scholarly journals Acute Toxicity Assay Using Mysid as an Alternative Test Organism in the Assessment of the Aqueous Fraction of Sediment

2021 ◽  
Author(s):  
Charrid Resgalla ◽  
Rafaela Silveira ◽  
Danielle Vieira
Keyword(s):  
Acute Toxicity ◽  
Sea Urchin ◽  
Sediment Quality ◽  
Sodium Thiosulfate ◽  
Test Organism ◽  
Complexing Agent ◽  
Aqueous Fraction ◽  
Test Organisms ◽  
Unionized Ammonia ◽  
Total Ammonia

Abstract The evaluation of sediment quality through biological testing of the aqueous fraction can be applied in dredging situations and is associated with a small number of confounding factors. The use of test organisms that are relatively resistant to contaminants is recommended when working with complex mixtures such as sediments. In this study, the sensitivity of the mysid Mysidopsis juniae to total ammonia and metals was investigated in acute toxicity laboratory tests and the results were compared to those obtained in the traditional test with sea urchin embryos and larvae. The ability of the toxicity identification and evaluation (TIE) technique, with the use of EDTA and sodium thiosulfate, to indicate the factors responsible for adverse effects was determined. The results indicate that mysids are almost 5 times more resistant than the sea urchin to unionized ammonia, more sensitive to Cd2+ and Ni2+ and more resistant to Zn2+ and Pb2+. With the TIE technique and with the use of EDTA as a complexing agent, a greater resolution was observed in the diagnosis of the presence of the metals Cd2+ and Ni2+, which could be applied to the aqueous fraction of the sediment.

Aluminum-dominated acute toxicity to the cladoceran Ceriodaphnia dubia in neutral waters downstream of an acid mine drainage discharge

2001 ◽  
Vol 58 (12) ◽  
pp. 2396-2404 ◽  
Author(s):  
David J Soucek ◽  
Donald S Cherry ◽  
Carl E Zipper
Keyword(s):  
Acid Mine Drainage ◽  
Acute Toxicity ◽  
Mine Drainage ◽  
Sediment Toxicity ◽  
Test Organism ◽  
Ceriodaphnia Dubia ◽  
Community Diversity ◽  
Neutral Ph ◽  
Acid Mine ◽  
Test Organisms

Acid mine drainage (AMD) is traditionally considered to impact aquatic ecosystems by acidification, metal precipitation smothering stream substrates, and sediment toxicity in association with trace metals. Using Ceriodaphnia dubia as a test organism, we conducted whole effluent toxicity (WET) tests with both field-collected and laboratory-synthesized AMD samples to investigate possible mechanisms of reduced benthic macroinvertebrate community diversity in neutral (pH > 7.0) waters downstream of an acidified tributary. Our results indicate that Al and Fe in transition from acidic waters to neutralizing receiving streams can cause acute toxicity to standard invertebrate test organisms at neutral pH. Aluminum, with an average LC50 (50% lethal concentration) of 2880 µg·L–1, was determined to be the cause of acute toxicity in the field for up to a mile downstream of the AMD-influenced tributary and was the likely cause of reduced community diversity at those sites. Although Fe singly may cause acute toxicity in this type of system, it appears to reduce the toxicity of combinations of other metals such as Al, Cu, and Zn.

scholarly journals Potential Use of the Benthic Foraminifers Bulimina denudata and Eggerelloides advenus in Marine Sediment Toxicity Testing

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 775
Author(s):  
Mary McGann
Keyword(s):  
Sea Urchin ◽  
Marine Sediment ◽  
Sediment Toxicity ◽  
Toxicity Testing ◽  
Fertilization Success ◽  
Toxicity Tests ◽  
Sediment Chemistry ◽  
Benthic Foraminifers ◽  
Sediment Toxicity Tests ◽  
Unionized Ammonia

The benthic foraminifers Bulimina denudata and Eggerelloides advenus are commonly abundant in offshore regions in the Pacific Ocean, especially in waste-discharge sites. The relationship between their abundance and standard macrofaunal sediment toxicity tests (amphipod survival and sea urchin fertilization) as well as sediment chemistry analyte measurements were determined for sediments collected in 1997 in Santa Monica Bay, California, USA, an area impacted by historical sewage input from the Hyperion Outfall primarily since the late 1950s. Very few surface samples proved to be contaminated based on either toxicity or chemistry tests and the abundance of B. denudata did not correlate with any of these. The abundance of E. advenus also did not correlate with toxicity, but positively correlated with total solids and negatively correlated with arsenic, beryllium, chromium, lead, mercury, nickel, zinc, iron, and TOC. In contrast, several downcore samples proved to be contaminated as indicated by both toxicity and chemistry data. The abundance of B.denudata positively correlated with amphipod survival and negatively correlated with arsenic, cadmium, unionized ammonia, and TOC; E. advenus negatively correlated with sea urchin fertilization success as well as beryllium, cadmium, and total PCBs. As B. denudata and E. advenus are tolerant of polluted sediments and their relative abundances appear to track those of macrofaunal toxicity tests, their use as cost- and time-effective marine sediment toxicity tests may have validity and should be further investigated.

