hemprichii TERHADAP KELIMPAHAN BAKTERI HETEROTROF DI PANTAI PRAWEAN, JEPARA

2018 ◽  
Vol 7 (4) ◽  
pp. 415-422
Author(s):  
Isnaini Dian Yunita ◽  
Niniek Widyorini ◽  
Supriharyono Supriharyono
Keyword(s):  
Heterotrophic Bacteria ◽  
Nutrient Cycle ◽  
Thalassia Hemprichii ◽  
Enhalus Acoroides ◽  
Seagrass Ecosystem ◽  
Halodule Uninervis ◽  
Cymodocea Rotundata ◽  
Economic Function ◽  
Seagrass Density

Ekosistem lamun merupakan salah satu ekosistem yang memiliki kompleksitas dan keanekaragaman hayati yang tinggi. Padang lamun merupakan hamparan vegetasi lamun yang menutupi suatu kawasan pesisir. Selain memiliki fungsi ekonomi, lamun juga memiliki fungsi ekologis yakni berperan penting sebagai pendaur zat hara oleh mikroorganime yaitu bakteri. Penelitian ini bertujuan untuk mengetahui kerapatan lamun, kelimpahan bakteri heterotrof yang berasosiasi dengan lamun serta pengaruh kerapatan lamun dengan kelimpahan bakteri heterotrof di Pantai Prawean, Jepara. Metode yang digunakan yakni deskriptif eksplanatif dengan pengambilan sampel secara purposive dan dianalisis dengan IBM SPSS Statistic 22. Jenis lamun yang ditemukan di Pantai Prawean ada 5 (lima): Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Halodule uninervis dan Halodule pinifolia. Kerapatan tertinggi didapat dari jenis Thalassia hemprichii sebesar 78 Ind/m2 dan terendah adalah Enhalus acoroides 10 Ind/m2 dan kelimpahan bakteri heterotrof tertinggi diperoleh dari tingkat kerapatan rapat di stasiun 3 yakni 29,4x108 Upk/ml dan kelimpahan terendah diperoleh dari tingkat kerapatan jarang di stasiun 2 yakni 3,3x108 Upk/ml. Korelasi antara kerapatan lamun dengan kelimpahan bakteri heterotrof tinggi atau kuat yakni 0,896 dan korelasi ini dinyatakan sangat signifikan terbukti nilai sig. 0,001 dengan tingkat kesalahan 0,1%. Artinya bertambahnya kerapatan lamun dapat meningkatkan pula kelimpahan bakteri heterotrof. Seagrass ecosystem is one ecosytems that has high complexity and biodiversity. Seagrass beds are a stretch of seagrass vegetation that covers a coastal area. Beside its economic function, seagrass also have ecological function that play an important role of nutrient cycle for microorganism its bacteria. This study aims to determine the density of seagrass, the abundance of heterothropic bacteria and influence of seagrass density with abundance of heterotrophic bacteria at Prawean beach, Jepara. The method used in this study is descriptive explanative with purposive sampling and the data analyzed by IBM SPSS Statistic 22. There are 5 (five) species of seagrass that can be found in Prawean beach: Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Halodule uninervis and Halodule pinifolia. The highest density obtained from Thalassia hemprichii species is 78 sprouts of seagrass/m2 and the lowest density obtained from Enhalus acoroides is 10 obtained from seagrass density at station 3 its value 29,4x108Cfu/ml and the lowest abundance of heterotrophic bacteria was obtained from rare seagrass at station 2 its value 3,3x108Cfu/ml.  The corelation between seagrass density with abundance heterotrophic bacteria is high or strong that has value 0,846 and this correlation is very significantly proven has sig value 0,001 with error rate 0,1%, it can be conclude that increase of seagrass density can also increase the abundance of heterotrophic bacteria.  

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