Methomyl, an extremely toxic pesticide, is widely used in agriculture. A strain named mdw-1 capable of degrading methomyl rapidly was successfully isolated from activated sludge in this study. It could utilize methomy...Methomyl, an extremely toxic pesticide, is widely used in agriculture. A strain named mdw-1 capable of degrading methomyl rapidly was successfully isolated from activated sludge in this study. It could utilize methomyl as the sole carbon or nitrogen source. The optimal temperature and medium pH for its growth and methomyl biodegradation were 30℃ and 7.0, respectively. It was identified as a Paracoccus sp. according to its morphological features, physiological and biochemical characteristics, and phylogenetic analysis based on the sequence of 16S rDNA. Gas chromatography-mass spectrometry （GC-MS） analysis showed that methomyl could be completely transformed to S-methyl-N-hydroxythioacetamidate in 10 h of incubation with the isolate mdw-1.展开更多
A solid phase extraction procedure of methomyl and thiodicarb from environmental water was presented. This method utilizes a 40—60 mesh activated carbon cartridge and high performance liquid chromatography (HPLC). Th...A solid phase extraction procedure of methomyl and thiodicarb from environmental water was presented. This method utilizes a 40—60 mesh activated carbon cartridge and high performance liquid chromatography (HPLC). The 40—60 mesh activated carbon works faster and yield higher adsorption efficiency. Detection limits of methomyl and thiodicarb in environmental water are 0 1 μg/L and 0 2 μg/L, respectively. Average recoveries of fortified methomyl and thiodicarb in water are in the range of 90 7%—98 8% and 88 9%—103 6%, respectively. The relative standard deviations are lower than 7%. This method is simple, rapid, accurate and precise.展开更多
Modeling experimental design was used to study the main effects and the interaction effects between operational parameters in the photocatalytic degradation of pesticide methomyl. The important parameters which affect...Modeling experimental design was used to study the main effects and the interaction effects between operational parameters in the photocatalytic degradation of pesticide methomyl. The important parameters which affect the removal efficiency of methomyl such as concentration of Fe(NO3)3, concentration of H2O2, initial concentration of the pesticide and pH. The parameters were coded as x1, x2, x3 and x4, consecutively, and were investigated at two levels (–1 and +1). The effects of individual variables and their interaction effects for dependent variables, namely, photocatalytic degradation efficiency (%) were determined. From the statistical analysis, the most effective parameters in the photocatalytic degradation efficiency were initial concentrations of the methomyl and Fe(NO3)3. The interaction between initial concentration of the pesticide and Fe(NO3)3 was the most influencing interaction. The optimum conditions that were obtained for the photocatalytic degradation of methomyl were: minimum quantity of contaminant: 6 × 10–5 mol.L–1, maximum quantity of Fe(NO3)3: 5 × 10–4 mol.L-1, initial pH of the solution: 3 and maximum quantity H2O2: 10–2 mol.L–1.展开更多
[Objectives]This study was conducted to construct forward and reserve libraries of suppression subtractive hybridization (SSH) in the testis of male tilapia under the stress of methomyl by using SSH technology.[Method...[Objectives]This study was conducted to construct forward and reserve libraries of suppression subtractive hybridization (SSH) in the testis of male tilapia under the stress of methomyl by using SSH technology.[Methods]Using male tilapia as the test animal,the forward and reserve libraries of SSH in the testis of tilapia under the stress of methomyl were constructed by using the SSH technology.[Results]45 expressed sequence tags (ESTs) were obtained,and 25 expressed sequence tags were successfully noted,including 13 forward libraries and 12 reverse libraries.The genes with confirmed functions were classified into five types.Genes related to catalytic activity and cell characteristics were up-regulated,while genes related to structural molecule's activity and biological process were down-regulated.The expression amount of integrin β1 was up-regulated,while serine/threonine protein kinase pim-3,Ca^2+-ATPase,Na^+-K^+-ATPase and ribosomal protein L22 were down-regulated.[Conclusions]The research results could lay a foundation for revealing the molecular mechanism of methomyl's reproductive toxicity to tilapia.展开更多
