scholarly journals UNICELLULAR PLANKTON TRANSFORMATION IN THE RIVER-BAY-RESERVOIR SYSTEM IN THE INITIAL PHASE OF CYANOBACTERIAL BLOOM

2021 ◽  
Vol 23 (5) ◽  
pp. 144-151
Author(s):  
M.V. Umanskaya ◽  
◽  
S.V. Bykova ◽  
M.Yu. Gorbunov ◽  
E.S. Krasnova ◽  
...  
Keyword(s):  
Structural Transformation ◽  
Initial Phase ◽  
Heterotrophic Bacteria ◽  
Initial Period ◽  
Cyanobacterial Bloom ◽  
Kuibyshev Reservoir ◽  
Adjacent Section ◽  
Reservoir System ◽  
Plankton Biomass ◽  
Quantitative Characteristics

The structure and spatial distributionof unicellular plankton of the river Usa, Usinsky Bay and the adjacent section of the Kuibyshev reservoir in the initial period of cyanobacterial bloom is discussed. The greatest development of plankton was recorded in the central part of Usinsky Bay. In the river part, the basis of the total plankton biomass was formed by heterotrophic bacteria and diatoms, and in the bay and reservoir –by cyanobacteria, mainly of the genera Aphanizomenon and Anabaena. Among eukaryotes in Usinskiy Bay, chlorophytesand diatoms prevailed, and in the reservoir - diatoms and ciliates. Another feature of plankton in the bay and reservoir was the increased proportion of heterotrophic bacteria and ciliates associated with cyanobacteria. The analysis of the structural transformation of communities made it possible to distinguish two main clusters of communities, "lotic" and "letic", which differ in their structure and quantitative characteristics.

scholarly journals Response of heterotrophic and autotrophic microbial plankton to inorganic and organic inputs along a latitudinal transect in the Atlantic Ocean

2010 ◽  
Vol 7 (5) ◽  
pp. 1701-1713 ◽  
Author(s):  
S. Martínez-García ◽  
E. Fernández ◽  
A. Calvo-Díaz ◽  
E. Marañón ◽  
X. A. G. Morán ◽  
...  
Keyword(s):  
Organic Matter ◽  
Atlantic Ocean ◽  
Bacterial Growth ◽  
Heterotrophic Bacteria ◽  
Growth Efficiency ◽  
Bacterial Growth Efficiency ◽  
Organic Nutrient ◽  
Plankton Biomass ◽  
Latitudinal Transect ◽  
Microbial Plankton

Abstract. The effects of inorganic and/or organic nutrient inputs on phytoplankton and heterotrophic bacteria have never been concurrently assessed in open ocean oligotrophic communities over a wide spatial gradient. We studied the effects of potentially limiting inorganic (nitrate, ammonium, phosphate, silica) and organic nutrient (glucose, aminoacids) inputs added separately as well as jointly, on microbial plankton biomass, community structure and metabolism in five microcosm experiments conducted along a latitudinal transect in the Atlantic Ocean (from 26° N to 29° S). Primary production rates increased up to 1.8-fold. Bacterial respiration and microbial community respiration increased up to 14.3 and 12.7-fold respectively. Bacterial production and bacterial growth efficiency increased up to 58.8-fold and 2.5-fold respectively. The largest increases were measured after mixed inorganic-organic nutrients additions. Changes in microbial plankton biomass were small as compared with those in metabolic rates. A north to south increase in the response of heterotrophic bacteria was observed, which could be related to a latitudinal gradient in phosphorus availability. Our results suggest that organic matter inputs will result in a predominantly heterotrophic versus autotrophic response and in increases in bacterial growth efficiency, particularly in the southern hemisphere. Subtle differences in the initial environmental and biological conditions are likely to result in differential microbial responses to inorganic and organic matter inputs.

scholarly journals FREE-LIVING CILIATES DURING THE PERIOD OF THE GREATEST CYANOBACTERIAL WATER BLOOM IN THE USINSKY BAY (KUIBYSHEV RESERVOIR)

