Cloning and Characterization of a mer Operon From Natural Aquatic Bacteria
نویسنده
چکیده
Mercury is a highly toxic element and has caused numerous cases of human toxicity throughout history. Methylmercury is the most toxic form of mercury and bioaccumulates in fish consumed by humans. Mercury resistant bacteria exist in nature that have the ability to detoxify methylmercury by a two-enzyme system encoded on the mer operon. Currently only mer operons cloned from clinical isolates are available which may not be relevant to molecular microbial ecology studies performed in aquatic environments. The purpose of this study is to clone a mer operon from natural aquatic bacteria. Ten strains of bacteria resistant to at least 2 ppm methylmercury were isolated from aquatic habitats. Genomic libraries were created in Escherichia coli from four of these strains. One clone was obtained from strain LO13 that conferred mercury resistance. The clone has a 10.5 kb fragment that presumably contains a mer operon. A restriction map was created and the fragment was sub-cloned and sequenced. The DNA sequences were compared to known sequences on the NCBI database using a “blastx” protein search. Once characterized this mer operon will be more relevant for use in bioremediation and gene expression studies in aquatic environments.
منابع مشابه
Cloning of a mer operon from Naturally Occurring Aquatic Bacteria
Methylmercury is a toxic substance which accumulates in fish and other biota and causes toxicological problems when consumed by humans. Certain mercury resistant bacteria are able to convert the highly toxic methylmercury to a much less toxic form. Several mer operons, a group of genes which encode this function, have been cloned and characterized. However, they have been isolated and cloned fr...
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تاریخ انتشار 2004