This study was conducted to find the differentially expressed genes and understand the transcriptome change characteristics in the testis of tilapia(Oreochromis niloticus) stressed by methomyl.The tilapia were exposed...This study was conducted to find the differentially expressed genes and understand the transcriptome change characteristics in the testis of tilapia(Oreochromis niloticus) stressed by methomyl.The tilapia were exposed to 200 μg/L methomyl for 30 d,and then the testis samples were collected and used for the highthroughput sequencing.The results showed that 369 significant differentially expressed genes were obtained,including 160 significantly down-regulated genes,and209 significantly up-regulated genes.The enrichment of the differentially expressed genes in ECM-receptor interaction signaling pathway and MAPK signaling pathway was obvious.The adhesion of testis tissue cells was influenced by methomyl stress,which induced the expression of related gene in ECM-receptor interaction up-regulating,such as laminins,integrin α6 and integrin β1,in order to stabilize testis tissue structure.JNK,MAP3 K and MKK4 in the JNK pathway were significantly up-regulated,which enhanced transcription factor AP-1 to promote the expression of P53,Bax and other pro-apoptotic proteins.The expression of growth-related factors in the ERK pathway of MAPK signal pathway was influenced by methomyl stress.The apoptosis-related genes and pregnancy-related genes have significant differential expression under methomyl stress,and thereby,the proliferation of reproduction cells in the testis tissue may be affected.展开更多
Tilapia were exposed to sub-lethal concentrations of 0, 0.2, 2, 20 or 200 μg/L for 30 d, and then transferred to methomyl-free water for 18 d. CAT and SOD in tilapia serum were examined at 0, 6, 12, 18, 24 and 30 d a...Tilapia were exposed to sub-lethal concentrations of 0, 0.2, 2, 20 or 200 μg/L for 30 d, and then transferred to methomyl-free water for 18 d. CAT and SOD in tilapia serum were examined at 0, 6, 12, 18, 24 and 30 d after methomyl exposure and at 18 d after transferring to methomyl-free water. There were no significant changes in antioxidants activities in tilapia exposed to 0.2 μg/L. Significant increases in SOD, CAT were observed following methomyl exposure to 2, 20 or 200 μg/L, suggesting the presence of oxidative stress. Thus, the 0.2 μg/L methomyl might be considered the no observed adverse effect level. Recovery data showed that the effects produced by lower concentration of 20 μg/L were reversible but not at the higher concentration of 200 μg/L.展开更多
基金Project supported by the National Natural Science Foundation of China(No.30600016)the National High Technology Research and Development Program of China(863 Program)(No.2007AA10Z405)+2 种基金the National Program for Sci-Tech Basic Platform Construction of China(No.2005DKA21201-2)the Program for Science and Technology Development ofJiangsu Province,China(No.BE2008669)the Program for Integration of Production,Education,and Research of Guangdong Province and Ministry of Education,China(No.2006090204007)
文摘Methomyl, an extremely toxic pesticide, is widely used in agriculture. A strain named mdw-1 capable of degrading methomyl rapidly was successfully isolated from activated sludge in this study. It could utilize methomyl as the sole carbon or nitrogen source. The optimal temperature and medium pH for its growth and methomyl biodegradation were 30℃ and 7.0, respectively. It was identified as a Paracoccus sp. according to its morphological features, physiological and biochemical characteristics, and phylogenetic analysis based on the sequence of 16S rDNA. Gas chromatography-mass spectrometry （GC-MS） analysis showed that methomyl could be completely transformed to S-methyl-N-hydroxythioacetamidate in 10 h of incubation with the isolate mdw-1.
文摘A solid phase extraction procedure of methomyl and thiodicarb from environmental water was presented. This method utilizes a 40—60 mesh activated carbon cartridge and high performance liquid chromatography (HPLC). The 40—60 mesh activated carbon works faster and yield higher adsorption efficiency. Detection limits of methomyl and thiodicarb in environmental water are 0 1 μg/L and 0 2 μg/L, respectively. Average recoveries of fortified methomyl and thiodicarb in water are in the range of 90 7%—98 8% and 88 9%—103 6%, respectively. The relative standard deviations are lower than 7%. This method is simple, rapid, accurate and precise.
