Effects of Ammonia and Density on Filtering of Commensal and Pathogenic <Emphasis Type="Italic">Escherichia coli</Emphasis> by the Cladoceran <Emphasis Type="Italic">Daphnia magna</Emphasis>

Grazing by cladocerans can reduce the survival of enteric bacteria associated with fecal pollution. This study examined the potential of Daphnia magna to filter commensal and pathogenic Escherichia coli of human origin. Grazing on commensal and pathogenic bacteria was comparable, but slightly greater at 20 compared to 15 and 25°C. Filtering activity was strongly dependent on D. magna and E. coli densities at environmentally relevant bacterial concentrations. Maximum feeding rates were >10⁷ cells h^?1 daphnid^?1, clearance rates were 1–6 mL h^?1 daphnid^?1, and filtering was independent of bacterial cell sizes between 0.7 and 1.8 µm. Filtering and ingestion of E. coli by D. magna was susceptible to acute inhibition by unionized ammonia with a 24 h EC50 of 0.18 mg L^?1 NH₃–N, and a LOEC of 0.09 mg L^?1 NH₃–N. The study indicated that biological and chemical constraints should be considered when applying Daphnia for attenuation of fecal pollution.     

Assessment of Cadmium Scavenging Potential of <Emphasis Type="Italic">Canna indica</Emphasis> L.

The aquatic plant, Canna indica L. (Indian shoot) of Cannaceae family was investigated to assess cadmium scavenging potential at 5, 10, 25, 50, 100 and 150 mg Cd L^?1 exposers. The results showed that Canna has considerable potential of cadmium accumulation, which was up to 58.69 and 10.13 mg Cd kg^?1 dry weight in root and shoot of Canna, respectively. The effects of different cadmium levels on biomass production of plant tissues were significantly (p?=?0.05) showed negative relation due to cadmium toxicity. The root concentration factor was higher than the bioconcentration factor which indicated the lower translocation factor of Canna. Considering the high root concentration factor, average bioconcentration factor, rapid growth and optimum adaptive properties up to 100 mg Cd L^?1 level, the Canna could be employed as an eco-friendly and efficient aquatic plant for cadmium scavenging. This study plays a potential role in remediation of cadmium contaminated wastewater.     

Uptake of Urea Nitrogen by <Emphasis Type="Italic">Oocystis borgei</Emphasis> in Prawn <Emphasis Type="Italic">(Litopenaeus vannamei)</Emphasis> Aquaculture Ponds

The goal of this study was to assess the rate of urea nitrogen uptake (ρ) by Oocystis borgei and the relationship between environmental factors and ρ. Light intensity, temperature, pH, salinity, and algal concentration, were used to construct an empirical model. The results showed that light intensity, algal concentration, pH and salinity had significant effects on ρ, and the optimal combination of environmental conditions for ρ was a temperature of 25°C, pH of 7.0, light intensity of 81 µmol m^?2 s^?1, salinity of 15‰, and algal concentration of 4.5?×?10⁸ cell L^?1–5.5?×?10⁸ cell L^?1. The model equation was ρ?=?2?×?10^?5?×?(A^0.363B^0.783C^0.045D^?0.503E)?+?0.0017, with a coefficient of determination (R²) of 0.83. No significant difference in variance was observed between the model-predicted values and the measured values (F?=?0.238, p?>?0.05), which demonstrated the high fitting degree of the simulation equation. This study provided valuable insight into the reduction of urea nitrogen levels in aquaculture water by O. borgei.     

Leaf Composition of American Bur-Reed (<Emphasis Type="Italic">Sparganium americanum</Emphasis> Nutt.) to Determine Pesticide Mitigation Capability

American bur-reed (Sparganium americanum Nutt.), a common aquatic plant in the middle and eastern United States and Canada, is often located in water-retaining drainage areas. The purpose of this study was to determine the leaf composition of S. americanum, paying attention to the cuticular waxes and the epidermis, and its ability to sorb pesticides. S. americanum leaves (n?=?100) were collected in both early (June) and late (August) summer. Transverse sections of S. americanum were stained and studied with brightfield and fluorescence microscopy to estimate the structural and chemical nature of the leaf tissues cross sections. Mean total lipid content in early summer leaf samples (1.47?±?0.83 mg mL^?1) was significantly greater (alpha 0.05) than late summer leaves (0.15?±?0.36 mg mL^?1). In vitro analysis of epidermal peel permeability exposed to atrazine and malathion determined little to no sorption by the plant. Therefore, the structure of S. americanum leaves suggest this species does not have the capacity of sorbing these pesticides from runoff water.     

