School of Environmental Sciences, Mahatma Gandhi University, Kottayam, Kerala, India.
National Center for Antarctic and Ocean Research, Vasco-da-Gama, Goa, India.
J Basic Microbiol. 2018 Apr;58(4):286-295. doi: 10.1002/jobm.201700496. Epub 2018 Jan 31.
Mercury tolerant bacteria Pseudarthrobacter oxydans strain MM20 and Pseudomonas frederiksbergensis strain SS18 were isolated from the tundra ecosystem of Ny-Ålesund, Svalbard, where commercial exploitation of the coal existed till 1960s. Minimum inhibitory concentration (MIC), mercury removal, mercury biosorption, and antibiotic resistance of these strains were analyzed. P. frederiksbergensis strain SS18 showed high tolerance (2.0 ppm) to mercury than P. oxydans strain MM20 (1.5 ppm). Mercury removal and biosorption studies were carried out in liquid media containing 1.0 ppm mercury. More than 90% of mercury was removed from the culture media by the selected strains. The mercury biosorption assay revealed that a part of mercury was accumulated in cell pellets and was 22 and 25% respectively for P. oxydans strain MM20 and P. frederiksbergensis strain SS18. Fourier transform infrared study revealed that alkyl halide, alkynes, alcoholic, aliphatic and aromatic amines, alkanes, nitro compound, primary amines, carboxylic acid, alkenes, and amide groups play a major role in the development of tolerance towards mercury. Out of eleven antibiotics tested, P. oxydans strain MM20 was found to be resistant to lincomycin and novobiocin while P. frederiksbergensis strain SS18 was found to be resistant to seven antibiotics. Our study demonstrates that under experimental conditions, bacterial isolates undergo detailed structural and functional changes to tolerate as well as immobilize toxic elements like mercury.
从斯瓦尔巴群岛新奥尔松的冻原生态系统中分离出了耐汞细菌假诺卡氏菌 MM20 菌株和弗雷德里克斯堡假单胞菌 SS18 菌株，20 世纪 60 年代以前，这里曾有商业性开采煤炭。对这些菌株进行了最小抑菌浓度（MIC）、汞去除、汞生物吸附和抗生素耐药性分析。弗雷德里克斯堡假单胞菌 SS18 菌株对汞的耐受性（2.0ppm）高于假诺卡氏菌 MM20 菌株（1.5ppm）。在含有 1.0ppm 汞的液体培养基中进行了汞去除和生物吸附研究。所选菌株可去除超过 90%的培养基中的汞。汞生物吸附试验表明，部分汞被细胞沉淀积累，假诺卡氏菌 MM20 菌株和弗雷德里克斯堡假单胞菌 SS18 菌株分别为 22%和 25%。傅里叶变换红外研究表明，烷基卤化物、炔烃、醇、脂肪族和芳香族胺、烷烃、硝基化合物、伯胺、羧酸、烯烃和酰胺基在耐汞能力的发展中起主要作用。在所测试的 11 种抗生素中，发现假诺卡氏菌 MM20 菌株对林可霉素和新生霉素有耐药性，而弗雷德里克斯堡假单胞菌 SS18 菌株对 7 种抗生素有耐药性。我们的研究表明，在实验条件下，细菌分离株会发生详细的结构和功能变化，以耐受和固定有毒元素，如汞。