Investigating the process of electrocoagulation in the removal of azo dye from synthetic textile effluents and the effects of acute toxicity on Daphnia magna test organisms

2022 ◽  
Vol 45 ◽  
pp. 102485
Author(s):  
Carlos Eduardo Lach ◽  
Camila Schwarz Pauli ◽  
Aline Scheller Coan ◽  
Edesio Luiz Simionatto ◽  
Luciano André Deitos Koslowski
Keyword(s):  
Acute Toxicity ◽  
Daphnia Magna ◽  
Azo Dye ◽  
Textile Effluents ◽  
Test Organisms

Bioaerosol Exposure Method for Package Integrity Testing†

1996 ◽  
Vol 59 (7) ◽  
pp. 768-771 ◽  
Author(s):  
SCOTT W. KELLER ◽  
JOSEPH E. MARCY ◽  
BARBARA A. BLAKISTONE ◽  
GEORGE H. LACY ◽  
CAMERON R. HACKNEY ◽  
...  
Keyword(s):  
Particle Size ◽  
Test Organism ◽  
Hole Diameter ◽  
Pseudomonas Fragi ◽  
Integrity Testing ◽  
Aerosol Exposure ◽  
Exposure Method ◽  
Test Organisms ◽  
Organism Growth ◽  
Bioaerosol Exposure

Test organism motility, concentration, aerosol exposure time, hole diameter and length were evaluated to determine their influence on microbial ingress into a flexible plastic pouch. Microtubes with 10- and 20-μm hole diameters and of 5- and 10-mm lengths were used as defects in 128 flexible pouches. A bioaerosol with a 2.68-μm mean particle size comprised of 102 or 106 CFU/ml source concentrations of motile or nonmotile Pseudomonas fragi TM 849 was introduced into a 119,911-cm3 chamber for exposures of 15 or 30 minutes. Six pouches showed test organism growth after a 72-h incubation period. Microbial ingress was significant (P < .05) for motile test organisms with source concentrations of 106 CFU/ml.

scholarly journals In vitro Assessment of Antiplasmodial Activity and Acute Oral Toxicity of Dissotis rotundifolia Extracts and Fractions on Plasmodium falciparum Strains

2020 ◽  
pp. 8-19
Author(s):  
Rock Djehoue ◽  
Rafiou Adamou ◽  
Abdou Madjid O. Amoussa ◽  
Adande A. Medjigbodo ◽  
Anatole Laleye ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Acute Toxicity ◽  
Ethanolic Extract ◽  
Antiplasmodial Activity ◽  
Oral Toxicity ◽  
Aqueous Fraction ◽  
Vector Borne Diseases ◽  
Natural Substances ◽  
Study Laboratory

Aim: Dissotis rotundifolia were selected after an ethnopharmacological survey conducted on plants used traditionally for malaria treatment in South Benin, with the aim of discovering new natural active extracts against malaria parasites. Place and Duration of Study: Laboratory of Biochemistry and Bioactive Natural Substances, University of Abomey-Calavi (Benin)/ Laboratory of Infectious Vector Borne Diseases, Regional Institute of Public Health (Benin)/ Laboratoire d’Histologie, de Cytogénétique et d’Embryologie, Faculté des Sciences de la Santé (Benin). The study was conduct from October 2018 to June 2019 in Benin. Methodology: The antiplasmodial activity of the plant extracts was evaluated using the parasite lactate dehydrogenase (pLDH) immunodetection assay. The extract with the best antiplasmodial activity were used on Wistar rats for acute toxicity. Results: Ethanolic extract of Dissotis rotundifolia showed promising activity (Isolate: IC50 = 22.58 ± 1.12 µg/mL; 3D7: IC50 = 6.81 ± 0.85 µg/mL) on Plasmodium falciparum compared to the aqueous extract (Isolate: IC50 > 100 µg/mL; 3D7: IC50> 100 µg/mL). The aqueous fraction of D. rotundifolia exhibit highly potent activity against P. falciparum strain (Isolate: IC50 > 100 µg/mL μg/mL; 3D7: IC50 = 4.05 ± 0.72 μg/mL). Haemolytic effect of actives extracts and fractions is less than 5%. Ethanolic extract of D. rotundifolia revealed no obvious acute toxicity in rat up to the highest dose administered (2000 mg/kg). Conclusion: This study justifies traditional uses of D. rotundifolia against malaria. A bioguided fractionation of these extracts would identify molecules responsible for their antiplasmodial activity. Moreover, these results could lead to the design of improved traditional medicines in the basis of this plant.

scholarly journals Evaluation of the Larvicidal Potential of the Leaf Extracts of Hyptis suaveolens Poit against Anopheles Mosquitoes

2018 ◽  
pp. 1-9
Author(s):  
Amaka, John I. ◽  
Attah, D. Daniel ◽  
Obisike, Victor U. ◽  
Benedict, Aboje G.
Keyword(s):  
Mosquito Control ◽  
Larval Instar ◽  
Test Organism ◽  
Phytochemical Screening ◽  
Leaf Extracts ◽  
Anopheles Mosquitoes ◽  
Lc50 Value ◽  
Hyptis Suaveolens ◽  
Test Organisms ◽  
Layer Chromatography