Stress-Induced Transcriptional Changes and DNA Damage Associated with Bis(2-ethylhexyl) Adipate Exposure in Zebrafish (<Emphasis Type="Italic">Danio rerio</Emphasis>) Larvae

The present study evaluates potential toxic effects of bis(2-ethylhexyl) adipate (DEHA) plasticizer to larval (72 h post fertilization) zebrafish (Danio rerio) by analyzing changes in expression levels of stress-related genes (p53, rad51 and xrcc5) and assessing possible DNA damage of DEHA in larvae. The lethal concentration for 50% mortality (LC₅₀) in larval zebrafish exposed for 96 h to 0–200 mg L^?1 DEHA was 89.9?±?8.03 mg L^?1. A concentration-dependent increase in DNA strand breaks was detected in cells from larvae exposed for 96 h to DEHA. There were some significant differences in induction of stress-related genes in larvae exposed to DEHA relative to control.     

Acute Toxicity of Nitrite to Various Life Stages of the Amazon River Prawn,Macrobrachium amazonicum,Heller, 1862

This study determined the effects of nitrite on different life stages of the Amazon river prawn Macrobrachium amazonicum. Prawns of each life stage (postlarvae, juveniles and adults) were stocked in 24 experimental units (n?=?10 prawns), under a complete randomized design. Individuals were exposed to nitrite (0, 1, 2, 4, 8 and 16 mg L^?1). The median lethal concentration after 96 h (96 h LC₅₀) was calculated through the Weibull I. The mortality results showed that M. amazonicum is slightly less tolerant to nitrite than other species of Macrobrachium. The 96 h LC₅₀ for postlarvae, juveniles and adults of M. amazonicum were of 1.49, 2.36 and 2.34 mg nitrite/L, respectively. Nitrite intoxication risk quotient suggest moderated risk to low risk to the species. Usually in production systems nitrite values are lower than safe levels suggested in this study (0.1 mg L^?1 to postlarvae and 0.2 mg L^?1 nitrite to juvenile and adults), which makes our results appropriate for the production of this species.     

Concentrations of Arsenic and Boron in Water,Sediment and the Tissues of Fish in Emet Stream (Turkey)

In this study, the concentrations of arsenic and boron were determined in the water and the sediment, as well as in the muscle tissues of Squalius cephalus, Alburnoides bipunctatus, Barbus plebejus and Capoeta tinca from Emet Stream. The fish samples were caught in May 2011 and September 2012. The metal concentrations in the water samples were as follows: arsenic was 137.1–1002 µg L^?1, and boron was 2421–14490 µg L^?1. The metal concentrations in the sediment samples were as follows: arsenic was 14.51–3317.1 mg kg^?1, and boron was 14.22–1014.01 mg kg^?1. The mean tissue concentration of arsenic was lower than the TFC and WHO limits. Boron has been identified in fish tissues at concentrations between 0.26 and 2.96 mg kg^?1. The bioaccumulation in the muscle tissues of all fish species caught from Emet Stream did not exceed the limit values.     

Lead Tolerance and its Accumulation by a Tree Legume: <Emphasis Type="Italic">Dalbergia sissoo</Emphasis> DC

Dalbergia sissoo DC, a leguminous tropical timber tree has been investigated against the Pb toxicity; under the Pb-stress, plant’s morphology, biochemical parameters and genomic template stability (GTS) screened in vitro. At the optimum Pb tolerance level (150 mg L^?1), plant’s defense mechanism—superoxide dismutase, catalase, ascorbate peroxidases and proline could trigger to achieve optimum vegetative growth with minimum fluctuations of the GTS. Further, D. sissoo roots could accumulate 2399.8?±?16 mg kg^?1 Pb. Scanning electron microscopy and energy dispersive X-ray spectrometer analysis also revealed the deposition of Pb in root tissues. In a 1 year pot experiment with Pb-contaminated soil, the plants exhibited normal growth, and Pb accumulation significantly enhanced by the amalgamation of citric acid in the soil. Thus, the tree may prove as a potential candidate for Pb phytostabilization.     

