The objective of this research was to isolate a dichlorvos (2,2-dichlorovinyl dimethyl phosphate)-degrading strain of Ochrobactrum sp., and determine its effectiveness in remediation of a dichlorvos-contaminated soil....The objective of this research was to isolate a dichlorvos (2,2-dichlorovinyl dimethyl phosphate)-degrading strain of Ochrobactrum sp., and determine its effectiveness in remediation of a dichlorvos-contaminated soil. A dichlorvos-degrading bacterium (strain DDV-1) was successfully isolated and identified as an Ochrobactrumsp. based on its 16S rDNA sequence analysis. Strain DDV-1 was able to utilize dichlorvos as a sole carbon source, and the optimal pH and temperature for its cell growth and degradation were 7.0 and 30 ℃, respectively. Also, the growth and degradation of strain DDV-1 showed the same response to dissolved oxygen. In addition, the soil degradation test indicated that in soil spiked with 100 mg L-1 or 500 mg L-1 dichlorvos and inoculated with 0.5% or 1.0% (v/v) strain DDV-1, complete degradation of dichlorvos could be achieved in 24 h. The present study showed that strain DDV-1 was a fast dichlorvos-degrading bacterium in soil. However, further research will be needed to clarify the degradation pathway and the properties of the key enzymes involved in its biodegradation.展开更多
In this study, we determined the cytotoxicity and genotoxicity of carbamate insecticide carbaryl to flounder gill （FG） cells and its teratogenicity to zebrafish embryos. The cytotoxicity of carbaryl to FG cells was ...In this study, we determined the cytotoxicity and genotoxicity of carbamate insecticide carbaryl to flounder gill （FG） cells and its teratogenicity to zebrafish embryos. The cytotoxicity of carbaryl to FG cells was determined with methods including MTT and neutral red uptaking （NRU）, lactate dehydrogenase （LDH） releasing and Hoechst 33342 and propidiurn idodide （PI） double staining. Moderate cytotoxicity in a concentration-dependent manner was observed. The 24h-IC50 value of 53.48 ± 1.21, 59.13 ± 1.19 and 46.21 ± 1.24 mgL 1 carbaryl was obtained through MTT, NRU and LDH assays, respectively. Double fluorescence staining dem- onstrated that carbaryl induced the death of FG cells mainly through necrosis. There was no significant genotoxicity found in the FG cells exposed to the highest testing concentration of carbaryl （20mgL-1, P〉0.05） as was demonstrated by Comet assay. Zebrafish embryos exposed to carbaryl at concentrations 〉10 mg L-1 displayed moderate toxic effects on the survival, spontaneous movement, hatching, heart rates of the embryos and their development, which were evidenced by yolk and pericardial sac edemas, body length reduction and tail flexure in time- and concentration-dependent manners at specific stages. The 24h-, 48h- and 96h-LC50 values of carbaryl to zebra fish embryos were 41.80 ± 1.10, 17.80 ± 1.04 and 14.46 ± 1.05 mg L-1, respectively. These results suggested that car- baryl is moderately toxic to FG ceils cultured in vitro and zebrafish embryos, and the FG cells were similar to zebrafish embryos in their sensitivity to carbaryl as 24h-IC50 and LC50 indicated.展开更多
The studies have been carried out in laboratory on the effect of dyeing,electroplating, pesticide effluents and their intermixture on embryos of lefteye flounder (Paralichthys olivaceus ). The main toxic substances in...The studies have been carried out in laboratory on the effect of dyeing,electroplating, pesticide effluents and their intermixture on embryos of lefteye flounder (Paralichthys olivaceus ). The main toxic substances in dying effluent are aniline ( 20 mg/L ) andphenol ( 24 mg/L ). The main toxic substances in electroplating effluent are Zn ( 1 970 mg/L ). Cu (9 mg/L ) and Pb ( 7.5 mg/L ). The main toxic substances in pesticide effluent are monocrotophos andphosphite. The test results indicate that the lowest concentrations of dyeing, electroplating,pesticide effluents and their intermixture, having significant effect on the hatch rate anddevelopment of P. olivaceus embryos, are 0.5 %, 0.15 %, 0.25 % and 0.25 %, respectively; and theincipient LC_(50) of dyeing, electroplating, pesticide effluents and their intermixture are 3.38 % (2.29 %～3.87 % ), 0.81 % ( 0.71 % ～0. 92 % ). 1.57 % ( 1.37 %～1.82 % ) and 1.48 % ( 1.24 %～1.76% ). Based on the incipient LG_(50) values, the toxicity sequence of the three industrial effluentsis in the order of electroplating effluent > pesticide effluent > dyeing effluent.展开更多
