Shafique Maria, Jawaid Aqsa, Rehman Yasir
Department of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan.
Department of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan.
C R Biol. 2017 Jun-Jul;340(6-7):330-338. doi: 10.1016/j.crvi.2017.05.002. Epub 2017 Jul 3.
Remediation of toxic metal-polluted sites by microorganisms is an environment-friendly remediation technique. Multi-metal-resistant bacteria were isolated from a wastewater treatment plant showing resistance against As(III), As(V), Cr, Co, Cu, Cd, Hg, Ni, Pb, Se and Zn. Maximum resistance against all metals was shown by the bacterial isolate MX-6 (As 20mM, Cd 30mM, Cr 5.0mM, Co 25mM, Cu 25mM, Ni 20mM, Zn 30mM, Pb 15mM, Se 20mM and Hg 2.5mM), which was identified as Pseudomonas sp. through 16S rDNA sequencing. Pseudomonas sp. MX-6 reduced 506μM As(V) and also oxidized 160μM As(III). The genes for As, Cd, Se and Zn resistance in Pseudomonas sp. MX-6 were found to be plasmid borne, as indicated by transformation. Pseudomonas sp. MX-6 produced 49.37μg·mL IAA and was also positive for HCN production and phosphate solubilisation. The bacterial isolate also supported Vigna radiata growth, both in the absence and presence of the aforementioned metals. Such bacteria can be used as biofertilizers to reclaim the polluted lands and to enhance crop production in metal-contaminated soils.
利用微生物修复有毒金属污染场地是一种环境友好型修复技术。从一家污水处理厂分离出了对砷（III）、砷（V）、铬、钴、铜、镉、汞、镍、铅、硒和锌具有抗性的多金属抗性细菌。细菌分离株MX - 6对所有金属表现出最大抗性（砷20mM、镉30mM、铬5.0mM、钴25mM、铜25mM、镍20mM、锌30mM、铅15mM、硒20mM和汞2.5mM），通过16S rDNA测序鉴定为假单胞菌属。假单胞菌属MX - 6还原了506μM的砷（V），还氧化了160μM的砷（III）。转化结果表明，假单胞菌属MX - 6中砷、镉、硒和锌抗性基因是质粒携带的。假单胞菌属MX - 6产生了49.37μg·mL的吲哚 - 3 - 乙酸（IAA），并且在产生氰化氢和溶解磷方面呈阳性。该细菌分离株在上述金属存在和不存在的情况下均支持绿豆生长。这类细菌可用作生物肥料来开垦污染土地并提高金属污染土壤中的作物产量。