Effects of 12-week supplementation of <Emphasis Type="Italic">Citrus bergamia</Emphasis> extracts-based formulation CitriCholess on cholesterol and body weight in older adults with dyslipidemia: a randomized,double-blind,placebo-controlled trial

Backgrounds

Recent experiments suggest that Citrus bergamia extracts could benefit people with dyslipidemia and obesity but this needs to be further validated.

Methods

A total of 98 people age-matched older adults (65 years) with elevated blood lipids were enrolled to receive 12-week supplementation of a Citrus bergamia extracts-based formulation (CitriCholess)(n?=?48) and placebo (n?=?50).

Results

No group differences were found in baseline bodyweight, body mass index (BMI), blood cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C) and glucose levels. CitriCholess supplementation resulted in lower levels than placebo in TG (1.83?±?0.92 vs. 1.95?±?1.34 mmol/L, P?=?0.612), TC (5.14?±?0.98 vs. 5.44?±?0.77 mmol/L, P?=?0.097), and LDL-C (3.13?±?0.74 vs. 3.43?±?0.62 mmol/L, P?=?0.032). Compared to placebo, CitriCholess also resulted in greater reductions in body weight (?0.604?±?0.939 vs. 0.06?±?0.74 kg, P?<?0.01), waist circumferences (?0.60?±?1.349 cm vs. -0.16?±?1.503 cm, P?<?0.01) and BMI (?0.207?±?0.357 vs. 0.025?±?0.274, P?<?0.01). Additionally, females had a significantly higher level of HDL-C than males. TC was significantly correlated with LDL-C, and to a less degree, with TG. TG was inversely correlated with HDL-C. Body weight and waist circumference were negatively correlated with HDL-C and positively correlated with glucose.

Conclusion

12-week supplementation of CitriCholess could benefit lipid metabolism and weight management in old adults with dyslipidemia.

     

Toxicity of CuO Nanoparticles to Structure and Metabolic Activity of Allium cepa Root Tips

Roots of Allium cepa were exposed to six CuO NPs suspensions (0, 5, 10, 20, 40, 80 mg L^?1) in this study. Results revealed that with the increase of CuO NPs concentration, the Cu content in roots increased significantly. Compared to control, onion roots treated with CuO NPs (except 5 mg L^?1 suspension) grew slowly after 24 h. The surface of the root cap and meristematic zone were obviously damaged. The apical meristem of roots treated by 10 mg L^?1 and above concentrations stopped division. The nucleus of meristematic cells deformed, and nucleoli number increased. The plasmolysis occurred, and the cell membrane and nuclear membrane fractured. With the increase of CuO NPs concentration, the MDA content increased, and the root activity decreased. When dealt with 80 mg L^?1 CuO NPs for 72 h, onion roots appeared to be corroded.     

Growth Study and Hydrocarbonoclastic Potential of Microorganisms Isolated from Aviation Fuel Spill Site in Ibeno,Nigeria

The growth study and hydrocarbonoclastic potential of microorganisms isolated from aviation fuel spill sites at Inua-eyet Ikot in Ibeno, Nigeria were examined using standard microbiological methods. The results of the analysis revealed that the viable plate count of microorganisms in the polluted soil ranged from 2.2 ± 0.04 × 10³ to 3.4 ± 0.14 × 10⁶ cfu/g for bacteria and 1.4 ± 0.5 × 10² to 2.3 ± 0.4 × 10⁴ cfu/g for fungi while count of biodegraders ranged from 1.2 ± 0.4 × 10³ to 2.1 ± 0.8 × 10⁵ cfu/g. A total of 11 microbial isolates comprising of Micrococcus, Klebsiella, Flavobacterium, Bacillus, Pseudomonas, Candida, Aspergillus, Cladosporium, Penicillium, Saccharomyces and Fusarium were characterized. The ability of the selected isolates to utilize the pollutant (aviation fuel) as their sole source of carbon and energy was examined and noticed to vary in growth profiles between the isolates. The results of their degradability after 28 days of incubation shows that species of Cladosporium, Pseudomonas, Candida, Bacillus, Micrococcus and Penicillium were the most efficient Aviation fuel degraders with percentage weight loss of 86.2, 78.4, 78, 56, 53 and 50.6 respectively. Flavobacterium, Saccharomyces and Aspergillus exhibited moderate growth with percentage weight loss of 48, 45.8 and 43.4 respectively while Klebsiella and Fusarium species showed minimal growth with percentage weight loss of 20 and 18.5 respectively. The results imply that the most efficient biodegraders like Cladosporium, Pseudomonas, Candida, Bacillus and Microoccus could tolerate and remove aviation fuel from the environment.     