This study evaluated the larvicidal potential of the ethanolic and aqueous leaf extracts of Hyptis suaveolens Poit on the 4th larval instar of laboratory-reared Anopheles spp at varying concentrations of 0.1ml, 0.2ml, 0.3ml, 0.4ml and 0.5ml for specified periods of 24hrs, 48hrs and 72hrs. Qualitative phytochemical screening of the leaf extracts identified bioactive components like alkaloid, saponin, phenol, anthraquinone and flavonoid. The LC50 and LC90 values obtained indicate that the ethanolic leaf extracts of Hyptis suaveolens Poit had the greatest toxicity on the test organisms within 24hrs of exposure at median LC50 value of 0.485ml compared to the LC50 value of 0.625ml by its aqueous extract. The relative median potency estimates indicate that within 24 hrs, the ethanolic Hyptis suaveolens Poit was 0.161 times more potent on the test organism than aqueous Hyptis suaveolens Poit. The result of this research, therefore, underscores the efficacy of Hyptis suaveolens Poit as an eco-friendly alternative in Anopheles mosquito control. It is, therefore, recommended that quantitative phytochemical screening, application of column chromatography as well as thin layer chromatography be carried out on the extracts to isolate and purify toxic phytochemicals with larvicidal potentiality.

FUNGICIDAL ACTION AS AFFECTED BY INTERACTION OF NICKEL CHLORIDE, NABAM, ZINEB, AND ZINC SULPHATE

1961 ◽  
Vol 39 (3) ◽  
pp. 519-530 ◽  
Author(s):  
F. R. Forsyth ◽  
C. H. Unwin
Keyword(s):  
Zinc Sulphate ◽  
Early Blight ◽  
Fungicidal Activity ◽  
Test Organism ◽  
Brown Rot ◽  
Nickel Chloride ◽  
Fungicidal Action ◽  
Chloride Hexahydrate ◽  
Wettable Powder ◽  
Test Organisms

Protectant fungicidal action of mixtures of nabam, zineb, nickel chloride, and zinc sulphate was evaluated by means of a "microbeaker method" and the slide germination method, using as test organisms the fungi causing leaf rust of wheat, crown rust of oats, early blight of tomatoes, and brown rot of peaches. All of the fungicides tested were more effective against the two rusts than against the organisms causing early blight and brown rot. The relatively insoluble nickel ethylenebisdithiocarbamate was much less effective than the other chemicals tested. Ratios (w/w) of nickel chloride hexahydrate to zineb around unity and to nabam plus zinc sulphate from 2–10 to 1 showed an unfavorable effect on fungitoxic activity against urediospores of P. recondita. The ratio showing greatest antagonism varied, depending on the test organism used and whether or not tankmix or wettable powder zineb was used. The formation of nickel ethylenebisdithiocarbamate in the aqueous solution and its low fungicidal activity adequately explain the results obtained.

Single- and multi-species toxicity testing with nematodes.

2021 ◽  
pp. 298-322
Author(s):  
Sebastian Höss
Keyword(s):  
Caenorhabditis Elegans ◽  
Test Organism ◽  
Toxicity Testing ◽  
Single Species ◽  
Risk Assessments ◽  
Freshwater Sediments ◽  
Nematode Communities ◽  
Model Ecosystems ◽  
Test Organisms ◽  
Experimental Approaches

Abstract This chapter discusses the utility of nematodes in experimental ecotoxicology, and specifically in the study of freshwaters. Drawing on reports in which nematodes were used as test organisms in single-species tests as well as studies investigating nematode communities in model ecosystems (i.e. microcosms), the suitability of nematode-based experimental approaches in prospective and retrospective risk assessments of chemicals in freshwater sediments is examined. Several examples are presented of the use of Caenorhabditis elegans as a test organism in single-species bioassays, in order to demonstrate the versatility of this nematode for ecotoxicological investigations.

Some Principles of Microbiological Turbidimetric Assays of Antibiotics

1979 ◽  
Vol 62 (4) ◽  
pp. 951-956
Author(s):  
Robert A Rippere
Keyword(s):  
Linear Response ◽  
Test Organism ◽  
Limited Range ◽  
Liquid Media ◽  
Agar Diffusion ◽  
Assay Procedure ◽  
Test Organisms ◽  
Effective Use

Abstract Turbidimetric methods for determining the potency of antibiotics are inherently more accurate and more precise than are comparable agar diffusion procedures, but assays conducted in liquid media are subject to degradation from less than ideal conditions to a much greater extent than are diffusion methods. The relationships between test organisms, antibiotics, and assay concentrations are discussed. A valid assay procedure must produce a linear response with an adequate slope (–0.4 to –1.2) by the test organism to increasing concentrations of drug; such linear response normally occurs over a limited range of concentrations. Criteria used to select photometers that offer the greatest advantages to analytical microbiologists are described, with guidelines for the most effective use of the chosen instrument.

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