2021 ◽  
Vol 23 (5) ◽  
pp. 127-134
Author(s):  
V.A. Andreeva ◽  
◽  
S.V. Bykova ◽  
M.V. Umanskaya ◽  
N.G. Tarasova ◽  
...  
Keyword(s):  
Single Cells ◽  
Cyanobacterial Bloom ◽  
Water Bloom ◽  
Species Structure ◽  
Kuibyshev Reservoir ◽  
Free Living ◽  
Ciliate Community ◽  
Ciliate Species ◽  
Bloom Water

The study of free-living ciliates in the Usinsky bay (the Kuibyshev reservoir) during the period of mass development of cyanobacteria are presented. The diversity of the ciliate species structure and spatial distribution were studied in summer. The abundance of ciliates varied from 124 to 1176 103ind./m3, biomass – from 6.9 mg/m3 to 104.9 mg/m3 during the study period. No significant differences in the communities of ciliates in different ecotopes of the bay (riverbed, open and overgrown by macrophytes coastal areas) were found. However, on average, in the riverbed part, all indicators of species richness and diversity, and quantitative developmentwere higher than in the littoral zone. The massive development of representatives of s/cl. Peritrichia (up to 51% of abundance and 66% of biomass): single cells species associated with planktonic algae (genera Vorticella, Vaginicola), and colonial free-floating Epistylisprocumbens Zacharias, 1897, was the distinctive feature of ciliate community in the UsinskyBay during the period of greatest cyanobacterial bloom. Water bloom significantly changed the trophic structure of the ciliate community: the role of algophages and nonselective omnivores, ordinary trophic groups of the Reservoir was significantly reduced, and bacterio-detritophages became absolutely dominated. It was shown that the dominant species of cyanobacteria had a significant effect on the ciliate community during the cyanobacterial water bloom.

scholarly journals Microcystin Biosynthesis andmcyAExpression in Geographically DistinctMicrocystisStrains under Different Nitrogen, Phosphorus, and Boron Regimes

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Ankita Srivastava ◽  
So-Ra Ko ◽  
Chi-Yong Ahn ◽  
Hee-Mock Oh ◽  
Alok Kumar Ravi ◽  
...  
Keyword(s):  
South Korea ◽  
Environmental Variables ◽  
Reference Strain ◽  
Heterotrophic Bacteria ◽  
Cyanobacterial Bloom ◽  
Photoautotrophic Growth ◽  
Microcystin Concentration ◽  
Alpha Beta ◽  
Nitrogen Phosphorus

Roles of nutrients and other environmental variables in development of cyanobacterial bloom and its toxicity are complex and not well understood. We have monitored the photoautotrophic growth, total microcystin concentration, and microcystins synthetase gene (mcyA) expression in lab-grown strains ofMicrocystisNIES 843 (reference strain), KW (Wangsong Reservoir, South Korea), and Durgakund (Varanasi, India) under different nutrient regimes (nitrogen, phosphorus, and boron). Higher level of nitrogen and boron resulted in increased growth (avg. 5 and 6.5 Chlamg/L, resp.), total microcystin concentrations (avg. 1.185 and 7.153 mg/L, resp.), andmcyAtranscript but its expression was not directly correlated with total microcystin concentrations in the target strains. Interestingly, Durgakund strain had much lower microcystin content and lacked microcystin-YR variant over NIES 843 and KW. It is inferred that microcystin concentration and its variants are strain specific. We have also examined the heterotrophic bacteria associated with cyanobacterial bloom in Durgakund Pond and Wangsong Reservoir which were found to be enriched in Alpha-, Beta-, and Gammaproteobacteria and that could influence the bloom dynamics.

scholarly journals Influence of cyclonic and anti-cyclonic eddies on plankton biomass, activity and diversity in the southeastern Mediterranean Sea

2022 ◽  
Author(s):  
Natalia Belkin ◽  
Tamar Guy-Haim ◽  
Maxim Rubin-Blum ◽  
Ayah Lazar ◽  
Guy Sisma-Ventura ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Doubling Time ◽  
Heterotrophic Bacteria ◽  
Specific Activity ◽  
Late Summer ◽  
Zooplankton Biomass ◽  
Planktonic Food ◽  
C Cell ◽  
Plankton Biomass ◽  
Biomass Activity

