Department of Microbiology, Mata Gujri College, Fatehgarh Sahib, 140406, Punjab, India,
Environ Sci Pollut Res Int. 2014 Sep;21(17):10186-93. doi: 10.1007/s11356-014-2951-3. Epub 2014 May 2.
The present study was conducted to isolate and explore bacterial strains with a potential to sequester lead (Pb) and tolerate other heavy metals from industrial effluents and sediments. Out of the six bacterial strains isolated from seleniferous sites of Punjab, three isolates (RS-1, RS-2, and RS-3) were screened out for further growth-associated lead sequestration and molecular characterization on the basis of their tolerance toward lead and other heavy metals. Biomass and cell-free supernatant were analyzed for lead contents using ICP-MS after growth-associated lead sequestration studies in tryptone soya broth (pH = 7.2 ± 0.2) under aerobic conditions at 37 °C temperature. Almost 82 % and 70 % divalent lead was sequestered in cell pellets of RS-1 and RS-3, respectively while only 45 % of lead was found in cell pellet of RS-2 in the first 24 h. However, significant biosequestration of lead was observed in RS-2 after 48 h of incubation with concomitant increase in biomass. Simultaneously, morphological, biochemical, and physiological characterization of selected strains was carried out. 16S rRNA gene sequence of these isolates revealed their phylogenetic relationship with class Bacillaceae, a low G + C firmicutes showing 98 % homology with Bacillus sp.
本研究旨在从工业废水和沉积物中分离和探索具有固定铅（Pb）和耐受其他重金属能力的细菌菌株。从旁遮普邦的含硒地点分离出的 6 种细菌菌株中，有 3 种（RS-1、RS-2 和 RS-3）根据其对铅和其他重金属的耐受性，在基于生长的铅固定研究中被筛选出来，用于进一步的生长相关的铅固定和分子特征分析。在有氧条件下，在 37°C 温度下，在 pH 值为 7.2 ± 0.2 的胰蛋白胨大豆肉汤中进行生长相关的铅固定研究后，使用 ICP-MS 分析生物量和无细胞上清液中的铅含量。在 RS-1 和 RS-3 的细胞沉淀中，分别固定了 82%和 70%的二价铅，而在 RS-2 的细胞沉淀中，在前 24 小时内仅发现了 45%的铅。然而，在 48 小时的孵育后，在 RS-2 中观察到显著的铅生物固定，同时伴随着生物量的增加。同时，对选定菌株进行了形态、生化和生理特征分析。这些分离株的 16S rRNA 基因序列显示它们与芽孢杆菌科（Bacillaceae）的关系，这是一种低 G+C 的Firmicutes，与芽孢杆菌属（Bacillus sp.）具有 98%的同源性。