Endosulfan, an organochlorine pesticide, is highly toxic and effective at controlling pests in agriculture, horticulture, and public health programs. In this study, static bioassays were used to evaluate the toxicity ...Endosulfan, an organochlorine pesticide, is highly toxic and effective at controlling pests in agriculture, horticulture, and public health programs. In this study, static bioassays were used to evaluate the toxicity of endosulfan to freshwater prawns( Macrobrachium rosenbergii) of various lengths(1.5±0.03,4±0.08, and 7±0.06 cm). Additionally, the activities of peroxidase(POD), acid phosphatase(ACP),alkaline phosphatase, acetylcholinesterase(AChE), and Na + /K +-ATPase were analyzed to refl ect the effects of endosulfan exposure. The 96 h LC 50 of endosulfan for prawns 1.5, 4, and 7 cm long were 1.86, 4.53,and 6.09μg/L, respectively, improved tolerance to endosulfan with growth. The POD activities of test organisms exposed to low concentrations of endosulfan were inhibited, indicating the presence of oxygen damaged tissue. Moreover, a notable decrease in AChE activity was observed due to overstimulation of neurotransmission, which might result in abnormal behavior. The effect caused by endosulfan on phosphatase production in the hepatopancreas of prawns 1.5, 4, and 7 cm long was different because the ability of nonspecifi c immune regulation increased with growth. The 96 h LC 50 values obtained in this study could be used in the formulation of water-quality criteria in China. Moreover, the changes in enzymes activities of M. rosenbergii under stress of endosulfan could be applied in the establishment of early warning indicators for bio-safety.展开更多
Sumithion is widely used to control brittle in paddy fields and tiger bug in fish larval rearing ponds. The objective of this study was to elucidate the toxic effects of sumithion on larval stages of stinging catfish ...Sumithion is widely used to control brittle in paddy fields and tiger bug in fish larval rearing ponds. The objective of this study was to elucidate the toxic effects of sumithion on larval stages of stinging catfish Heteropneustes fossilis. Larvae were exposed to two concentrations(150 and 250 μg/L) of sumithion with one control in three replicates of each. Larvae samples were collected at 20- and 24-h intervals followed by observation under a digital microscope. Exposures of stinging catfish larvae to sumithion produced deformities including irregular head shape, lordosis, yolk sac edema, body arcuation, tissue ulceration, etc. The mortality rates of larvae were significantly increased in response to increase in sumithion concentrations. Furthermore, around 30% of the total adult stinging catfish reared in sumithiontreated aquaculture ponds were found to be deformed permanently. These findings highlight that exposure of stinging catfish to sumithion at the critical and sensitive stages in their life cycle may significantly reduce the number of returning adults. Therefore, the use of sumithion for crop protection needs to be considered carefully and alternatives to sumithion should to be developed for controlling aquatic insects in aqua-ponds during larval rearing.展开更多
Bemisia tabaci is one of serious insect pests attacking vegetables and has been difficult to control using conventional insecticides. In the past 10 years, new insecticides have been introduced that provide a diversit...Bemisia tabaci is one of serious insect pests attacking vegetables and has been difficult to control using conventional insecticides. In the past 10 years, new insecticides have been introduced that provide a diversity of novel modes of action and routes of activity to effectively control whitefly. Consequently, intensive used of insecticides in vegetable cultivation has resulted in reduced susceptibility and develops resistance in agriculture industry. In controlling B. tabaci population, insecticides are the common method used by farmers. This study aimed to determine the most effective insecticide against B tabaci by using LC5o value. This study was conducted at the Crop Protection Laboratory, Faculty of Applied Science, Universiti Teknologi MARA Malaysia with the controlled room temperature of 24.33 ± 0.14℃ with dark and light ratio of 1：1 （12 hours： 12 hours） is an ideal condition for rearing the insect. The hypothesis of the study is to test if insecticides can control the nymph of whitefly. A total of 50 two-day-old nymphs were treated with insecticides using leaf-dip bioassay procedure. This experiment was replicated three times. The survival rates of the nymphs were analyzed using analysis of variance （ANOVA）. Data on toxicity was analyzed by a special Probit Programme-Single Line Analysis based on Finney （1971）. There was a significant difference （df = 8, F = 85.84, P = 0.000） in survival rate of nymph ofB. tabaci to eight insecticides tested. Among the insecticides tested, dimethoate, chlorpyrifos ＋ cypermethrin and diafenthiuron showed significantly higher survival rate of nymph compared to other treatments. When LC50 values were compared for diafenthiuron which is less potent （LCs0 ---- 2.44）, abamectin was found to be 3.44 times more potent than diafenthiuron, followed by esfenvalerate,acetamiprid, profenofos, chlorpyrifos ＋ cypermethrin and dimethoate, and the least potent was deltamethrin. The toxicity of eight insecticides tested against nymphs was in the following orders： abamectin = esfenvalerate = acetamiprid = profenofos =- chlorpyrifos ＋ cypermethrin ≥ dimethoate ≥ deltamethrin 〉 diafenthiuron respectively. This study implies that a proper application of the insecticide is a key component to a successful control programme of insect oests.展开更多
基金Project supported by the National High Technology Research and Development Program of China (863 Program)(Nos.2001AA214121, 2002AA246081 and 2003AA241150)the National Key Technologies Research and Development Program of China during the 9th Five-Year Plan Period (No. 2002BA516A01)the National Natural Science Foundation of China (No. 30400013).
