The effect of field-collected biofilms on the toxicity of copper to a marine microalga (Tetraselmis sp.) in laboratory bioassays

Standard algal growth rate inhibition bioassays can lack environmental realism and may over- or underestimate metal bioavailability in natural systems. In aquatic environments, algal species interact with other biota, including other algae, bacteria and biofilms. In this work, the feasibility of incorporating marine biofilms into 72 h algal growth inhibition toxicity tests was explored. The effects of copper on Tetraselmis sp. were tested in the absence and presence of characterised field-collected biofilms. We hypothesised that the addition of biofilm would prevent copper toxicity to the alga primarily through interactions of the metal with other cells and biofilm exudates. The sensitivity of Tetraselmis sp. to copper (based on 72 h IC50 values; the copper concentration to inhibit population growth by 50%) in the presence of a blended biofilm inoculum varied 2-fold and was independent of the amount of biofilm added. However, increases in IC10 and IC20 values indicated some amelioration of copper toxicity. When intact biofilms were added to the bioassays, amelioration of toxicity was more consistent, probably due to increased binding of copper to cell surfaces or exudates. Difficulties in characterising biofilms and distinguishing that material from the test alga need to be overcome before biofilms can be routinely incorporated into laboratory bioassays.

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Development and application of a simple procedure for toxicity testing using immobilized algae

Water Science & Technology ◽

10.2166/wst.1996.0089 ◽

1996 ◽

Vol 33 (6) ◽

pp. 129-138 ◽

Cited By ~ 10

Author(s):

Mohammad I. Abdel-Hamid

Keyword(s):

Simple Procedure ◽

Algal Growth ◽

Toxicity Testing ◽

Dry Weight ◽

Toxicity Assessment ◽

Response Curves ◽

Response Parameter ◽

Test Alga ◽

Almost All ◽

Immobilized Algae

A simple microplate technique was adopted for toxicity assessment of a number of pesticides including six herbicides (Atrazine, Dichloroprop, Glyphosphate, Chlorsulfuron, MCPA, and Simazine), an insecticide (Dimethoate) and a fungicide (Propiconazol). Growth response of free and immobilized cultures of the green chlorococcal algae Selenastrum capricornumtum to different treatments of these pesticides was tested and compared. The biotests were carried out under conditions optimal for the growth of the test alga. Algal growth was exposed in terms of dry weight, and was employed as the toxicity-response parameter. Dose-response curves were used to calculate the toxicity of the tested compounds in terms of EC50. Based on EC50 values, the responses of both immobilized and free cultures were quite similar for almost all the treatments. The technique facilitated the visual detection of the lowest toxic concentration giving no detectable algal growth (EC100). The technique is quite simple, rapid, practical, accurate, and space saving. It suggested that batteries of immobilized algae could replace free cultures in studies of toxicity testing.

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Enhancement of Hydrocarbon Productivity of Botryococcus braunii by an Adenine Type Phytohormone

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.512-515.397 ◽

2012 ◽

Vol 512-515 ◽

pp. 397-400

Author(s):

Jun Zhi Liu ◽

Ya Ming Ge ◽

Guang Ming Tian

Keyword(s):

Growth Rate ◽

Low Dose ◽

Algal Growth ◽

Botryococcus Braunii ◽

Biofuel Production ◽

Carotenoid Content ◽

Algae Biofuels ◽

Hydrocarbon Content ◽

Algal Growth Rate ◽

Hydrocarbon Productivity

This study examined the effects of an adenine-type cytokinin 6-benzylaminopurine (6-BA) on the growth and metabolism characteristics of Botryococcus braunii, one of the most promising oil-rich algae for biofuel production. The results showed that 6-BA of low dose (0.1-1.0 mg L-1) would enhance the algal growth rate and biochemical synthesis, whereas too much (5.0 mg L-1) would be lethally toxic for B. braunii. Noticingly, though the maximum algal growth rate, chlorophyll and β-carotenoid content were observed in the treatment with 0.5 and/or 1.0 mg L-1 6-BA, both the maximum algal hydrocarbon content and the highest hydrocarbon productivity were observed in the treatment with 0.1 mg L-1 6-BA, which were respectively 2.45 and 3.48 times of the control (39.1% vs. 16.0%, 546 mg L-1 vs. 157 mg L-1). This finding has great implications for improving algae biofuels production by phytohormone.

