scholarly journals Arsenic Accumulation and Biotransformation Affected by Nutrients (N and P) in Common Blooming-Forming Microcystis wesenbergii (Komárek) Komárek ex Komárek (Cyanobacteria)

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 245
Author(s):  
Zhe Xiao ◽  
Xiaochuang Li ◽  
Shouliang Huo
Keyword(s):  
Biogeochemical Cycles ◽  
Nutrient Concentrations ◽  
Freshwater Systems ◽  
Bg11 Medium ◽  
Arsenic Accumulation ◽  
High Nutrient ◽  
Extracellular Level ◽  
Microcystis Wesenbergii ◽  
High Concentrations ◽  
High Nutrient Concentration

Arsenic accumulation and biotransformation in algae was mostly carried out in a medium that contained far higher nutrient concentrations than that in natural freshwaters. The obtained results might have limited environmental validity and result in a failure to describe authentic arsenic biogeochemical cycles in natural freshwater systems. To validate the assumption, arsenic accumulation, and biotransformation in common bloom forming Microcystis wesenbergii was performed under a high nutrient concentration in BG11 medium (N = 250 mg/L, P = 7.13 mg/L), and adjusted low nutrients that mimicked values in natural freshwaters (N = 1.5 mg/L, P = 0.3 mg/L). The growth rate and maximum M. wesenbergii cell density were much lower in the high nutrient set, but more inhibition was shown with increasing ambient iAs(V) concentrations both in the high and low nutrient sets. The proportion of intracellular contents in total arsenicals decreased with increasing iAs(V) concentrations in both high and low nutrient sets but increased with incubation time. Intracellular iAs(III) was not found in the high nutrient set, while it formed high concentrations that could be comparable to that of an extracellular level in the low nutrient set. M. wesenbergii could methylate arsenic, and a higher proportion of organoarsenicals was formed in the low nutrient set. Lower intracellular MMA(V) and DMA(V) concentrations were found in the high nutrient set; contrarily, they presented a higher concentration that could be comparable to the extracellular ones in the low nutrient set. The results demonstrated that different nutrient regimes could affect arsenic accumulation and biotransformation in M. wesenbergii, and low nutrient concentrations could inhibit the excretion of iAs(III), MMA(V) and DMA(V) out of cells. Further investigations should be based on natural freshwater systems to obtain an authentic arsenic accumulation and biotransformation in cyanobacteria.

The Source of Muddy Odor in Bream (Abramis brama) from the Porvoo Sea Area (Gulf of Finland)

1979 ◽  
Vol 36 (8) ◽  
pp. 883-890 ◽  
Author(s):  
Per-Edvin Persson
Keyword(s):  
Abramis Brama ◽  
Blue Green Alga ◽  
Bream Abramis Brama ◽  
High Nutrient ◽  
Off Flavors ◽  
Odor Compounds ◽  
High Concentrations ◽  
High Nutrient Concentration ◽  
Oscillatoria Agardhii ◽  
Sea Area

The study area was a shallow, extremely eutrophic, somewhat brackish water bay on the south coast of Finland. Muddy odor in bream (Abramis brama) was significantly correlated with the amount of the blue-green alga Oscillatoria agardhii occurring in the phytoplankton. Cultures dominated by this alga contained the muddy odor compound geosmin. The high concentrations of O. agardhii in the study area were caused by several interacting factors, of which the high nutrient concentration and the temperature of the water seemed to be especially important. Odoriferous actinomycetes isolated from the water produced the muddy odor compounds geosmin and 2-methylisoborneol, but there seemed to be a lag time of several weeks between maximal concentrations of actinomycetes and development of off-flavors in the fish. Key words: geosmin, 2-methylisoborneol, Oscillatoria agardhii, actinomycetes, flavor, fish, eutrophication

Effect of dietary nutrient concentration on the performance of hens beginning lay in early summer

1986 ◽  
Vol 26 (4) ◽  
pp. 405 ◽  
Author(s):  
AS Pell ◽  
RW Polkinghorne
Keyword(s):  
Egg Production ◽  
Nutrient Concentration ◽  
Early Summer ◽  
Nutrient Concentrations ◽  
Egg Mass ◽  
Meat Meal ◽  
High Nutrient ◽  
Dietary Nutrient ◽  
Metabolisable Energy ◽  
High Nutrient Concentration

Hens of 2 laying strains were fed ad libitum from 20 to 72 weeks of age on 3 diets of different nutrient concentration. The start of lay coincided with the onset of the hot summer. During summer, birds on the diet with high nutrient concentration (HNC, 19% protein, 12.6 MJ metabolisable energy (ME)/kg) had significantly higher intakes of ME (3% higher) and other nutrients than did those on the diets of medium (MNC, 18% protein, 11.7 MJ ME/kg) and low (LNC, 16% protein, 11.4 MJ ME/kg) nutrient concentration. Egg weight. egg mass and feed efficiency were greater on the HNC diet than on the MNC and LNC diets. Birds on the HNC diet produced more eggs (10% more) than those on the LNC diet. Over the cooler periods, feed intakes were inversely related to energy level, with no dietary effects on egg production. It is concluded that grain- and meat meal-based diets of low nutrient concentrations are unlikely to support maximum performance in early lay in hot conditions and that increased dietary nutrient concentrations can improve performance via increased nutrient intake.

