Aniline-degrading microbes were cultivated and acclimated with the initial activated sludge collected from a chemical wastewater treatment plant. During the acclimation processes, aerobic granular sludge being able to...Aniline-degrading microbes were cultivated and acclimated with the initial activated sludge collected from a chemical wastewater treatment plant. During the acclimation processes, aerobic granular sludge being able to effectively degrade aniline was successfully formed, from which a preponderant bacterial strain was isolated and named as AN1. Effects of factors including pH, temperature, and second carbon/nitrogen source on the biodegradation of aniline were investigated. Results showed that the optimal conditions for the biodegradation of aniline by the strain AN1 were at pH 7.0 and 28–35°C. At the optimal pH and temperature, the biodegradation rate of aniline could reach as high as 17.8 mg/（L·hr） when the initial aniline concentration was 400 mg/L. Further studies revealed that the addition of 1 g/L glucose or ammonium chloride as a second carbon or nitrogen source could slightly enhance the biodegradation efficiency from 93.0% to 95.1%–98.5%. However, even more addition of glucose or ammonium could not further enhance the biodegradation process but delayed the biodegradation of aniline by the strain AN1. Based on morphological and physiological characteristics as well as the phylogenetic analysis of 26S rDNA sequences, the strain AN1 was identified as Candida tropicalis.展开更多
A20/AN1锌指蛋白现已快速成为利用生物技术改良植物对非生物胁迫耐性的候选靶标基因,但是对该类蛋白在植物中功能大多出于预测分析。木薯被认为是一种抗逆性较强的作物,为了给木薯抗逆分子机制研究提供线索,本研究从木薯中克隆一了个同...A20/AN1锌指蛋白现已快速成为利用生物技术改良植物对非生物胁迫耐性的候选靶标基因,但是对该类蛋白在植物中功能大多出于预测分析。木薯被认为是一种抗逆性较强的作物,为了给木薯抗逆分子机制研究提供线索,本研究从木薯中克隆一了个同时具有A20和AN1结构域的锌指蛋白基因Metip并进行了生物信息学分析。结果表明,Metip的c DNA编码区长为561 bp,推断编码的锌指蛋白Metip由186个氨基酸组成。Metip的分子量为20.17 k D;等电点为8.9;不稳定指数为40.78;脂肪指数56.18;亲水系数-0.529,由此推断Metip是一种不稳定的偏碱性的亲水蛋白;该蛋白无跨膜结构和信号肽,极有可能定位在细胞核。顺式作用元件分析发现具有7个与逆境胁迫应答有关的元件和10个光响应元件。木薯的Metip与拟南芥和水稻中的与非生物胁迫抗性相关的A20/AN1锌指蛋白具有演化亲缘关系。展开更多
The stress-associated protein SAP12 belongs to the stress-associated protein （SAP） family with 14 members in Arabidopsis thaliana. SAP12 contains two AN1 zinc fingers and was identified in diagonal 2D redox SDS-PAGE...The stress-associated protein SAP12 belongs to the stress-associated protein （SAP） family with 14 members in Arabidopsis thaliana. SAP12 contains two AN1 zinc fingers and was identified in diagonal 2D redox SDS-PAGE as a protein undergoing major redox-dependent conformational changes. Its transcript was strongly induced under cold and salt stress in a time-dependent manner similar to SAP10, with high levels after 6 h and decreasing levels after 24 and 48 h. The tran- script regulation resembled those of the stress marker peroxiredoxin PrxllD at 24 and 48 h. Recombinant SAP12 protein showed redox-dependent changes in quaternary structure as visualized by altered electrophoretic mobility in non-reducing SDS polyacrylamide gel electrophoresis. The oxidized oligomer was reduced by high dithiothreitol concentrations, and also by E. coli thioredoxin TrxA with low dithiothreitol （DTF） concentrations or NADPH plus NADPH-dependent thioredoxin reductase. From Western blots, the SAP12 protein amount was estimated to be in the range of 0.5 ngμg^-1 leaf protein. SAP12 protein decreased under salt and cold stress. These data suggest a redox state-linked function of SAP12 in plant cells particularly under cold and salt stress.展开更多
基金supported by the National Natural Science Foundation of China (No. 20977048)the National High Technology and Development Program (863) of China (No. 2009AA06Z317)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘Aniline-degrading microbes were cultivated and acclimated with the initial activated sludge collected from a chemical wastewater treatment plant. During the acclimation processes, aerobic granular sludge being able to effectively degrade aniline was successfully formed, from which a preponderant bacterial strain was isolated and named as AN1. Effects of factors including pH, temperature, and second carbon/nitrogen source on the biodegradation of aniline were investigated. Results showed that the optimal conditions for the biodegradation of aniline by the strain AN1 were at pH 7.0 and 28–35°C. At the optimal pH and temperature, the biodegradation rate of aniline could reach as high as 17.8 mg/（L·hr） when the initial aniline concentration was 400 mg/L. Further studies revealed that the addition of 1 g/L glucose or ammonium chloride as a second carbon or nitrogen source could slightly enhance the biodegradation efficiency from 93.0% to 95.1%–98.5%. However, even more addition of glucose or ammonium could not further enhance the biodegradation process but delayed the biodegradation of aniline by the strain AN1. Based on morphological and physiological characteristics as well as the phylogenetic analysis of 26S rDNA sequences, the strain AN1 was identified as Candida tropicalis.
文摘A20/AN1锌指蛋白现已快速成为利用生物技术改良植物对非生物胁迫耐性的候选靶标基因,但是对该类蛋白在植物中功能大多出于预测分析。木薯被认为是一种抗逆性较强的作物,为了给木薯抗逆分子机制研究提供线索,本研究从木薯中克隆一了个同时具有A20和AN1结构域的锌指蛋白基因Metip并进行了生物信息学分析。结果表明,Metip的c DNA编码区长为561 bp,推断编码的锌指蛋白Metip由186个氨基酸组成。Metip的分子量为20.17 k D;等电点为8.9;不稳定指数为40.78;脂肪指数56.18;亲水系数-0.529,由此推断Metip是一种不稳定的偏碱性的亲水蛋白;该蛋白无跨膜结构和信号肽,极有可能定位在细胞核。顺式作用元件分析发现具有7个与逆境胁迫应答有关的元件和10个光响应元件。木薯的Metip与拟南芥和水稻中的与非生物胁迫抗性相关的A20/AN1锌指蛋白具有演化亲缘关系。
文摘The stress-associated protein SAP12 belongs to the stress-associated protein （SAP） family with 14 members in Arabidopsis thaliana. SAP12 contains two AN1 zinc fingers and was identified in diagonal 2D redox SDS-PAGE as a protein undergoing major redox-dependent conformational changes. Its transcript was strongly induced under cold and salt stress in a time-dependent manner similar to SAP10, with high levels after 6 h and decreasing levels after 24 and 48 h. The tran- script regulation resembled those of the stress marker peroxiredoxin PrxllD at 24 and 48 h. Recombinant SAP12 protein showed redox-dependent changes in quaternary structure as visualized by altered electrophoretic mobility in non-reducing SDS polyacrylamide gel electrophoresis. The oxidized oligomer was reduced by high dithiothreitol concentrations, and also by E. coli thioredoxin TrxA with low dithiothreitol （DTF） concentrations or NADPH plus NADPH-dependent thioredoxin reductase. From Western blots, the SAP12 protein amount was estimated to be in the range of 0.5 ngμg^-1 leaf protein. SAP12 protein decreased under salt and cold stress. These data suggest a redox state-linked function of SAP12 in plant cells particularly under cold and salt stress.