Abstract. Planktonic food-webs were studied contemporaneously in a mesoscale cyclonic (upwelling, ~13 months old) and an anti-cyclonic (down-welling, ~2 months old) eddies, as well as in an uninfluenced-background situation in the oligotrophic southeastern Mediterranean Sea (SEMS) during late summer 2018. We show that integrated nutrients concentrations were higher at the cyclone compared to the anti-cyclone or the background stations by 2–13 fold. Concurrently, Synechococcus and Prochlorococcus were the dominant community component abundance-wise in the oligotrophic anti-cyclone (~300 × 1010 cells m−2). In the cyclone, pico- and nanoeukaryotes such as dinoflagellates, Prymnesiophyceae and Ochrophyta contributed substantially to the total phytoplankton abundnce (~14 × 1010 cells m−2) which was ~65 % lower in the anti-cyclone/background stations (~5 × 1010 cells m−2). Primary production was highest in the cyclonic eddy (191 mg C m−2 d−1) and was 2–5 fold lower outside the eddy area. The calculated doubling time of phytoplankton was ~3 days in the cyclone and ~5–10 days at the anti-cyclone/background stations, further reflecting the nutritional differences between these environments. Heterotrophic prokaryotic cell-specific activity was highest in the cyclone (~10 fg C cell−1 d−1), while the least productive cells were found in the anti-cyclone (4 fg C cell−1 d−1). The calculated doubling time of heterotrophic bacteria were 1.4 days in the cyclone and 2.5–3.5 days at the anti-cyclone/background stations. Total zooplankton biomass in the upper 300 m was tenfold higher in the cyclone compared with the anti-cyclone or background stations (1337 vs. 112–133 mg C m−2, respectively). Copepod diversity was much higher in the cyclone (44 species), compared to the anti-cyclone (6 small-size species). Our results highlight that cyclonic and anti-cyclonic eddies show significantly different community compositions and food-web dynamics in oligotrophic environments, with cyclones representing productive oases in the marine desert of the SEMS.

scholarly journals Transfer of diazotroph derived nitrogen towards non-diazotrophic planktonic communities: a comparative study between <i>Trichodesmium</i> <i>erythraeum</i>, <i>Crocosphaera watsonii</i> and <i>Cyanothece</i> sp.

2016 ◽  
Author(s):  
H. Berthelot ◽  
S. Bonnet ◽  
O. Grosso ◽  
V. Cornet ◽  
A. Barani
Keyword(s):  
N2 Fixation ◽  
Secondary Ion Mass Spectrometry ◽  
Heterotrophic Bacteria ◽  
New Caledonia ◽  
Transfer Efficiency ◽  
Ecological Niches ◽  
Plankton Biomass ◽  
Marine Productivity ◽  
Oligotrophic Ecosystem ◽  
Crocosphaera Watsonii

Abstract. Biological dinitrogen (N2) fixation is the major source of new nitrogen (N) for the open ocean, and thus promotes marine productivity, in particular in the vast N-depleted regions of the surface ocean. Yet, the fate of the diazotroph-derived N (DDN) in marine ecosystems is poorly understood and its transfer to auto- and heterotrophic surrounding plankton communities is rarely measured due to technical limitations. Moreover, the different diazotrophs involved in N2 fixation (Trichodesmium spp. vs. UCYN) exhibit distinct patterns of N2 fixation and inhabit different ecological niches, thus having potentially different fates in the marine food webs, that remains to be explored. Here we used nanometer scale secondary ion mass spectrometry (nanoSIMS) coupled with 15N2 isotopic labelling and flow cytometry cell sorting to examine the DDN transfer to specific groups of natural phytoplankton and bacteria during artificially-induced diazotroph blooms in New Caledonia (southwestern Pacific). The fate of the DDN was compared according to the three diazotrophs: the filamentous and colony forming Trichodesmium erythraeum (IMS101), and the unicellular strains Crocosphaera watsonii WH8501 and Cyanothece ATCC51142. After 48 h, 7–17 % of the N2 fixed during the experiment was transferred to the dissolved pool and 6–12 % was transferred to non-diazotrophic plankton. The transfer was twice as high during the T. erythraeum bloom than during the C. watsonii and Cyanothece blooms, arguing that filamentous diazotrophs blooms are more efficient at promoting non-diazotrophic production in N depleted areas. The amount of DDN released in the dissolved pool did not appear as a good indicator of the DDN transfer efficiency towards the non-diazotrophic plankton. In contrast, the 15N-enrichment of the extracellular ammonium (NH4+) pool was a good indicator of the DDN transfer efficiency: it was significantly higher in the T. erythraeum than in unicellular diazotroph blooms, leading to a DDN transfer twice as efficient. This suggests that NH4+ was the main pathway of the DDN transfer from diazotrophs to non-diazotrophs. The three simulated diazotroph blooms led to significant increases in non-diazotrophic plankton biomass. This increase in biomass was first associated with heterotrophic bacteria followed phytoplankton, indicating that heterotrophs took the most advantage of the DDN in this oligotrophic ecosystem.