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Increased fecundity of the cladoceran Moinodaphnia macleayi on a diet supplemented with a green alga, and its use in uranium toxicity tests

Marine and Freshwater Research ◽

10.1071/mf9930389 ◽

1993 ◽

Vol 44 (3) ◽

pp. 389 ◽

Cited By ~ 13

Author(s):

RV Hyne ◽

A Padovan ◽

DL Parry ◽

SM Renaud

Keyword(s):

Unsaturated Fatty Acids ◽

Lipid Fraction ◽

Algal Species ◽

Cichlid Fish ◽

Dry Weight ◽

Scenedesmus Quadricauda ◽

Toxicity Tests ◽

Ankistrodesmus Falcatus ◽

Algal Diets ◽

Chlamydomonas Sp

The effects of two synthetic diets and four algal diets on the survival and fecundity of Moinodaphnia macleayi for use in life-cycle toxicity tests were determined. The synthetic foods were a suspension of blended cichlid fish pellets with powdered alfalfa, either prepared fresh or fermented in natural water for 3 days. The algae, isolated from the habitat of M. rnacleayi in the Alligator Rivers Region, were Selenastrum sp., Ankistrodesmus (falcatus?), Scenedesmus quadricauda and a Chlamydomonas sp. Each alga was tested alone or as a supplement to the fermented synthetic food. The diet that supported the greatest number of young and the highest survival rate over a 5-day period was a combination of the fermented synthetic food and Chlamydomonas sp. Analysis of the fatty acid composition of the lipid fraction of the four algal species showed that Chlamydomonas sp., Selenastrum sp. and Scenedesmus quadricauda had significant concentrations of the highly unsaturated fatty acids 18 : 2(n-6), 18 : 3(n-6) and 18: 3(n-3). In terms of size and dry weight, Chlamydomonas sp. was the smallest of the algal cells studied. The toxicity of uranium to M. macleayi survival, determined under standard conditions, was a lowest-observed-effect concentration (LOEC) of 200 �g L-1 after 48 h and 25 �g L-1 after 5 days.

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A comparative study of photosynthetic unit models for algal growth rate and fluorescence prediction under light/dark cycles

Algal Research ◽

10.1016/j.algal.2017.03.028 ◽

2017 ◽

Vol 24 ◽

pp. 227-236 ◽

Cited By ~ 3

Author(s):

Paul Rudnicki ◽

Xi Gao ◽

Bo Kong ◽

R. Dennis Vigil

Keyword(s):

Growth Rate ◽

Comparative Study ◽

Algal Growth ◽

Photosynthetic Unit ◽

Algal Growth Rate

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Enhancement of algal growth in Cyanophyta–bacteria systems by carbonaceous compounds

Canadian Journal of Microbiology ◽

10.1139/m71-052 ◽

1971 ◽

Vol 17 (3) ◽

pp. 303-314 ◽

Cited By ~ 44

Author(s):

Willy Lange

Keyword(s):

Atmospheric Carbon Dioxide ◽

Algal Species ◽

Algal Growth ◽

Limiting Factor ◽

Growth Enhancement ◽

Organic Additives ◽

Blue Green Algae ◽

Essential Trace Elements ◽

Carbon Compounds ◽

Algal Photosynthesis

Planktonic blue-green algae are always associated with bacteria. This association leads to enhanced or abundant algal growth when atmospheric carbon dioxide becomes a limiting factor and bacteria-assimilable carbonaceous matter is added. The study was carried out with 12 bacteria-associated blue-green species and 22 aliphatic, bacteria-assimilable carbon compounds. A normal, phosphate-rich Zehnder–Gorham culture medium (No. 11) was used. The bacterial assimilation of the aliphatic matter apparently leads to the production of CO2, which accelerates algal photosynthesis. The observed growth effects are not specific for a particular algal species. They appear to be specific mainly for the bacteria which happen to be associated with the algal cells. Similar growth enhancement was observed when the atmosphere was enriched with 0.5% CO2. With this augmented supply of atmospheric CO2, however, the enhancing effect of organic matter disappeared. The presence of the organic additives also appears to delay bacterial assimilation of organic chelating agents which have been added to keep iron and essential trace elements accessible to the algae in an alkaline medium. Axenic cultures of those algal species which cannot use added carbonaceous compounds did not show any effect of the additive. The results suggest that bacteria-assimilable carbon compounds may be one of the factors leading to algal bloom in lakes and ponds, especially when growth is not limited by the supply of phosphorus or other inorganic elements.

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Algal growth rate fluctuations observed under uniform ambient test conditions using static and semicontinuous assay techniques

Environmental Toxicology and Chemistry ◽

10.1002/etc.5620170317 ◽

1998 ◽

Vol 17 (3) ◽

pp. 460-467 ◽

Cited By ~ 2

Author(s):

Richard B. Benjamin ◽

Ray Brown ◽

Merideth Fraizer ◽

Bruce M. Joab ◽

Ryan E. Casey ◽

...

