請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/23857
標題: | 利用生物方法檢測環境中的污染物 Biological assays for the detection and measurement of environmental pollutants |
作者: | Yueh-Fen Li 李悅芬 |
指導教授: | 廖秀娟 |
關鍵字: | 細菌生物偵測器,甲苯,生物獲取率,砷,生物指標, Bacterial biosensors,Toluene,Bioavailability,Arsenic,Biomarker, |
出版年 : | 2006 |
學位: | 碩士 |
摘要: | The environmental pollution threatens human health as well as wildlife in the past decades. As a result, it is necessary to develop sensitive, effective, and inexpensive methods which can efficiently monitor and determine the presence and amount of hazards in the environment. In this study, we report two biologically analytical methods to detect and measure the environmental pollutants.
Firstly, we describe the construction and characterization of the fluorescent and the luminescent Escherichia coli whole-cell biosensors for the detection of bioavailable toluene and its related compounds. The biosensor strains Escherichia coli DH5α carrying pTOLGFP or pTOLLUX were developed based on the expression of reporter genes: gfp or luxCDABE under the control of the Pu promoter and xylR gene of Pseudomonas putita plasmid pWW0. To assess their applicability for analyzing environmentally relevant samples, the biosensor harboring pTOLLUX was field-tested on water and soil samples collected from toluene contaminated sites. Our results demonstrate that nonpathogenic bacterial biosensors developed in the present study is useful and applicable in determining the bioavailability of toluene and its related compounds with high sensitivity in environmental samples, and they suggest a potential for its inexpensive application in field-ready tests. Secondly, alterations of glutathione levels as well as the mRNA levels of HSP70 in tilapia fish were investigated under arsenite exposure. Tilapia fish were exposed to waterborne arsenite (0, 1, 2, and 4 ppm, respectively) for 1 day and 3 day exposure duration. After the treatment, arsenite concentrations in gill, intestine, liver, and muscle were measured by means of inductively coupled plasma (ICP). Meanwhile, the GSH contents in fish tissues were measured and the mRNA expression of HSP70 was analyzed with semi-quantitative RT-PCR. Our results indicate that HSP70 mRNA expression and GSH levels exhibited a correlation with the arsenite exposure condition as well as the arsenic accumulation, indicating their usefulness as the biomarker of arsenite exposure in tilapia. Furthermore, the bioaccumulations of arsenic differentially distributed in various fish tissues assist in providing information of bioavailability. We conclude that biological assays, such as bacterial biosensors and biomarker presented in this study, for detecting and determining the environmental contaminants can compensate the disadvantages of traditional analytical methods such as not capable to reflect the bioavailability and failing to show the effects of contaminants mixtures on organisms, and thus providing critical data that can be useful in risk assessment. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/23857 |
全文授權: | 未授權 |
顯示於系所單位: | 生物環境系統工程學系 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-95-1.pdf 目前未授權公開取用 | 2.69 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。