文摘Modeling experimental design was used to study the main effects and the interaction effects between operational parameters in the photocatalytic degradation of pesticide methomyl. The important parameters which affect the removal efficiency of methomyl such as concentration of Fe(NO3)3, concentration of H2O2, initial concentration of the pesticide and pH. The parameters were coded as x1, x2, x3 and x4, consecutively, and were investigated at two levels (–1 and +1). The effects of individual variables and their interaction effects for dependent variables, namely, photocatalytic degradation efficiency (%) were determined. From the statistical analysis, the most effective parameters in the photocatalytic degradation efficiency were initial concentrations of the methomyl and Fe(NO3)3. The interaction between initial concentration of the pesticide and Fe(NO3)3 was the most influencing interaction. The optimum conditions that were obtained for the photocatalytic degradation of methomyl were: minimum quantity of contaminant: 6 × 10–5 mol.L–1, maximum quantity of Fe(NO3)3: 5 × 10–4 mol.L-1, initial pH of the solution: 3 and maximum quantity H2O2: 10–2 mol.L–1.
基金Supported by Basic Scientific Research Fund for Chinese Academy of Fishery Sciences(2015C02XK01)Youth Natural Scientific Foundation of Jiansu Province(BK20150117)Earmarked Fund for China Agriculture Research System(CARS-46)
文摘[Objectives]This study was conducted to construct forward and reserve libraries of suppression subtractive hybridization (SSH) in the testis of male tilapia under the stress of methomyl by using SSH technology.[Methods]Using male tilapia as the test animal,the forward and reserve libraries of SSH in the testis of tilapia under the stress of methomyl were constructed by using the SSH technology.[Results]45 expressed sequence tags (ESTs) were obtained,and 25 expressed sequence tags were successfully noted,including 13 forward libraries and 12 reverse libraries.The genes with confirmed functions were classified into five types.Genes related to catalytic activity and cell characteristics were up-regulated,while genes related to structural molecule's activity and biological process were down-regulated.The expression amount of integrin β1 was up-regulated,while serine/threonine protein kinase pim-3,Ca^2+-ATPase,Na^+-K^+-ATPase and ribosomal protein L22 were down-regulated.[Conclusions]The research results could lay a foundation for revealing the molecular mechanism of methomyl's reproductive toxicity to tilapia.
基金Supported by Fundamental Research Fund of Freshwater Fisheries Research Center of Chinese Academy of Fishery Science(2017JBFM07)Natural Science Foundation of Jiangsu Province(BK20150117)Earmarked Fund for Modern Agro-industry Technology Research System(CARS-46)。
文摘This study was conducted to find the differentially expressed genes and understand the transcriptome change characteristics in the testis of tilapia(Oreochromis niloticus) stressed by methomyl.The tilapia were exposed to 200 μg/L methomyl for 30 d,and then the testis samples were collected and used for the highthroughput sequencing.The results showed that 369 significant differentially expressed genes were obtained,including 160 significantly down-regulated genes,and209 significantly up-regulated genes.The enrichment of the differentially expressed genes in ECM-receptor interaction signaling pathway and MAPK signaling pathway was obvious.The adhesion of testis tissue cells was influenced by methomyl stress,which induced the expression of related gene in ECM-receptor interaction up-regulating,such as laminins,integrin α6 and integrin β1,in order to stabilize testis tissue structure.JNK,MAP3 K and MKK4 in the JNK pathway were significantly up-regulated,which enhanced transcription factor AP-1 to promote the expression of P53,Bax and other pro-apoptotic proteins.The expression of growth-related factors in the ERK pathway of MAPK signal pathway was influenced by methomyl stress.The apoptosis-related genes and pregnancy-related genes have significant differential expression under methomyl stress,and thereby,the proliferation of reproduction cells in the testis tissue may be affected.
基金Supported by the Special Scientific Research Funds for Central Non-profit Institutes,Chinese Academy of Fishery Sciences(No.2015C02XK01)the Natural Science Foundation of Jiangsu Province for Youth(No.BK20150117)the China Agriculture Research System(CARS-46)
文摘Tilapia were exposed to sub-lethal concentrations of 0, 0.2, 2, 20 or 200 μg/L for 30 d, and then transferred to methomyl-free water for 18 d. CAT and SOD in tilapia serum were examined at 0, 6, 12, 18, 24 and 30 d after methomyl exposure and at 18 d after transferring to methomyl-free water. There were no significant changes in antioxidants activities in tilapia exposed to 0.2 μg/L. Significant increases in SOD, CAT were observed following methomyl exposure to 2, 20 or 200 μg/L, suggesting the presence of oxidative stress. Thus, the 0.2 μg/L methomyl might be considered the no observed adverse effect level. Recovery data showed that the effects produced by lower concentration of 20 μg/L were reversible but not at the higher concentration of 200 μg/L.