Effects of 12-week supplementation of marine Omega-3 PUFA-based formulation Omega3Q10 in older adults with prehypertension and/or elevated blood cholesterol

Backgrounds

To study the effects of supplementation of a marine omega-3 poly-unsaturated fatty acids (n3-PUFA) formulation (Omega3Q10) in older adults with hypertension and/or hypercholesterolemia.

Methods

A total of 97 people were enrolled to receive 12-week supplementation of either Omega3Q10 (n?=?48) or soybean oil (n?=?49). Total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), and hypertension-related symptoms were determined before and after the supplementation.

Results

There were no baseline differences between the two groups. Omega3Q10 supplementation significantly reduced diastolic blood pressure (DBP) (from 81.6?±?5.3 mmHg to 79.3?±?5.2 mmHg, P?<?0.05). Blood concentrations of TC and LDL-C decreased significantly and blood HDL-C level increased significantly after 12 weeks of Omega3Q10 (5.5?±?0.7 vs. 5.3?±?0.5, P?<?0.05; 3.7?±?0.8 vs. 3.3?±?0.6, P?<?0.05; 1.2?±?0.6 vs. 1.3?±?0.5, P?<?0.05, respectively) and soybean oil supplementation (5.7?±?0.8 vs. 5.6?±?0.7, P?<?0.05; 3.6?±?0.7 vs. 3.4?±?0.8, P?<?0.05; 1.0?±?0.8 vs. 1.2?±?0.7, P?<?0.05, respectively) but no group differences were found. A significantly greater proportion of the people in the Omega3Q10 group became free from headache and palpitations & chest tightness symptoms after the 12-week supplementation compared to that of the soybean oil group (95.5% vs. 71.4%, P?<?0.01; 95.8 vs. 75.5%, P?<?0.01, respectively).

Conclusion

12-week supplementation of Fish oil-based PUFA appear to be more effective in improving DBP and hypertension-related symptoms than soybean oil in old adults with hypertension and hypercholesterolemia although both supplementation improved TC, LDL-C and HDL-C concentrations.

     

Effects of <Emphasis Type="Italic">Dracontomelon duperreanum</Emphasis> Leaf Litter on the Growth and Photosynthesis of <Emphasis Type="Italic">Microcystis aeruginosa</Emphasis>

This study investigated the use of Dracontomelon duperreanum leaf litter extract (DDLLE) in inhibiting the growth and photosynthesis of the algae Microcystis aeruginosa. The goal of the study was to evaluate a potential solution for cyanobacterial bloom prevention. M. aeruginosa was exposed to extract concentrations from 0.4 to 2.0 g L^?1. Chlorophyll-a (Chl-a) content and photosynthesis levels were assessed using pulse amplitude modulated fluorimetry phytoplankton analyzer. Results suggested that the extract could efficiently suppress M. aeruginosa growth. The content of Chl-a was only 19.0 µg L^?1 and achieved 96.0% inhibition rate when exposed to 2.0 g L^?1 on day 15. Growth rate in response to different extract concentrations were consistent with changes in the photosynthesis efficiency (alpha), maximal relative electron transport rate and maximal photochemical efficiency of photosystem II (F _v /F _m ). Furthermore, several kinds of volatile chemicals and their concentrations in DDLLE had been identified by GC–MS, which of them play major role to suppress the growth of M. aeruginosa should be further studied.     

Effect of Soil Type,Moisture and Temperature on the Dissipation of Penoxsulam in Soil Under Laboratory Conditions

A study was performed for phyto-genotoxic assay of chromium (Cr) and arsenic (As) through Allium cepa. Various concentrations (0, 1, 3, 6 and 12 mg L^?1) of Cr and As for 48 and 168 h time points exposed to A. cepa. The phytotoxic effects of metal(loid) were evident through inhibited root length and root protein. Metal(loid) toxicity also lead to genotoxic effects, which included depression of mitotic index and increased frequency of chromosomes aberrations like break, fragments, c-metaphase, multipolar arrangements etc. Genotoxic endpoint as progressive frequency of micronuclei in interphase of root meristem cells in treated plants was also observed. This genotoxic endpoint revealed carcinogenic nature of both aforementioned metal(loid). Along with inhibition in root length and protein content, depression in mitotic index as well as stimulation of various abnormality in mitotic cell division indicated that both metal(loid) are hazardous in nature and causing harmful effect on the environment.     

