Colony formation of highly dispersed Microcystis aeruginosa by controlling extracellular polysaccharides and calcium ion concentrations in aquatic solution

To investigate the effects of lead(II) on the production of extracellular polysaccharides (EPS), including bound extracellular polysaccharides (bEPS) and soluble extracellular polysaccharides (sEPS), and the colony formation of Microcystis aeruginosa, cultures of M. aeruginosa were exposed to four concentrations (5.0, 10.0, 20.0 and 40.0 mg/L) of lead(II) for 10 d under controlled laboratory conditions. The results showed that 5.0 and 10.0 mg/L lead(II) stimulated M. aeruginosa growth throughout the experiment while 20.0 and 40.0 mg/L lead(II) inhibited M. aeruginosa growth in the first 2 d exposure and then stimulated it. As compared to the control group, significant increases in the bEPS and sEPS production were observed in 20.0 and 40.0 mg/L lead(II) treatments (P < 0.05). Large colony formations were not observed throughout the experiment. However, four tested concentrations of lead(II) could significantly promote the formation of small and middle colonies after 10 d exposure (P < 0.05), and 40.0 mg/L lead(II) had the best stimulatory effect. Lead(II) could stimulate bEPS production, which conversely promoted colony formation, suggesting that heavy metals might be contributing to the bloom-forming of M. aeruginosa in natural conditions.

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Impacts of different extracellular polysaccharides on colony formation and buoyancy of Microcystis aeruginosa

Annales de Limnologie - International Journal of Limnology ◽

10.1051/limn/2020026 ◽

2020 ◽

Vol 56 ◽

pp. 28

Author(s):

Kai Wei ◽

Yoshimasa Amano ◽

Motoi Machida

Keyword(s):

Microcystis Aeruginosa ◽

Colony Size ◽

Colony Formation ◽

Culture Medium ◽

Divalent Metal ◽

Extracellular Polysaccharides ◽

Size Analysis ◽

Light Conditions ◽

Divalent Metal Cations ◽

Calcium And Magnesium

On the surface of Microcystis cells, there is a carbohydrate called extracellular polysaccharides (EPS) playing a significant role in the colony formation of Microcystis. EPS consists of tightly cell-bound EPS (TB-EPS), and both of these substances are considered to be strongly related to the colony formation and buoyancy of Microcystis. In this study, Microcystis aeruginosa (strain: NIES-843) was used to examine the effects of EPS, TB-EPS, and divalent metal cations such as calcium and magnesium on the buoyancy and colony formation of M. aeruginosa NIES-843. Under various light conditions, the addition of TB-EPS into the culture medium induced M. aeruginosa NIES-843 to obtain high buoyancy at concentrations of Ca2+ and Mg2+ concentrations of 10 mg/L and 30 mg/L, respectively. Under the absence of light, the addition of EPS could lead M. aeruginosa to form a colony and obtain buoyancy, and the addition of TB-EPS could not significantly change the buoyancy of M. aeruginosa NIES-843. The colony size analysis showed that at the same cationic concentration, the addition of TB-EPS could induce M. aeruginosa to form the largest colony and present strong buoyancy. This study suggested that temperature and illumination are conducive to colony formation and present higher buoyancy of M. aeruginosa.

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CLINICAL ESTIMATION AND SIGNIFICANCE OF CALCIUM-ION CONCENTRATIONS IN THE BLOOD

The American Journal of the Medical Sciences ◽

10.1097/00000441-193505000-00001 ◽

1935 ◽

Vol 189 (5) ◽

pp. 21-612 ◽

Cited By ~ 164

Author(s):

FRANKLIN C. MCLEAN ◽

A. BAIRD HASTINGS

Keyword(s):

Calcium Ion ◽

Ion Concentrations

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Sodium-Induced Calcium Flux via Mitochondrial NCE is Dissimilar when Derived from Matrix and Extra-Matrix Calcium Ion Concentrations

Biophysical Journal ◽

10.1016/j.bpj.2011.11.891 ◽

2012 ◽

Vol 102 (3) ◽

pp. 164a

Author(s):

Christoph A. Blomeyer ◽

David F. Stowe ◽

Ranjan K. Pradhan ◽

Jason N. Bazil ◽

Ranjan K. Dash ◽

...

Keyword(s):

Calcium Ion ◽

Calcium Flux ◽

Ion Concentrations

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Constituent elements of insoluble and non-volatile particles during the Last Glacial Maximum exhibited in the Dome Fuji (Antarctica) ice core

Journal of Glaciology ◽

10.3189/002214309788816696 ◽

2009 ◽

Vol 55 (191) ◽

pp. 552-562 ◽

Cited By ~ 17

Author(s):

Yoshinori Iizuka ◽

Takayuki Miyake ◽

Motohiro Hirabayashi ◽

Toshitaka Suzuki ◽

Sumito Matoba ◽

...

Keyword(s):

Last Glacial Maximum ◽

Calcium Ion ◽

Ice Core ◽

Ice Cores ◽

Glacial Maximum ◽

Ion Concentrations ◽

Last Glacial ◽

Insoluble Particles ◽

Almost All ◽

Constituent Elements

AbstractIn order to find environmental signals based on the dust and calcium-ion concentrations in ice cores, we determine the constituent elements of residue particles obtained after melting ice samples. We have designed a sublimating system that operates at −45°C, below the eutectic temperatures of major salts. This system permits us to obtain a great many non-volatile particles. After studying the non-volatile particles, we immersed them in water to remove soluble particles and compounds. We thereby analyzed a total of 1272 residue particles (from the melted sample), 2418 non-volatile particles (after sublimation) and 1463 insoluble particles taken from five sections of Last Glacial Maximum ice from the Dome Fuji (Antarctica) ice core. Their constituent elements were determined by scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM-EDS) and compared to the dust, calcium-ion and sodium-ion concentrations measured by ion chromatography. Our results indicate that >99.9% of the insoluble particles contain silicon but no sulfur, nitrogen or chlorine. A significant number of the non-volatile particles, however, contain sulfur and chlorine. We conclude that insoluble dust consists mostly of silicate, that almost all calcium ions originate from calcium sulfate and that almost all sodium ions originate from sodium sulfate and sodium chloride.

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