Mercury remediation potential of a mercury resistant strain Sphingopyxis sp. SE2 isolated from contaminated soil

详细信息    查看全文

• 作者：Khandaker Rayhan Mahbub ^{KhandakerRayhan.Mahbub@uon.edu.au krmjissan@gmail.com} ; Kannan Krishnan ; Ravi Naidu ; Mallavarapu Megharaj ; ^{megh.mallavarapu@newcastle.edu.au}
• 关键词：Mercury resistance ; Sphingopyxis ; Mercury volatilization ; Mercury remediation ; Mercury reductase
• 刊名：Journal of Environmental Sciences
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：51
• 期：Complete
• 页码：128-137
• 全文大小：1306 K
• 卷排序：51

文摘

A mercury resistant bacterial strain SE2 was isolated from contaminated soil. The 16s rRNA gene sequencing confirms the strain as Sphingopyxis belongs to the Sphingomonadaceae family of the α-Proteobacteria group. The isolate showed high resistance to mercury with estimated concentrations of Hg that caused 50% reduction in growth (EC50) of 5.97 and 6.22 mg/L and minimum inhibitory concentrations (MICs) of 32.19 and 34.95 mg/L in minimal and rich media, respectively. The qualitative detection of volatilized mercury and the presence of mercuric reductase enzyme proved that the strain SE2 can potentially remediate mercury. ICP-QQQ-MS analysis of the remaining mercury in experimental broths indicated that a maximum of 44% mercury was volatilized within 6 hr by live SE2 culture. Furthermore a small quantity (23%) of mercury was accumulated in live cell pellets. While no volatilization was caused by dead cells, sorption of mercury was confirmed. The mercuric reductase gene merA was amplified and sequenced. Homology was observed among the amino acid sequences of mercuric reductase enzyme of different organisms from α-Proteobacteria and ascomycota groups.