The Establishment of Laboratory Bioreactor Fro Determining the Efficiency of Mercury Removal by Pseudomonas and Enterobacter Cloacae

A mercury-polluted site in Southern Taiwan has caused great damage to the natural environment, andimpact the health of residents near the polluted sites. The goal of this study is to isolate mercury resistantmicroorganisms from the polluted site, and develop an ex situ bioremediation technique. Because theconcentration of mercury pollution in the polluted site is about 50 ppm, the medium containing 60 ppmmercury ion was used to isolate the mercury resistant bacteria. After mercury-resistant bacteria were isolated,and identification of these bacteria based on their 16S rDNA sequences was conducted. In this study, threebacteria were isolated, which was designated as B37, A45 and A46. Species identification showed that B37was closely related to Enterobacter cloacae while A45 and A46 were associated with Pseudomonas sp.Preliminary data showed that Pseudomonas sp. could remove at least 80 % of 60 ppm Hg2+ -containingmedia during 12 days incubation. Therefore, next generation sequencing (NGS), a high throughput methodfor analysis of transcriptome, will be used for delineating the transcriptome in three isolated bacteria beforeand after mercury treatment, respectively. Quantification PCR (QPCR) was performed for validation of NGSresults. The use of transposon mutagenesis can enable us to find out the mercury-resistant genes. These genescan be used as the reference genes for the development of the potentially mercury removal bacteria with highefficient. Finally, the application of the isolated bacteria or genetic bacteria to one laboratory bioreactorcontaining mercury will be conducted