Growth Recovery of <Emphasis Type="Italic">Lemna gibba</Emphasis> and <Emphasis Type="Italic">Lemna minor</Emphasis> Following a 7-Day Exposure to the Herbicide Diuron

In agricultural catchments, aquatic ecosystems can experience a pulse exposure to pesticides. Following such exposure, non-target organisms that are not extirpated may recover. This paper investigates the potential of two duckweed species (Lemna minor and Lemna gibba) to recover from a 7-day exposure to different concentrations (0.4–208 µg L^?1) of the herbicide diuron. There was significant inhibition in the growth and biomass after the initial 7-day exposure (e.g. frond number EC₅₀ = 59.2 and 52.2 µg L^?1 for L. minor and L. gibba, respectively). Following transfer to clean media, recovery (the highest concentration yielding no significant difference in the effect endpoint from the control) was observed for all effects endpoints at concentrations ranging 60–111 µg L^?1 for L. minor and 60–208 µg L^?1 for L. gibba. These results suggest that recovery is possible for primary producers at environmentally relevant concentrations considered significant in ecological risk assessment.     

Toxicity of Nickel on the Selected Species of Marine Diatoms and Copepods

Toxicity values for nickel on marine diatoms and copepods were derived based on bioassay tests. The 96 h IC₅₀ of nickel on diatoms, Odontella mobiliensis and Coscinodiscus centralis were 0.31?±?0.01 and 0.62?±?0.02 mg/L and LC₅₀ values on copepods, Oithona similis and Acartia danae were 2.78?±?0.14 and 2.34?±?0.32 mg/L, respectively. The species mean chronic values of nickel were 0.016, 0.17, 0.57 and 0.42 mg/L for O. mobiliensis, C. centralis, O. similis and A. danae, respectively. A hazardous concentration was derived and evaluated using the species sensitivity distribution (SSD) method. SSD indicated that 13 µg Ni/L is the maximum allowable concentration for protection of 95% plankton species in coastal and marine ecosystem of India. Diatoms are more sensitive to nickel than copepods by almost an order of magnitude. The toxicity values derived in the present study may be useful to calculate ambient water quality criteria/standard for nickel.     

Effect of 8-weeks prebiotics/probiotics supplementation on alcohol metabolism and blood biomarkers of healthy adults: a pilot study

Purpose

Modulating gut bacteria via regular prebiotics/probiotics consumption may improve the metabolism of acute alcohol ingestion. This study investigated the impact of 8-weeks prebiotics/probiotics supplementation on microbiome changes and responses to acute alcohol consumption.

Methods

38 participants (21 females, 23.6?±?3.4 kg m^?2, mean?±?SD) attended the laboratory on two occasions separated by an 8-week intervention period. On each of these visits, a dose of alcohol (0.40?±?0.04 g kg^?1, Vodka?+?Soda-Water) was consumed over 10 min. Breath alcohol concentration was sampled over 5 h and alcohol pharmacokinetics was analysed using WinNonlin non-compartmental modelling (C_max, t_max, AUC_last). For the intervention, participants were randomised to receive Placebo?+?Placebo (PLA), Placebo?+?Prebiotics (PRE), Probiotics?+?Placebo (PRO), or Probiotics?+?Prebiotics (SYN) in a double-blinded manner. Probiotics were a commercially available source of Lactobacillus acidophilus (NCFM^®) and Bifidobacterium lactis (Bi-07). Prebiotics were a commercially available source of Larch Gum (from Larix occidentalis). Placebo was microcrystalline cellulose. Each visit, participants provided a stool sample, which was analysed to determine the presence of L. acidophilus and B. lactis. Differences between trials were analysed using paired samples t tests.

Results

Increased counts for at least one bacterial strain (L. acidophilus or B. lactis) were observed for all participants on SYN (n?=?10) and PRO (n?=?10) trials. No difference in C_max or t_max was observed between trials when analysed by treatment condition or microbiome outcome. A significant decrease in AUC_last was observed between trials for PLA (p?=?0.039) and PRE (p?=?0.030) treatments, and when increases in at least one bacterial strain (p?=?0.003) and no microbiome changes (p?=?0.016) were observed.