scholarly journals Transfer of diazotroph-derived nitrogen towards non-diazotrophic planktonic communities: a comparative study between <i>Trichodesmium</i> <i>erythraeum</i>, <i>Crocosphaera watsonii</i> and <i>Cyanothece</i> sp.

2016 ◽  
Vol 13 (13) ◽  
pp. 4005-4021 ◽  
Author(s):  
Hugo Berthelot ◽  
Sophie Bonnet ◽  
Olivier Grosso ◽  
Véronique Cornet ◽  
Aude Barani
Keyword(s):  
N2 Fixation ◽  
Secondary Ion Mass Spectrometry ◽  
Heterotrophic Bacteria ◽  
New Caledonia ◽  
Transfer Efficiency ◽  
Ecological Niches ◽  
Plankton Biomass ◽  
Marine Productivity ◽  
Oligotrophic Ecosystem ◽  
Crocosphaera Watsonii

Abstract. Biological dinitrogen (N2) fixation is the major source of new nitrogen (N) for the open ocean, and thus promotes marine productivity, in particular in the vast N-depleted regions of the surface ocean. Yet, the fate of the diazotroph-derived N (DDN) in marine ecosystems is poorly understood, and its transfer to auto- and heterotrophic surrounding plankton communities is rarely measured due to technical limitations. Moreover, the different diazotrophs involved in N2 fixation (Trichodesmium spp. vs. UCYN) exhibit distinct patterns of N2 fixation and inhabit different ecological niches, thus having potentially different fates in the marine food webs that remain to be explored. Here we used nanometer scale secondary ion mass spectrometry (nanoSIMS) coupled with 15N2 isotopic labelling and flow cytometry cell sorting to examine the DDN transfer to specific groups of natural phytoplankton and bacteria during artificially induced diazotroph blooms in New Caledonia (southwestern Pacific). The fate of the DDN was compared according to the three diazotrophs: the filamentous and colony-forming Trichodesmium erythraeum (IMS101), and the unicellular strains Crocosphaera watsonii WH8501 and Cyanothece ATCC51142. After 48 h, 7–17 % of the N2 fixed during the experiment was transferred to the dissolved pool and 6–12 % was transferred to non-diazotrophic plankton. The transfer was twice as high in the T. erythraeum bloom than in the C. watsonii and Cyanothece blooms, which shows that filamentous diazotrophs blooms are more efficient at promoting non-diazotrophic production in N-depleted areas. The amount of DDN released in the dissolved pool did not appear to be a good indicator of the DDN transfer efficiency towards the non-diazotrophic plankton. In contrast, the 15N-enrichment of the extracellular ammonium (NH4+) pool was a good indicator of the DDN transfer efficiency: it was significantly higher in the T. erythraeum than in unicellular diazotroph blooms, leading to a DDN transfer twice as efficient. This suggests that NH4+ was the main pathway of the DDN transfer from diazotrophs to non-diazotrophs. The three simulated diazotroph blooms led to significant increases in non-diazotrophic plankton biomass. This increase in biomass was first associated with heterotrophic bacteria followed by phytoplankton, indicating that heterotrophs took the most advantage of the DDN in this oligotrophic ecosystem.

scholarly journals Response of heterotrophic and autotrophic microbial plankton to inorganic and organic inputs along a latitudinal transect in the Atlantic Ocean

