scholarly journals Competition for inorganic and organic forms of nitrogen and phosphorous between phytoplankton and bacteria during an <I>Emiliania huxleyi</I> spring bloom (PeECE II)

2007 ◽  
Vol 4 (5) ◽  
pp. 3343-3375 ◽  
Author(s):  
T. Løvdal ◽  
C. Eichner ◽  
H.-P. Grossart ◽  
V. Carbonnel ◽  
L. Chou ◽  
...  
Keyword(s):  
Large Particle ◽  
Spring Bloom ◽  
Heterotrophic Bacteria ◽  
Phytoplankton Bloom ◽  
Inorganic Nitrogen ◽  
Size Fraction ◽  
Emiliania Huxleyi ◽  
Associated Bacteria ◽  
Specific Affinity ◽  
Microbial Food Chain

Abstract. Using 15N and 33P, we measured the turnover of organic and inorganic nitrogen (N) and phosphorus (P) substrates, and the partitioning of N and P from these sources into two size fractions of marine osmotrophs during the course of a phytoplankton bloom in a nutrient manipulated mesocosm. The larger size fraction (>0.8 μm), mainly consisting of the coccolithophorid Emiliania huxleyi, but also including an increasing amount of large particle-associated bacteria as the bloom proceeded, dominated uptake of the inorganic forms NH4+, NO3−, and PO43−. The uptake of N from leucine, and P from ATP and dissolved DNA (dDNA), was initially dominated by the 0.8–0.2 μm size fraction, but shifted towards dominance by the >0.8 μm size fraction as the system turned to an increasing degree of N-deficiency. Normalizing uptake to biomass of phytoplankton and heterotrophic bacteria revealed that organisms in the 0.8–0.2 μm size fraction had higher specific affinity for leucine-N than those in the >0.8 μm size fraction when N was deficient, whereas the opposite was the case for NH4+. There was no such difference regarding the specific affinity for P substrates. Since heterotrophic bacteria seem to acquire N from organic compounds like leucine more efficiently than phytoplankton, our results suggest different structuring of the microbial food chain in N-limited relative to P-limited environments.

scholarly journals Competition for inorganic and organic forms of nitrogen and phosphorous between phytoplankton and bacteria during an <i>Emiliania huxleyi</i> spring bloom

2008 ◽  
Vol 5 (2) ◽  
pp. 371-383 ◽  
Author(s):  
T. Løvdal ◽  
C. Eichner ◽  
H.-P. Grossart ◽  
V. Carbonnel ◽  
L. Chou ◽  
...  
Keyword(s):  
Large Particle ◽  
Spring Bloom ◽  
Heterotrophic Bacteria ◽  
Phytoplankton Bloom ◽  
Inorganic Nitrogen ◽  
Size Fraction ◽  
Emiliania Huxleyi ◽  
Associated Bacteria ◽  
Specific Affinity ◽  
Microbial Food Chain

Abstract. Using 15N and 33P, we measured the turnover of organic and inorganic nitrogen (N) and phosphorus (P) substrates, and the partitioning of N and P from these sources into two size fractions of marine osmotrophs during the course of a phytoplankton bloom in a nutrient manipulated mesocosm. The larger size fraction (>0.8 μm), mainly consisting of the coccolithophorid Emiliania huxleyi, but also including an increasing amount of large particle-associated bacteria as the bloom proceeded, dominated uptake of the inorganic forms NH4+, NO3−, and PO43−. The uptake of N from leucine, and P from ATP and dissolved DNA, was initially dominated by the 0.8–0.2 μm size fraction, but shifted towards dominance by the >0.8 μm size fraction as the system turned to an increasing degree of N-deficiency. Normalizing uptake to biomass of phytoplankton and heterotrophic bacteria revealed that organisms in the 0.8–0.2 μm size fraction had higher specific affinity for leucine-N than those in the >0.8 μm size fraction when N was deficient, whereas the opposite was the case for NH4+. There was no such difference regarding the specific affinity for P substrates. Since heterotrophic bacteria seem to acquire N from organic compounds like leucine more efficiently than phytoplankton, our results suggest different structuring of the microbial food chain in N-limited relative to P-limited environments.