scholarly journals Nutrient Concentration and Fruit Thinning Affect Shelf Life of Long English Cucumber

HortScience ◽  
1991 ◽  
Vol 26 (10) ◽  
pp. 1299-1300 ◽  
Author(s):  
W.C. Lin ◽  
D.L. Ehret
Keyword(s):  
Shelf Life ◽  
Cucumis Sativus ◽  
Nutrient Concentration ◽  
Fruit Color ◽  
Main Stem ◽  
Nutrient Concentrations ◽  
Fruit Thinning ◽  
High Nutrient ◽  
Marketable Fruit ◽  
High Nutrient Concentration

Long English cucumber (Cucumis sativus L.) plants were treated with one of three nutrient concentrations in combination with two fruit thinning treatments forming a 3 × 2 factorial greenhouse experiment. High nutrient concentration enhanced fruit color at harvest and prolonged shelf life but reduced marketable fruit per plant. Thinning of one-third of the fruit from the main stem and laterals had a similar effect. Cucumbers harvested from the upper canopy generally had longer shelf life than those from the lower canopy. Shelf life was correlated with fruit color at harvest.

P-limitation drives changes in DOM production by aquatic bacteria

2020 ◽  
Vol 85 ◽  
pp. 35-46
Author(s):  
SK Thompson ◽  
JB Cotner
Keyword(s):  
Organic Matter ◽  
Optical Properties ◽  
Heterotrophic Bacteria ◽  
Organic Phosphorus ◽  
Phosphorus Limitation ◽  
Biogeochemical Cycles ◽  
Nutrient Concentrations ◽  
Carbon Limitation ◽  
Freshwater Systems ◽  
P Limitation

Heterotrophic bacteria are key biogeochemical regulators in freshwater systems. Through both decomposition and production of organic matter, bacteria link multiple biogeochemical cycles together. While there has been a significant amount of work done on understanding the role of microbes in the aquatic carbon cycle, important linkages with other biogeochemical cycles will require more information about how organic matter transformations impact other nutrients, such as phosphorus. In this study, we conducted a culture-based laboratory experiment to examine the production of dissolved organic matter (DOM) by heterotrophic bacteria under varied nutrient conditions. In addition to quantifying the production of dissolved organic carbon (DOC), we also measured the production of dissolved organic phosphorus (DOP) and characterized the microbially produced organic matter using optical properties. Results demonstrated that measurable amounts of DOC and DOP were produced by heterotrophic bacteria under nutrient regimes ranging from carbon-limitation to strong phosphorus-limitation. Additionally, optical characterization of DOM revealed that the organic matter produced by bacteria grown under high phosphorus conditions was highly aromatic with similar optical properties to terrestrially derived organic matter. Overall, these findings suggest that heterotrophic bacteria can be important producers of organic matter in freshwaters and that continued trends of increased nutrient concentrations (eutrophication) may fundamentally change the composition of microbially produced organic matter in freshwater systems.

Nutrient Input and Trophic Status of the “Neue Donau”, a High-Water Control System along the River Danube in Vienna, Austria

1990 ◽  
Vol 22 (5) ◽  
pp. 137-144 ◽  
Author(s):  
M. T. Dokulil ◽  
G. A. Janauer
Keyword(s):  
Water Quality ◽  
Control System ◽  
Trophic Status ◽  
High Water ◽  
Nutrient Concentrations ◽  
Nutrient Input ◽  
Water Control ◽  
Trophic Conditions ◽  
River Danube ◽  
High Nutrient

The system “Neue Donau” functions as a control system for high waters of the river Danube and is an important recreational area for many people. Water quality and trophic status of the water body is thereforeof prime importance. The high nutrient concentrations of the river Danube (P-tot 238±41µg/l, N-tot 2.53±0.78 mg/l) reach the system via groundwater seepage. Present conditions in the basin of Neue Donau are,as a result of this nutrient in-flux,eutrophic to hypertrophic. Average values during the summer period have declined from 366 µg/l total phosphorus to 78 µg/l, and from 86 µg/l chlorophyll-a tol7µg/l between the years 1985 and 1988. However, a dam which is planned in the river at Vienna will permanently raise the water level of the river thus increasing the the groundwater flow in the direction to the Neue Donau and therefore the nutrient input which will enhance trophic conditions in the impoundment. Since macrophytes play an important role in one part of the system macrophyte management together with measures along the river are some of the suggested strategies to keep the system Neue Donau at acceptable trophic conditions and good water quality.

scholarly journals On the Internalisation, Intraplasmodial Carriage and Excretion of Metallic Nanoparticles in the Slime Mould, Physarum Polycephalum