2010 ◽  
Vol 7 (1) ◽  
pp. 463-502
Author(s):  
S. Martínez-García ◽  
E. Fernández ◽  
A. Calvo-Díaz ◽  
E. Marañón ◽  
X. A. G. Morán ◽  
...  
Keyword(s):  
Organic Matter ◽  
Atlantic Ocean ◽  
Bacterial Growth ◽  
Heterotrophic Bacteria ◽  
Growth Efficiency ◽  
Bacterial Growth Efficiency ◽  
Organic Nutrient ◽  
Plankton Biomass ◽  
Latitudinal Transect ◽  
Microbial Plankton

Abstract. Atmospheric nutrient deposition into the open ocean increased over the past decades as a result of human activity and water-soluble organic nitrogen accounts for up to 30% of the total nitrogen inputs. The effects of inorganic and/or organic nutrient inputs on phytoplankton and heterotrophic bacteria have never been concurrently assessed in open ocean oligotrophic communities over a wide spatial gradient. We studied the effects of potentially limiting inorganic (nitrate, ammonium, phosphate, silica) and organic nutrient (glucose, aminoacids) inputs on microbial plankton biomass, community structure and metabolism in five microcosm experiments conducted along a latitudinal transect in the Atlantic Ocean (from 26° N to 29° S). Primary production rates increased up to 1.8-fold. Bacterial respiration and microbial community respiration increased up to 14.3 and 12.7-fold, respectively. Bacterial production and bacterial growth efficiency increased up to 58.8-fold and 2.5-fold, respectively. The largest increases were measured after mixed inorganic-organic nutrients additions. Changes in microbial plankton biomass were small as compared with those in metabolic rates. A north to south increase in the response of heterotrophic bacteria was observed, which could be related to a latitudinal gradient in phosphorus availability. Our results suggest that organic matter inputs associated with atmospheric deposition into the Atlantic Ocean will result in a predominantly heterotrophic versus autotrophic response and in increases in bacterial growth efficiency, particularly in the Southern Hemisphere. Subtle differences in the initial environmental and biological conditions are likely to result in differential microbial responses to inorganic and organic matter inputs.

scholarly journals Distinctive tasks of different cyanobacteria and associated bacteria in carbon as well as nitrogen fixation and cycling in a late stage Baltic Sea bloom

2019 ◽  
Author(s):  
Falk Eigemann ◽  
Angela Vogts ◽  
Maren Voss ◽  
Luca Zoccarato ◽  
Heide Schulz-Vogt
Keyword(s):  
Nitrogen Fixation ◽  
Baltic Sea ◽  
Late Stage ◽  
Carbon Fixation ◽  
Heterotrophic Bacteria ◽  
Cyanobacterial Bloom ◽  
Cyanobacterial Blooms ◽  
Carbon And Nitrogen ◽  
Cyanobacterial Species ◽  
Uptake Rates

AbstractCyanobacteria and associated heterotrophic bacteria hold key roles in carbon as well as nitrogen fixation and cycling in the Baltic Sea due to massive cyanobacterial blooms each summer. The species specific activities of different cyanobacterial species as well as the N- and C-exchange of associated heterotrophic bacteria in these processes, however, are widely unknown. Within one time series experiment we tested the cycling in a natural, late stage cyanobacterial bloom by adding 13C bi-carbonate and 15N2, and performed sampling after 10 min, 30 min, 1 h, 6 h and 24 h in order to determine the fixing species as well as the fate of the fixed carbon and nitrogen in the associations. Uptake of 15N and 13C isotopes by the most abundant cyanobacterial species as well as the most abundant associated heterotrophic bacterial groups was then analysed with a NanoSIMS. Overall, the filamentous, heterocystous species Dolichospermum sp., Nodularia sp., and Aphanizomenon sp. revealed no or erratic uptake of carbon and nitrogen, indicating mostly inactive cells. In contrary, non-heterocystous Pseudanabaena sp. dominated the nitrogen and carbon fixation, with uptake rates up to 1.49 ± 0.47 nmol N h-1 l-1 and 2.55 ± 0.91 nmol C h-1 l-1. Associated heterotrophic bacteria dominated the subsequent nitrogen cycling with uptake rates up to 1.2 ± 1.93 fmol N h-1 cell -1, but were also indicative for fixation of di-nitrogen.

scholarly journals Initial and long-term antithrombotic therapy after left atrial appendage closure with the WATCHMAN