Bacterioplankton, Phytoplankton, and Zooplankton Communities in a British Columbia Coastal Lake Before and After Nutrient Reduction

1986 ◽  
Vol 43 (8) ◽  
pp. 1504-1514 ◽  
Author(s):  
F. Joan Hardy ◽  
Ken S. Shortreed ◽  
John G. Stockner
Keyword(s):  
British Columbia ◽  
Sockeye Salmon ◽  
Inorganic Nitrogen ◽  
Size Fraction ◽  
Growing Season ◽  
Nutrient Reduction ◽  
Nitrogen And Phosphorus ◽  
Coastal Lake ◽  
Before And After ◽  
High Concentrations

Inorganic nitrogen and phosphorus were applied weekly during the growing season from 1980 to 1982 and twice weekly in 1983 to Hobiton Lake, a warm monomictic coastal lake in British Columbia. The lake was not fertilized in 1984. Average numbers of bacteria during the growing season decreased from a high of 1.53 × 106∙mL−1 in the fertilized condition to 0.84 × 106∙mL−1 in the unfertilized condition. Chlorophyll a concentrations decreased from a maximum seasonal average of 2.69 μg∙L−1 (1981) to 1.30 μg∙L−1 (1984), and algal numbers decreased from 5.83 × 104∙mL−1 (1983) to 2.29 × 104∙mL−1 (1984). Although the numbers of phytoplankton in each size fraction (picoplankton, nanoplankton, or microplankton) decreased in the unfertilized condition, the greatest change was an almost fourfold decrease in picoplankton, which consisted of 90% cyanobacteria (primarily Synechococcus spp.). Abundance of the large diatoms Rhizosolenia spp. and Melosira spp. increased in 1984, resulting in an increase in average seasonal algal volume. Average densities of medium (0.15–0.84 mm) and large (0.85–1.5 mm) zooplankton were greatest in 1982, while rotifers and small zooplankton (0.10–0.14 mm) were most dense in 1984 following nutrient reduction. The lake had relatively high concentrations of planktivorous juvenile sockeye salmon (Oncorhynchus nerka) that appeared to minimize any direct effect of nutrient additions on zooplankton densities.

scholarly journals Isolation of axenic cyanobacterium and the promoting effect of associated bacterium on axenic cyanobacterium

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Suqin Gao ◽  
Yun Kong ◽  
Jing Yu ◽  
Lihong Miao ◽  
Lipeng Ji ◽  
...  
Keyword(s):  
Heterotrophic Bacteria ◽  
Specific Interaction ◽  
Cyanobacterial Blooms ◽  
Organic Substrates ◽  
Promoting Effect ◽  
Associated Bacteria ◽  
Purification Technique ◽  
Harmful Cyanobacterial Blooms ◽  
Solid Liquid ◽  
Water Quality Deterioration

Abstract Background Harmful cyanobacterial blooms have attracted wide attention all over the world as they cause water quality deterioration and ecosystem health issues. Microcystis aeruginosa associated with a large number of bacteria is one of the most common and widespread bloom-forming cyanobacteria that secret toxins. These associated bacteria are considered to benefit from organic substrates released by the cyanobacterium. In order to avoid the influence of associated heterotrophic bacteria on the target cyanobacteria for physiological and molecular studies, it is urgent to obtain an axenic M. aeruginosa culture and further investigate the specific interaction between the heterotroph and the cyanobacterium. Results A traditional and reliable method based on solid-liquid alternate cultivation was carried out to purify the xenic cyanobacterium M. aeruginosa FACHB-905. On the basis of 16S rDNA gene sequences, two associated bacteria named strain B905–1 and strain B905–2, were identified as Pannonibacter sp. and Chryseobacterium sp. with a 99 and 97% similarity value, respectively. The axenic M. aeruginosa FACHB-905A (Microcystis 905A) was not able to form colonies on BG11 agar medium without the addition of strain B905–1, while it grew well in BG11 liquid medium. Although the presence of B905–1 was not indispensable for the growth of Microcystis 905A, B905–1 had a positive effect on promoting the growth of Microcystis 905A. Conclusions The associated bacteria were eliminated by solid-liquid alternate cultivation method and the axenic Microcystis 905A was successfully purified. The associated bacterium B905–1 has the potentiality to promote the growth of Microcystis 905A. Moreover, the purification technique for cyanobacteria described in this study is potentially applicable to a wider range of unicellular cyanobacteria.