2011 ◽  
Vol 3 (3) ◽  
pp. 1-14 ◽  
Author(s):  
Richard Mayne ◽  
David Patton ◽  
Ben de Lacy Costello ◽  
Andrew Adamatzky ◽  
Rosemary Camilla Patton
Keyword(s):  
Metallic Nanoparticles ◽  
Physarum Polycephalum ◽  
Nutrient Concentration ◽  
Laboratory Experiments ◽  
Micro Scale ◽  
Naked Eye ◽  
High Nutrient ◽  
High Nutrient Concentration ◽  
Silver Metal ◽  
Plasmodium Of Physarum Polycephalum

The plasmodium of Physarum polycephalum is a large single cell visible with the naked eye. When inoculated on a substrate with attractants and repellents the plasmodium develops optimal networks of protoplasmic tubes which span sites of attractants (i.e. nutrients) yet avoid domains with a high nutrient concentration. It should therefore be possible to program the plasmodium towards deterministic adaptive transformation of internalised nano- and micro-scale materials. In laboratory experiments with magnetite nanoparticles and glass micro-spheres coated with silver metal the authors demonstrate that the plasmodium of P. polycephalum can propagate the nano-scale objects using a number of distinct mechanisms including endocytosis, transcytosis and dragging. The results of the authors’ experiments could be used in the development of novel techniques targeted towards the growth of metallised biological wires and hybrid nano- and micro-circuits.

scholarly journals Fluctuated water depth with high nutrient concentrations promote the invasiveness of Wedelia trilobata in Wetland

2019 ◽  
Vol 10 (2) ◽  
pp. 832-842 ◽  
Author(s):  
Jianfan Sun ◽  
Qaiser Javed ◽  
Ahmad Azeem ◽  
Ikram Ullah ◽  
Muhammad Saifullah ◽  
...  
Keyword(s):  
Water Depth ◽  
Nutrient Concentrations ◽  
Wedelia Trilobata ◽  
High Nutrient

Major cyanobacterial bloom in the Barwon-Darling River, Australia, in 1991, and underlying limnological conditions

1996 ◽  
Vol 47 (4) ◽  
pp. 643 ◽  
Author(s):  
LC Bowling ◽  
PD Baker
Keyword(s):  
New South ◽  
Cyanobacterial Bloom ◽  
Low Flow ◽  
Nutrient Concentrations ◽  
Mouse Bioassay ◽  
Contributing Factors ◽  
South Wales ◽  
High Ammonia ◽  
High Nutrient ◽  
Very High

The occurrence of a severe cyanobacterial bloom is described. This bloom affected almost 1000 km of the Barwon-Darling River, New South Wales, Australia, in November and December 1991 and was dominated by Anabaena circinalis Rabenhorst. This cyanobacterium was present in concentrations of around half a million cells per millilitre at some localities during its peak in mid November. Moderate to very high toxicity was demonstrated by mouse bioassay at many localities during this time. The bloom was attributed to very low flow conditions and high nutrient concentrations, especially of total phosphorus. However, warm water temperatures, elevated pH, reduced turbidity, and improved water transparency would also have been contributing factors. Very high ammonia concentrations were also observed during the bloom. The bloom declined during December and was eventually flushed from the river by increased flows following heavy catchment rainfall between mid December and early January.

scholarly journals Nutrient enrichment effect on macroinvertebrates in a lowland stream of Argentina

2015 ◽  
Vol 105 (2) ◽  
pp. 228-234 ◽  
Author(s):  
Agustina Cortelezzi ◽  
Carolina Ocón ◽  
María V. López van Oosterom ◽  
Rosana Cepeda ◽  
Alberto Rodrigues Capítulo
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Global Climate ◽  
Nitrogen Concentration ◽  
Nutrient Concentrations ◽  
Phosphorus Concentration ◽  
Lowland Stream ◽  
Pampean Streams ◽  
High Concentrations ◽  
Intensive Land Use

ABSTRACT One of the most important effects derived from the intensive land use is the increase of nutrient concentration in the aquatic systems due to superficial drainage. Besides, the increment of precipitations in South America connected to the global climate change could intensify these anthropic impacts due to the changes in the runoff pattern and a greater discharge of water in the streams and rivers. The pampean streams are singular environments with high natural nutrient concentrations which could be increased even more if the predictions of global climate change for the area are met. In this context, the effect of experimental nutrient addition on macroinvertebrates in a lowland stream is studied. Samplings were carried out from March 2007 to February 2009 in two reaches (fertilized and unfertilized), upstream and downstream from the input of nutrients. The addition of nutrients caused an increase in the phosphorus concentration in the fertilized reach which was not observed for nitrogen concentration. From all macroinvertebrates studied only two taxa had significant differences in their abundance after fertilization: Corbicula fluminea and Ostracoda. Our results reveal that the disturbance caused by the increase of nutrients on the benthic community depends on basal nutrients concentration. The weak response of macroinvertebrates to fertilization in the pampean streams could be due to their tolerance to high concentrations of nutrients in relation to their evolutionary history in streams naturally enriched with nutrients. Further research concerning the thresholds of nutrients affecting macroinvertebrates and about the adaptive advantages of taxa in naturally eutrophic environments is still needed. This information will allow for a better understanding of the processes of nutrient cycling and for the construction of restoration measures in natural eutrophic ecosystems.

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