Jain Sourabh, Bhatt Arun
Uttarakhand Technical University, Dehradun, India.
National Research Centre on Plant Biotechnology, IARI Campus, Pusa, New Delhi, India.
3 Biotech. 2014 Jun;4(3):297-304. doi: 10.1007/s13205-013-0155-z. Epub 2013 Jul 18.
Cadmium-resistant strains psychrotolerant Pseudomonas putida SB32 and alkalophilic Pseudomonas monteilli SB35 were originally isolated from the soil of Semera mines, Palamau, Jharkhand, India. Further, to unravel the mechanism involved in cadmium resistance, plasmid DNA was isolated from the strains and subjected to amplification of the czc gene, which is responsible for the efflux of three metal cations, viz. Co, Zn and Cd, from the cell. Furthermore, the amplicon was cloned into pDrive cloning vector and sequenced. When compared with the available database, the sequence homology of the cloned gene showed the presence of a partial czcA gene sequence, thereby indicating the presence of a plasmid-mediated efflux mechanism for resistance in both strains. These results were further confirmed by atomic absorption spectroscopy and transmission electron microscopy. Moreover, the strains were characterized functionally for their bioremediation potential in cadmium-contaminated soil by performing an in situ experiment using soybean plant. A marked increase in agronomical parameters was observed in presence of both strains. Further, the concentration of metal ions decreased in both plants and soil in the presence of these bioinoculants.
耐镉菌株嗜冷恶臭假单胞菌SB32和嗜碱蒙氏假单胞菌SB35最初是从印度贾坎德邦帕拉马乌塞梅拉矿的土壤中分离出来的。此外，为了阐明耐镉机制，从这些菌株中分离出质粒DNA，并对负责三种金属阳离子（即钴、锌和镉）从细胞中流出的czc基因进行扩增。此外，将扩增子克隆到pDrive克隆载体中并进行测序。与现有数据库相比，克隆基因的序列同源性显示存在部分czcA基因序列，从而表明这两种菌株中都存在质粒介导的抗性功能流出机制。这些结果通过原子吸收光谱法和透射电子显微镜进一步得到证实。此外，通过使用大豆植株进行原位实验，对这些菌株在镉污染土壤中的生物修复潜力进行了功能表征。在两种菌株存在的情况下，观察到农艺参数显著增加。此外，在这些生物接种剂存在的情况下，两种植物和土壤中的金属离子浓度均降低。