scholarly journals Use of Microautoradiography Combined with Fluorescence In Situ Hybridization To Determine Dimethylsulfoniopropionate Incorporation by Marine Bacterioplankton Taxa

2004 ◽  
Vol 70 (8) ◽  
pp. 4648-4657 ◽  
Author(s):  
Maria Vila ◽  
Rafel Simó ◽  
Ronald P. Kiene ◽  
Jarone Pinhassi ◽  
José M. González ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Gulf Of Mexico ◽  
Fluorescence In Situ Hybridization ◽  
Marine Bacteria ◽  
Heterotrophic Bacteria ◽  
Phytoplankton Bloom ◽  
Mediterranean Coast ◽  
Marine Bacterioplankton ◽  
Significant Uptake

ABSTRACT The fraction of planktonic heterotrophic bacteria capable of incorporating dissolved dimethylsulfoniopropionate (DMSP) and leucine was determined at two coastal sites by microautoradioagraphy (AU). In Gulf of Mexico seawater microcosm experiments, the proportion of prokaryotes that incorporated sulfur from [35S]DMSP ranged between 27 and 51% of 4′,6-diamidino-2-phenylindole (DAPI)-positive cells, similar to or slightly lower than the proportion incorporating [3H]leucine. In the northwest Mediterranean coast, the proportion of cells incorporating sulfur from [35S]DMSP increased from 5 to 42% from January to March, coinciding with the development of a phytoplankton bloom. At the same time, the proportion of cells incorporating [3H]leucine increased from 21 to 40%. The combination of AU and fluorescence in situ hybridization (FISH) revealed that the Roseobacter clade (α-proteobacteria) accounted for 13 to 43% of the microorganisms incorporating [35S]DMSP at both sampling sites. Significant uptake of sulfur from DMSP was also found among members of the γ-proteobacteria and Cytophaga-Flavobacterium groups. Roseobacter and γ-proteobacteria exhibited the highest percentage of DAPI-positive cells incorporating 35S from DMSP (around 50%). Altogether, the application of AU with [35S]DMSP combined with FISH indicated that utilization of S from DMSP is a widespread feature among active marine bacteria, comparable to leucine utilization. These results point toward DMSP as an important substrate for a broad and diverse fraction of marine bacterioplankton.

scholarly journals The importance of phytoplankton trait variability in spring bloom formation

2015 ◽  
Vol 72 (6) ◽  
pp. 1908-1915 ◽  
Author(s):  
Aleksandra M. Lewandowska ◽  
Maren Striebel ◽  
Ulrike Feudel ◽  
Helmut Hillebrand ◽  
Ulrich Sommer
Keyword(s):  
Spring Bloom ◽  
Phytoplankton Bloom ◽  
High Growth ◽  
Phytoplankton Blooms ◽  
Mixing Processes ◽  
Bloom Formation ◽  
Alternative Hypotheses ◽  
Phytoplankton Traits ◽  
Trait Variability

