The focus of the present study is to isolate and identify magnetotactic bacteria from fresh water sediments in Salem region, Tamil Nadu. Fresh water sediments were collected and characterized by X-ray diffraction to detect the crystalline nature of particles. Totally 12 isolates were screened for the metal biosorption efficiency in modified nutrient agar plates with 10 mg (lower concentration) of four different metals viz., manganese chloride, zinc sulphate, copper sulphate and potassium dichromate. Followed by testing their ability to tolerate higher concentration of metals viz., 20 mg, 30 mg, 50 mg, 70 mg, 90 mg and 150 mg/50 ml was analyzed. Only four bacteria survived the highest concentration of manganese and zinc (3000 µg/ml), CuSO₄ and K₂Cr₂O₇ at a concentration of 1400 µg/ml and 1800 µg/ml, respectively. The four bacterial strains Stenotrophomonas maltophilia, two Pseudomonas aeruginosa strains and Achromobacter xylosoxidans were grown in modified nutrient broth (NB) and Luria Bertani (LB) incorporated with metals such as manganese, zinc, copper and chromium and tested for their efficacy to sustain metal stress. Since the two bacterial strains (SBY and KY1) were able to grow in both medium with a potential to with stand higher metal concentration these strains were further studied. A metal tolerant magnetotactic bacterial strain Pseudomonas aeruginosa SBY was confirmed by TEM analysis to detect the accumulated metal within the cell. As bacterial strains were capable of tolerating higher concentration of metal, they may have a vital role in environmental bioremediation.

本研究的重点是从泰米尔纳德邦塞勒姆地区的淡水沉积物中分离和鉴定趋磁细菌。收集淡水沉积物并通过 X 射线衍射表征以检测颗粒的结晶性质。在含有 10 毫克（较低浓度）四种不同金属，即氯化锰、硫酸锌、硫酸铜和重铬酸钾的改良营养琼脂平板中，对总共 12 个分离株的金属生物吸附效率进行了筛选。随后测试了它们耐受更高浓度金属的能力，即分析了 20 mg、30 mg、50 mg、70 mg、90 mg 和 150 mg / 50 ml。只有四种细菌在最高浓度的锰和锌 (3000 µg/ml)、CuSO ₄和 K ₂ Cr ₂ O 中存活₇浓度分别为 1400 µg/ml 和 1800 µg/ml。四种细菌菌株嗜麦芽窄食单胞菌、两种铜绿假单胞菌菌株和木糖氧化无色杆菌在添加了锰、锌、铜和铬等金属的改良营养肉汤 (NB) 和 Luria Bertani (LB) 中生长，并测试其维持金属压力的功效. 由于两种细菌菌株（SBY 和 KY1）能够在两种培养基中生长，并有可能承受更高的金属浓度，因此进一步研究了这些菌株。一株耐金属趋磁细菌铜绿假单胞菌通过 TEM 分析证实了 SBY，以检测细胞内积累的金属。由于细菌菌株能够耐受更高浓度的金属，因此它们可能在环境生物修复中发挥重要作用。