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Ledwoch ◽  
K Sievert ◽  
L Boersma ◽  
M Bergmann ◽  
H Ince ◽  
...  
Keyword(s):  
Antiplatelet Therapy ◽  
Left Atrial ◽  
Initial Phase ◽  
Left Atrial Appendage ◽  
Initial Period ◽  
Atrial Appendage ◽  
Funding Source ◽  
Second Period ◽  
Laa Closure

Abstract Background Evidence regarding post-procedural antithrombotic regimes other than used in randomized trials assessing percutaneous left atrial appendage (LAA) closure is limited. Purpose The present work aimed to compare different antithrombotic strategies applied in the real-world EWOLUTION study. Methods A total of 998 patients with successful WATCHMAN implantation at 47 centers were available for the present analysis. The composite ischemic endpoint of stroke, TIA, systemic embolism and device thrombus as well as the bleeding endpoint defined as at least major bleeding according to BARC were assessed during an initial period (from implant until first medication change) and long-term period (from first change until up to 2 years). Results The antithrombotic medication chosen in the initial phase was dual antiplatelet therapy (DAPT) in 60%, oral anticoagulation (OAC) in 27%, single antiplatelet therapy (SAPT) in 7% and no medication in 6%. In the long-term phase SAPT was used in 65%, DAPT in 23%, no therapy in 8% and OAC in 4%. No significant differences were found between the groups regarding the ischemic endpoint both in the initial period (Kaplan-Meier estimated rate 2.9% for DAPT vs. 4.3% for OAC vs. 3.9% for SAPT or no therapy; p=0.97) and in the second period (4.2% for SAPT vs. 1.8% for DAPT vs. 3.5% for no therapy; p=0.36). With respect to bleeding events the only difference was found in the initial phase with a higher incidence in patients under SAPT or no therapy (1.0% for DAPT vs. 0.8% for OAC vs. 7.4% for SAPT or no therapy; p=0.01). No differences in bleeding complications were observed during the second period (2.6% for SAPT vs. 2.9% for DAPT vs. 2.2% for no therapy; p=0.88). Conclusions Tailored antithrombotic treatment using even very reduced strategies such as SAPT or no therapy showed no significant differences regarding ischemic complications after LAA closure. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Boston Scientific

scholarly journals Influence of Cyanobacterial Bloom on Freshwater Biocoenosis. Use of Bioassays for Cyanobacterial Microcystins Toxicity Assessment

2017 ◽  
Vol 24 (1) ◽  
pp. 47-68 ◽  
Author(s):  
Marlena Piontek ◽  
Wanda Czyżewska
Keyword(s):  
Escherichia Coli ◽  
Daphnia Magna ◽  
Enterococcus Faecalis ◽  
Aquatic Invertebrates ◽  
Methanol Extract ◽  
Heterotrophic Bacteria ◽  
Cyanobacterial Bloom ◽  
Toxicity Assessment ◽  
Cyanobacterial Blooms ◽  
Dugesia Tigrina

Abstract The issues presented in this study concern a very important problem of the occurrence of cyanobacterial blooms in surface water used for water supply purposes. The objective of this study was to analyze the occurrence of cyanotoxic risk in the catchment area of the Obrzyca River (including Sławskie lake which is the beginning of the river), which is a source of drinking water for the inhabitants of Zielona Góra. In order to evaluate toxicity of cyanobacterial bloom it was conducted toxicological testing using aquatic invertebrates (Daphnia magna, Dugesia tigrina) and heterotrophic bacteria (Escherichia coli, Enterococcus faecalis, Pseudomonas fluorescens). Test samples were collected from May to October, 2012. The most toxic was a sample collected from Lake Sławskie on 20th October when cyanobacteria bloom with a predominance of Microcystis aeruginosa occurred and the amount of microcystins was the largest. The methanol extract of the sample was toxic only above a concentration of 6·103 mg·dm-3. The lethal concentration (48-h LC 50) for Daphnia magna was 3.09·103 and for Dugesia tigrina (240-h LC 50) 1.51·103 mg·dm-3 of microcystins (MC-LR, MC-YR and MC-RR). The same extract stimulated growth of Escherichia coli and Enterococcus faecalis cells.

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