Abstract About 60 years ago, the critical depth hypothesis was proposed to describe the occurrence of spring phytoplankton blooms and emphasized the role of stratification for the timing of onset. Since then, several alternative hypotheses appeared focusing on the role of grazing and mixing processes such as turbulent convection or wind activity. Surprisingly, the role of community composition—and thus the distribution of phytoplankton traits—for bloom formation has not been addressed. Here, we discuss how trait variability between competing species might influence phytoplankton growth during the onset of the spring bloom. We hypothesize that the bloom will only occur if there are species with a combination of traits fitting to the environmental conditions at the respective location and time. The basic traits for formation of the typical spring bloom are high growth rates and photoadaptation to low light conditions, but other traits such as nutrient kinetics and grazing resistance might also be important. We present concise ideas on how to test our theoretical considerations experimentally. Furthermore, we suggest that future models of phytoplankton blooms should include both water column dynamics and variability of phytoplankton traits to make realistic projections instead of treating the phytoplankton bloom as an aggregate community phenomenon.

scholarly journals Single-colony sequencing reveals microbe-by-microbiome phylosymbiosis between the cyanobacterium Microcystis and its associated bacteria

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Olga M. Pérez-Carrascal ◽  
Nicolas Tromas ◽  
Yves Terrat ◽  
Elisa Moreno ◽  
Alessandra Giani ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Heterotrophic Bacteria ◽  
Bacterial Species ◽  
Colony Growth ◽  
Genomic Diversity ◽  
Gene Copy ◽  
Metagenomic Sequencing ◽  
Associated Bacteria ◽  
Microbiome Composition

Abstract Background Cyanobacteria from the genus Microcystis can form large mucilaginous colonies with attached heterotrophic bacteria—their microbiome. However, the nature of the relationship between Microcystis and its microbiome remains unclear. Is it a long-term, evolutionarily stable association? Which partners benefit? Here we report the genomic diversity of 109 individual Microcystis colonies—including cyanobacteria and associated bacterial genomes—isolated in situ and without culture from Lake Champlain, Canada and Pampulha Reservoir, Brazil. Results We identified 14 distinct Microcystis genotypes from Canada, of which only two have been previously reported, and four genotypes specific to Brazil. Microcystis genetic diversity was much greater between than within colonies, consistent with colony growth by clonal expansion rather than aggregation of Microcystis cells. We also identified 72 bacterial species in the microbiome. Each Microcystis genotype had a distinct microbiome composition, and more closely related genotypes had more similar microbiomes. This pattern of phylosymbiosis could be explained by co-phylogeny in only two out of the nine most prevalent associated bacterial genera, Roseomonas and Rhodobacter. These phylogenetically associated genera could enrich the metabolic repertoire of Microcystis, for example by encoding the biosynthesis of complementary carotenoid molecules. In contrast, other colony-associated bacteria showed weaker signals of co-phylogeny, but stronger evidence of horizontal gene transfer with Microcystis. These observations suggest that acquired genes are more likely to be retained in both partners (Microcystis and members of its microbiome) when they are loosely associated, whereas one gene copy is sufficient when the association is physically tight and evolutionarily long-lasting. Conclusions We have introduced a method for culture-free isolation of single colonies from nature followed by metagenomic sequencing, which could be applied to other types of microbes. Together, our results expand the known genetic diversity of both Microcystis and its microbiome in natural settings, and support their long-term, specific, and potentially beneficial associations.

scholarly journals Two organic carbon application rates to control inorganic nitrogen in minimal water exchange, biofloc, shallow water, shrimp nursery systems

2017 ◽  
Vol 14 ◽  
pp. 1-7
Author(s):  
Jack Crockett ◽  
Addison Lawrence
Keyword(s):  
Organic Carbon ◽  
Quantitative Method ◽  
Heterotrophic Bacteria ◽  
Inorganic Nitrogen ◽  
Ammonia Nitrogen ◽  
Microbial Conversion ◽  
Application Rates ◽  
Reactive Carbon ◽  
Water Replacement ◽  
Total Ammonia