Conclusion

Consumption of probiotics appears to alter faecal counts of supplemental bacterial strains in otherwise healthy individuals. However, translation to any possible beneficial impact on alcohol metabolism remains to be elucidated.

     

Effects of Water pH on Life History Parameters of a New Bosminid Cladocera: <Emphasis Type="Italic">Bosmina (Bosmina) Tripurae</Emphasis> (Korinek,Saha and Bhattachaya, 1999) in Laboratory Condition

The effects of water pH on life history parameters of Bosmina tripurae have been studied to determine the most suitable water pH desired for the maximum growth and development of this newly discovered cladoceran species. The study was carried out under the laboratory condition at 20?±?2°C. Five pH ranges 5.0?±?0.2, 6.0?±?0.2, 7.0?±?0.2, 8.0?±?0.2 and 9.0?±?0.2 with six replicates for each pH consisting of one animal in each Petri dish (80?×?15 mm) were used for the study. 20 mL of respective test medium was maintained with Chlorella sp. (2?×?10⁴?±?0.03 cells mL^?1) in each Petri dish throughout the experiment. Thirty (30) animals were observed daily to investigate different life history parameters like total life span, age at maturity, number of eggs, neonates and egg batches etc. at different condition. From the study it was found that acidic water (pH 5?±?0.2) is more suitable for the culture of Bosmina tripurae in laboratory condition.     

Heavy Metal Concentration in Largehead Hairtail (<Emphasis Type="Italic">Trichiurus lepturus</Emphasis> Linneaus, 1758) and Savalai Hairtail (<Emphasis Type="Italic">Lepturacanthus savala</Emphasis> (Cuvier, 1829)) Obtained from Karachi Fish Harbour,Pakistan

In this study, muscle samples gathered from Largehead hairtail (Trichiurus lepturus Linneaus, 1758) and Savali hairtail [Lepturacanthus savala (Cuvier, 1829)] from the Karachi Fish Harbour, Pakistan were analyzed to determine heavy metal concentrations (iron [Fe], zinc [Zn], copper [Cu], manganese [Mn], lead [Pb] and cadmium [Cd]) between January and December 2016. All samples were analyzed using the AAnalyst 700 Flame Atomic Absorption Spectrophotometer. It was observed that the average measured level of Fe, Zn, Cu, Mn, Pb and Cd in muscle were 77.72?±?47.84 µg/g, 20.34?±?8.49 µg/g, 2.23?±?1.16 µg/g, 0.57?±?0.36 µg/g, 0.20?±?0.16 µg/g and 0.42?±?0.19 µg/g for T. lepturus, respectively. Besides, the average level of the same metal concentrations in muscle for L. savala were 85.11?±?57.64 µg/g, 16.63?±?9.25 µg/g, 2.53?±?1.90 µg/g, 0.47?±?0.27 µg/g, 0.23?±?0.18 µg/g and 0.47?±?0.20 µg/g, respectively. The correlation between size groups and metal accumulation in muscle tissues were investigated for both fish. In terms of public risk assessment, the provisional tolerable weekly intake’s of various heavy metals were compared with the consumption of both fish. As a result of the analysis, Fe, Zn, Cu, Mn, Pb and Cd accumulations in muscle tissues of T. lepturus and L. savala collected from Karachi Fish Harbour Pakistan did not exceed limit values.     

Evaluation of the Removal of Potassium Cyanide and its Toxicity in Green Algae (<Emphasis Type="Italic">Chlorella vulgaris</Emphasis>)

To evaluate the removal of potassium cyanide (KCN) and its toxicity in algae, an initial comprehensive analysis was performed with Chlorella vulgaris. The algae showed potential removal capability for KCN, with the maximal removal rate of 61%. Moreover, effects of KCN on growth, cellular morphology and antioxidant defense system of C. vulgaris were evaluated. Cell number and chlorophyll a content decreased in most cases, with the maximal inhibition rates of 48% and 99%, respectively. The 100 mg L^??1 KCN seriously damaged the algal cell membrane. Additionally, activity of superoxide dismutase (SOD) was promoted by KCN exposure among 0.1–50 mg L^??1 and inhibited by 100 mg L^??1 KCN, while the malondialdehyde (MDA) content gradually decreased in C. vulgaris with increasing exposure concentration compared to the control. The present study reveals that C. vulgaris is useful in bio-treatment of cyanide-contaminated aquatic ecosystem, except in high concentrations which would cause overwhelming effects.