Estimating the Precision of Filamentous Blue-Green Algae Cell Concentration From a Single Sample

Laslett, G. M.; Clark, R. M.; Jones, Gary J.

doi:10.1002/(sici)1099-095x(199707)8:4<313::aid-env253>3.0.co;2-v

Cited by 17 publications

(7 citation statements)

References 22 publications

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“…Cell counts were carried out to a minimum precision of 20%. Precision is defined as the ratio of the standard error to the estimate of the mean and is essentially the chance variability about the observed mean value (Laslett et al, 1998).…”

Section: Methodsmentioning

confidence: 99%

Using Coagulation, Flocculation, and Settling to Remove Toxic cyanobacteria

Drikas¹,

Chow²,

House³

et al. 2001

Journal AWWA

148

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Cyanobacteria (blue‐green algae) produce toxins and tastes and odors that can significantly impair water quality. The removal of cyanobacterial cells without cell damage could significantly reduce the concentration of tastes, odors, and toxic cell metabolites present in treated water. Cultured cyanobacterium, hepatotoxic Microcystis aeruginosa, was mixed with reservoir water to simulate water entering a treatment plant during an algal bloom. A bench‐top jar‐test apparatus (flocculation) and a full‐scale pilot plant (flocculation–sedimentation–filtration) rated at 600 mL/min were used to evaluate the effectiveness of conventional water treatment processes in removing cyanobacterial cells. Removal of cells by flocculation using a jar‐test apparatus with aluminum sulfate dosed at concentrations used in water treatment practice varied between 70 and 83%. Results obtained from the pilot experiment indicated 99.9% of the cells were removed. More important, no additional release of microcystin (toxin) was found in the finished water.

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Section: Methodsmentioning

confidence: 99%

Using Coagulation, Flocculation, and Settling to Remove Toxic cyanobacteria

Drikas¹,

Chow²,

House³

et al. 2001

Journal AWWA

148

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“…Cell densities were determined using a precalibrated Lund Cell (Lund et al, 1958). At least 50 trichomes were counted to keep the coefficient of variation of the mean population estimate to ±28% or less (Laslett et al, 1997). The cell division rate ( G ) was determined from the slope of the log 2 transformed cell density against time (Guillard, 1973).…”

Section: Methodsmentioning

confidence: 99%

Phenotypical variation in a toxic strain of the phytoplankter, Cylindrospermopsis raciborskii (nostocales, cyanophyceae) during batch culture

Hawkins¹,

Putt²,

Falconer³

et al. 2001

Environmental Toxicology

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A nonaxenic strain of Cylindrospermopsis raciborskii Woloszynska (AWT 205) was grown in batch culture, with and without nitrate as the primary N source. Rapid log-phase growth with nitrate was 1.0 doubling/day versus 0.3 doubling/day without nitrate. Cylindrospermopsin (CYN) production was measured by HPLC. The rate of intracellular CYN production matched cell division rate for both the diazotrophies at cell densities less than 10(7) cell/ml. At cell density > 10(7) cell/ml, additional resource limitation in batch culture slowed log-phase growth to 0.04 division/day and cell division and CYN production decoupled. Intracellular CYN concentration increased at a rate of 0.08 doubling/day, twice the cell division rate. Extracellular CYN as a proportion of the total CYN increased from 20% during the rapid growth phase, to 50% during the slow growth phase. The total CYN yield from cultures grown out to stationary phase (55 days) exceeded 2 mg CYN/I. C. raciborskii cells in log-phase growth, exposed to 1 ppm copper (as copper sulphate), lysed within 24 hours. After copper treatment, all CYN was in the filterable fraction. These findings imply that in naturally occurring blooms of C. raciborskii, the movement of intracellular CYN into solution will be the greatest during stationary phase, when intracellular concentrations are highest and cell lysis is more frequent. The application of algicides that promote cell lysis will exacerbate this effect.

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“…Cell abundance was determined as follows: The 5-m integrated samples, preserved in acid Lugol's solution, were concentrated lo-fold by sedimentation, then microscopically counted to species level using a Sedgwick-Rafter counting chamber. At least 23 cyanobacterial or diatom filaments were counted (although individual cells were also counted) to give a maximum standard error of 2330% (Laslett et al 1997).…”

Section: Methodsmentioning

confidence: 99%

Transitions between Auhcoseira and Anabaena dominance in a turbid river weir pool

Sherman

Webster

Jones

et al. 1998

Limnology & Oceanography

Self Cite

138

128

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The transitions between the diatoms Aulacoseira spp. (Melosira) and the cyanobacteria Anabaena spp. as dominant phytoplankton species in a turbid-river weir pool are shown to depend directly on the establishment or destruction of persistent thermal stratification. A transition from high to low flow through the pool resulted in the establishment of persistent thermal stratification, causing Aulacoseira to sink out of the euphotic zone at a speed of 0.95 m d-l. Concurrently, the slightly buoyant Anabaena grew within the euphotic zone with a specific growth rate of 0.37 d-l, climaxing after approximately 14 d at a population of 20,000-30,000 cells ml I, at which point its biomass may have been limited by the availability of phosphorus. The stratification thus caused the phytoplankton population to separate into two distinct layers, with Anabaena occupying the illuminated surface layer and Aulacoseiru found only in the lower layer below the euphotic depth. Under stratified conditions, the ratio of the surface layer depth to euphotic depth, z,, : z,,, was approximately 1, whereas for a mixed water column that ratio was >3. Access to light appeared to be the main factor determining the dominant phytoplankton species. of the weir. Thanks also to Wendy Minato and Rhonda Smith, who uncomplainingly counted the algal samples, and to Mark Fink for the chemical analyses.

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Estimating the Precision of Filamentous Blue-Green Algae Cell Concentration From a Single Sample

Cited by 17 publications

References 22 publications

Using Coagulation, Flocculation, and Settling to Remove Toxic cyanobacteria

Using Coagulation, Flocculation, and Settling to Remove Toxic cyanobacteria

Phenotypical variation in a toxic strain of the phytoplankter, Cylindrospermopsis raciborskii (nostocales, cyanophyceae) during batch culture

Transitions between Auhcoseira and Anabaena dominance in a turbid river weir pool

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