Keyword(s):

Growth Rate ◽

Algal Growth ◽

Test Conditions ◽

Algal Growth Rate

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ASSESSMENT OF THE EFFECT OF WATER QUALITY ON COPPER TOXICITY INHYALELLA AZTECA

AECL Nuclear Review ◽

10.12943/anr.2015.00040 ◽

2015 ◽

Vol 4 (1) ◽

pp. 83-90 ◽

Cited By ~ 1

Author(s):

Laura Richards ◽

Stephanie Walsh ◽

Carmen Shultz ◽

Marilyne Stuart

Keyword(s):

Ionic Strength ◽

River Water ◽

Sediment Toxicity ◽

River Sediments ◽

Copper Toxicity ◽

Copper Tolerance ◽

Toxicity Tests ◽

Water Type ◽

Ottawa River ◽

Sediment Toxicity Tests

The objective of this study was to test the hypothesis that when standard artificial media 5-salt culture water (SAM-5S) is used to test sediment toxicity of much lower ionic-strength aquatic ecosystems, the resulting toxicity estimates are lower than if the tests had been conducted in water of comparable ionic strength. Results showed that this concern was unfounded for testing of copper toxicity to Hyalella azteca (H. azteca) in Ottawa River water. Sediment testing is often conducted using a standard water that is prepared in the laboratory. However, this water may have an ionic strength that is different than local water bodies. It follows that laboratory results using the standard water may be unrepresentative. A study was undertaken to assess the copper tolerance of 2 strains of H. azteca in SAM-5S, diluted SAM-5S (similar in electrical conductivity to Ottawa River water), and Ottawa River water. Acute (96 h) copper toxicity tests were conducted with 9–16 day-old H. azteca. For a given water type, the 2 strains of H. azteca yielded comparable responses to copper. The highest copper tolerance was found in Ottawa River water (closely followed by SAM-5S), whereas the lowest copper tolerance was found in diluted SAM-5S. Our results suggest that sediment toxicity is not lowered by the higher ionic strength of SAM-5S and that sediment toxicity tests of Ottawa River sediments, conducted with SAM-5S, can be used to estimate the in situ toxicity of the sediments.

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Assimilable organic carbon formation from algogenic organic matter and its variation by chlorination

Water Science & Technology Water Supply ◽

10.2166/ws.2006.075 ◽

2006 ◽

Vol 6 (2) ◽

pp. 239-244 ◽

Cited By ~ 1

Author(s):

J. Kim ◽

S. Lee ◽

S. Xu ◽

M. Akiba ◽

M. Nomura ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Culture Medium ◽

Algal Species ◽

Algal Growth ◽

Carbon Formation ◽

Chlorination Process ◽

Assimilable Organic Carbon ◽

Extracellular Organic Matter ◽

Death Phase

The objective of this study is to assess the importance of algae and algogenic organic substances concerned with the formation of assimilable organic carbon (AOC) during algal growth and chlorination process. Laboratory tests were carried out using cultures of algal species (Phormidium tenue) with different culture medium, M-11 and CT. Extracellular organic matter (EOM) produced during the stationary phase and death phase of P. tenue (106 cells/mL) with M-11 culture medium led to significant increase of the AOC concentration, up to 100 times as high as its initial concentration. In case of CT culture medium containing a high DOC component, the AOC concentration did not increase significantly during P. tenue culture. The formation and removal of AOC derived from EOM and intercellular organic matter (IOM) by chlorination were also examined. The AOC concentration after chlorination of EOM and IOM became maximum with 2 mg/L of chlorine dosage while it decreased with increase of chlorine dosage when the dosage was higher than 2 mg/L, suggesting that necessary chlorine dosage to not form AOC is higher than 2 mg/L.

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Experimental Study of the Quantitative Impact of Flow Turbulence on Algal Growth

Water ◽

10.3390/w13050659 ◽

2021 ◽

Vol 13 (5) ◽

pp. 659

Author(s):

Haiping Zhang ◽

Yafei Cui ◽

Yuehong Zhang ◽

Hanling Xu ◽

Feipeng Li

Keyword(s):

Growth Rate ◽

Oxygen Evolution ◽

Microcystis Aeruginosa ◽

Algal Growth ◽

Turbulent Intensity ◽

Photosynthetic Oxygen Evolution ◽

Photosynthetic Oxygen ◽

Flow Turbulence ◽

Study Laboratory ◽

Algal Growth Rate

Flow turbulence has been widely accepted as one of the essential factors affecting phytoplankton growth. In this study, laboratory cultures of Microcystis aeruginosa in beakers were carried out under different turbulent conditions to identify the quantitative relationship between the algal growth rate and the turbulent intensity. The turbulent intensity (represented by energy dissipation rate, ε) was simulated with the software FLUENT. Daily measurement of the two parameters (algal biomass and chlorophyll-a concentration) was carried out during the experimental period to represent the algal growth rate. Meanwhile, the rates of photosynthetic oxygen evolution and chlorophyll fluorescence intensity were calculated to investigate the photosynthetic efficiency. The results indicated that the growth rate of Microcystis aeruginosa became higher in the turbulent environment than in the still water environment under the designed experimental conditions. The peak growth rate of Microcystis aeruginosa occurred when ε was 6.44 × 10−2 m2/s3, over which the rate declined, probably due to unfavorable impacts of strong turbulence. In comparison, the maximum rate of photosynthetic oxygen evolution occurred when ε was 0.19 m2/s3. Based on the findings of this study, an exponential function was proposed in order to incorporate the effect of flow turbulence into the existing algal growth models, which usually just consider the impacts of nutrient availability, illumination, and temperature.

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