Department of Microbiology, Mata Gujri College, Fatehgarh Sahib-140406, Punjab, India.
J Microbiol Biotechnol. 2012 May;22(5):684-9. doi: 10.4014/jmb.1109.08022.
In the present study, an efficient mercury-tolerant bacterial strain (RS-5) was isolated from heavy-metalcontaminated industrial effluent. Under shake flask conditions, 97% of the supplemented mercuric chloride was sequestered by the biomass of RS-5 grown in a tryptone soy broth. The sequestered mercuric ions were transformed inside the bacterial cells, as an XRD analysis of the biomass confirmed the formation of mercurous chloride, which is only feasible following the reaction of the elemental mercury and the residual mercuric chloride present within the cells. Besides the sequestration and intracellular transformation, a significant fraction of the mercury (63%) was also volatilized. The 16S rRNA gene sequence of RS-5 revealed its phylogenetic relationship with the family Bacillaceae, and a 98% homology with Lysinibacillus fusiformis, a Gram-positive bacterium with swollen sporangia. This is the first observation of the sequestration and volatilization of mercuric ions by Lysinibacillus sp.
在本研究中，从重金属污染的工业废水中分离出一株高效耐汞细菌（RS-5）。在摇瓶条件下，RS-5 在胰蛋白胨大豆肉汤中生长的生物量可螯合补充的氯化汞的 97%。被螯合的汞离子在细菌细胞内被转化，正如对生物量的 XRD 分析所证实的那样，这只有在元素汞与细胞内存在的残留氯化汞反应后才可行。除了螯合和细胞内转化外，大量的汞（63%）也被挥发。RS-5 的 16S rRNA 基因序列显示其与芽孢杆菌科的系统发育关系，并与革兰氏阳性菌梭形赖氨酸芽孢杆菌具有 98%的同源性，梭形赖氨酸芽孢杆菌的膨胀孢子。这是首次观察到赖氨酸芽孢杆菌属的汞离子螯合和挥发。