文摘The objective of this research was to isolate a dichlorvos (2,2-dichlorovinyl dimethyl phosphate)-degrading strain of Ochrobactrum sp., and determine its effectiveness in remediation of a dichlorvos-contaminated soil. A dichlorvos-degrading bacterium (strain DDV-1) was successfully isolated and identified as an Ochrobactrumsp. based on its 16S rDNA sequence analysis. Strain DDV-1 was able to utilize dichlorvos as a sole carbon source, and the optimal pH and temperature for its cell growth and degradation were 7.0 and 30 ℃, respectively. Also, the growth and degradation of strain DDV-1 showed the same response to dissolved oxygen. In addition, the soil degradation test indicated that in soil spiked with 100 mg L-1 or 500 mg L-1 dichlorvos and inoculated with 0.5% or 1.0% (v/v) strain DDV-1, complete degradation of dichlorvos could be achieved in 24 h. The present study showed that strain DDV-1 was a fast dichlorvos-degrading bacterium in soil. However, further research will be needed to clarify the degradation pathway and the properties of the key enzymes involved in its biodegradation.
基金supported by the grants from National High-tech R&D Program of China (863 Program, Grant No. 2012AA 10A402)National Natural Science Foundation of China (Grant Nos. 31172391 and 31472274)+1 种基金Key Laboratory Open Foundation of Marine Bioactive Substances and Modern Analytical Technology, State Oceanic Administration (No. MBSMAT-2011-01)Fundamental Research Funds for the Central Universities of China (Grant No. 201122005)
文摘In this study, we determined the cytotoxicity and genotoxicity of carbamate insecticide carbaryl to flounder gill （FG） cells and its teratogenicity to zebrafish embryos. The cytotoxicity of carbaryl to FG cells was determined with methods including MTT and neutral red uptaking （NRU）, lactate dehydrogenase （LDH） releasing and Hoechst 33342 and propidiurn idodide （PI） double staining. Moderate cytotoxicity in a concentration-dependent manner was observed. The 24h-IC50 value of 53.48 ± 1.21, 59.13 ± 1.19 and 46.21 ± 1.24 mgL 1 carbaryl was obtained through MTT, NRU and LDH assays, respectively. Double fluorescence staining dem- onstrated that carbaryl induced the death of FG cells mainly through necrosis. There was no significant genotoxicity found in the FG cells exposed to the highest testing concentration of carbaryl （20mgL-1, P〉0.05） as was demonstrated by Comet assay. Zebrafish embryos exposed to carbaryl at concentrations 〉10 mg L-1 displayed moderate toxic effects on the survival, spontaneous movement, hatching, heart rates of the embryos and their development, which were evidenced by yolk and pericardial sac edemas, body length reduction and tail flexure in time- and concentration-dependent manners at specific stages. The 24h-, 48h- and 96h-LC50 values of carbaryl to zebra fish embryos were 41.80 ± 1.10, 17.80 ± 1.04 and 14.46 ± 1.05 mg L-1, respectively. These results suggested that car- baryl is moderately toxic to FG ceils cultured in vitro and zebrafish embryos, and the FG cells were similar to zebrafish embryos in their sensitivity to carbaryl as 24h-IC50 and LC50 indicated.
文摘The studies have been carried out in laboratory on the effect of dyeing,electroplating, pesticide effluents and their intermixture on embryos of lefteye flounder (Paralichthys olivaceus ). The main toxic substances in dying effluent are aniline ( 20 mg/L ) andphenol ( 24 mg/L ). The main toxic substances in electroplating effluent are Zn ( 1 970 mg/L ). Cu (9 mg/L ) and Pb ( 7.5 mg/L ). The main toxic substances in pesticide effluent are monocrotophos andphosphite. The test results indicate that the lowest concentrations of dyeing, electroplating,pesticide effluents and their intermixture, having significant effect on the hatch rate anddevelopment of P. olivaceus embryos, are 0.5 %, 0.15 %, 0.25 % and 0.25 %, respectively; and theincipient LC_(50) of dyeing, electroplating, pesticide effluents and their intermixture are 3.38 % (2.29 %～3.87 % ), 0.81 % ( 0.71 % ～0. 92 % ). 1.57 % ( 1.37 %～1.82 % ) and 1.48 % ( 1.24 %～1.76% ). Based on the incipient LG_(50) values, the toxicity sequence of the three industrial effluentsis in the order of electroplating effluent > pesticide effluent > dyeing effluent.