The objectives of this study were to develop and test a quantitative method for reactive carbon application to control inorganic nitrogen, and to compare the effect of carbon application using 40% and 60% microbial conversion efficiency (MCE) while leaving a residual 11.3 mg/l nitrate nitrogen (NO3-N) level. The organic carbon requirement was based on the carbon to nitrogen ratio of the elemental composition of microbial cells. The source of supplemental organic carbon was shortchained fructooligosaccharide (scFOS). Correction for moisture was duplicated on the first 2 days of scFOS application, so the actual efficiency rates were 35.1% and 58.3%. The proposed carbon quantitative method was effective in predicting the amount of carbon required to control inorganic nitrogen. Both 35.1% MCE and 58.3% MCE maintained total ammonia nitrogen (TAN) and nitrite nitrogen (NO2-N) at desired levels of equal to or less than 2.3 mg/l and 3.1 mg/l, respectively. The amount of carbon applied using 35.1% MCE was higher than with 58.3% MCE. e 58.3% MCE treatment resulted in slightly higher NO3-N levels than 35.1 % MCE. The most toxic species of inorganic nitrogen, TAN and NO2-N, are assimilated by heterotrophic bacteria before NO3-N, permitting decreased reactive carbon input and water quality improvement. The benefits of 58.3% MCE vs. 35.1% MCE were lower organic loading, reduced water replacement, and decreased costs. The total water replacement associated with biofloc control was 0.24% using 35.1% MCE and 0% using 58.3% MCE. After a culture period of 14 days the mean weight was 65.5 mg and 61.9 mg for 31.5% MCE and 58.1% MCE, respectively, and a survival of 79.5% for both MCE’s.

scholarly journals Isolation of axenic cyanobacterium and the promoting effect of associated bacterium on axenic cyanobacterium

2020 ◽  
Author(s):  
Suqin Gao ◽  
Yun Kong ◽  
Jing Yu ◽  
Lihong Miao ◽  
Lipeng Ji ◽  
...  
Keyword(s):  
Heterotrophic Bacteria ◽  
Specific Interaction ◽  
Cyanobacterial Blooms ◽  
Organic Substrates ◽  
Promoting Effect ◽  
Associated Bacteria ◽  
Purification Technique ◽  
Harmful Cyanobacterial Blooms ◽  
Solid Liquid ◽  
Water Quality Deterioration

Abstract Background: Harmful cyanobacterial blooms have attracted wide attention all over the world as they cause water quality deterioration and ecosystem health issues. Microcystis aeruginosa associated with a large number of bacteria is one of the most common and widespread bloom-forming cyanobacteria that secret toxins. These associated bacteria are considered to benefit from organic substrates released by the cyanobacterium. In order to avoid the influence of associated heterotrophic bacteria on the target cyanobacteria for physiological and molecular studies, it is urgent to obtain an axenic M. aeruginosa culture and further investigate the specific interaction between the heterotroph and the cyanobacterium.Results: A traditional and reliable method based on solid-liquid alternate cultivation is carried out to purify the xenic cyanobacterium M. aeruginosa FACHB-905. On the basis of 16S rDNA gene sequences, two associated bacteria named strain B905-1 and strain B905-2, are identified as Pannonibacter sp. and Chryseobacterium sp. with a 99% and 97% similarity value, respectively. The axenic M. aeruginosa FACHB-905A (Microcystis 905A) is not able to form colonies on BG11 agar medium without the addition of strain B905-1, while it grows well in BG11 liquid medium. Although the presence of B905-1 is not indispensable for the growth of Microcystis 905A, B905-1 has a positive effect on promoting the growth of Microcystis 905A. Conclusions: The associated bacteria are eliminated by solid-liquid alternate cultivation method and the axenic Microcystis 905A is successfully purified. The associated bacterium B905-1 has the potential to promote the growth of Microcystis 905A. Moreover, the purification technique for cyanobacteria described in this study is potentially applicable to a wider range of unicellular cyanobacteria.

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