基金Supported by Key Project of Shanghai Municipal Science and Technology Commission,China(No.11391901400)
文摘Endosulfan, an organochlorine pesticide, is highly toxic and effective at controlling pests in agriculture, horticulture, and public health programs. In this study, static bioassays were used to evaluate the toxicity of endosulfan to freshwater prawns( Macrobrachium rosenbergii) of various lengths(1.5±0.03,4±0.08, and 7±0.06 cm). Additionally, the activities of peroxidase(POD), acid phosphatase(ACP),alkaline phosphatase, acetylcholinesterase(AChE), and Na + /K +-ATPase were analyzed to refl ect the effects of endosulfan exposure. The 96 h LC 50 of endosulfan for prawns 1.5, 4, and 7 cm long were 1.86, 4.53,and 6.09μg/L, respectively, improved tolerance to endosulfan with growth. The POD activities of test organisms exposed to low concentrations of endosulfan were inhibited, indicating the presence of oxygen damaged tissue. Moreover, a notable decrease in AChE activity was observed due to overstimulation of neurotransmission, which might result in abnormal behavior. The effect caused by endosulfan on phosphatase production in the hepatopancreas of prawns 1.5, 4, and 7 cm long was different because the ability of nonspecifi c immune regulation increased with growth. The 96 h LC 50 values obtained in this study could be used in the formulation of water-quality criteria in China. Moreover, the changes in enzymes activities of M. rosenbergii under stress of endosulfan could be applied in the establishment of early warning indicators for bio-safety.
文摘Sumithion is widely used to control brittle in paddy fields and tiger bug in fish larval rearing ponds. The objective of this study was to elucidate the toxic effects of sumithion on larval stages of stinging catfish Heteropneustes fossilis. Larvae were exposed to two concentrations(150 and 250 μg/L) of sumithion with one control in three replicates of each. Larvae samples were collected at 20- and 24-h intervals followed by observation under a digital microscope. Exposures of stinging catfish larvae to sumithion produced deformities including irregular head shape, lordosis, yolk sac edema, body arcuation, tissue ulceration, etc. The mortality rates of larvae were significantly increased in response to increase in sumithion concentrations. Furthermore, around 30% of the total adult stinging catfish reared in sumithiontreated aquaculture ponds were found to be deformed permanently. These findings highlight that exposure of stinging catfish to sumithion at the critical and sensitive stages in their life cycle may significantly reduce the number of returning adults. Therefore, the use of sumithion for crop protection needs to be considered carefully and alternatives to sumithion should to be developed for controlling aquatic insects in aqua-ponds during larval rearing.
文摘Bemisia tabaci is one of serious insect pests attacking vegetables and has been difficult to control using conventional insecticides. In the past 10 years, new insecticides have been introduced that provide a diversity of novel modes of action and routes of activity to effectively control whitefly. Consequently, intensive used of insecticides in vegetable cultivation has resulted in reduced susceptibility and develops resistance in agriculture industry. In controlling B. tabaci population, insecticides are the common method used by farmers. This study aimed to determine the most effective insecticide against B tabaci by using LC5o value. This study was conducted at the Crop Protection Laboratory, Faculty of Applied Science, Universiti Teknologi MARA Malaysia with the controlled room temperature of 24.33 ± 0.14℃ with dark and light ratio of 1：1 （12 hours： 12 hours） is an ideal condition for rearing the insect. The hypothesis of the study is to test if insecticides can control the nymph of whitefly. A total of 50 two-day-old nymphs were treated with insecticides using leaf-dip bioassay procedure. This experiment was replicated three times. The survival rates of the nymphs were analyzed using analysis of variance （ANOVA）. Data on toxicity was analyzed by a special Probit Programme-Single Line Analysis based on Finney （1971）. There was a significant difference （df = 8, F = 85.84, P = 0.000） in survival rate of nymph ofB. tabaci to eight insecticides tested. Among the insecticides tested, dimethoate, chlorpyrifos ＋ cypermethrin and diafenthiuron showed significantly higher survival rate of nymph compared to other treatments. When LC50 values were compared for diafenthiuron which is less potent （LCs0 ---- 2.44）, abamectin was found to be 3.44 times more potent than diafenthiuron, followed by esfenvalerate,acetamiprid, profenofos, chlorpyrifos ＋ cypermethrin and dimethoate, and the least potent was deltamethrin. The toxicity of eight insecticides tested against nymphs was in the following orders： abamectin = esfenvalerate = acetamiprid = profenofos =- chlorpyrifos ＋ cypermethrin ≥ dimethoate ≥ deltamethrin 〉 diafenthiuron respectively. This study implies that a proper application of the insecticide is a key component to a successful control programme of insect oests.
