Orji O U, Awoke J N, Aja P M, Aloke C, Obasi O D, Alum E U, Udu-Ibiam O E, Oka G O
Department Biochemistry, Ebonyi State University, Abakaliki, Nigeria.
Alex Ekwueme Federal University, Ndufu-Alike, Ikwo, Nigeria.
Heliyon. 2021 Jul 10;7(7):e07512. doi: 10.1016/j.heliyon.2021.e07512. eCollection 2021 Jul.
Environmental contaminations by heavy metals are currently an increasing public health concern globally. One key challenge of these toxic metals is the extremely difficulties involved in their detoxification from the environment and effluents because of their non-degradability. An efficient biologic agent with potentials of remediating these toxic metals may ease these ever-increasing problems. We reported toxic metals tolerance and bioremediation potentials of novel bacteria sp. Strains USL2S, USL4W and USL5W isolated from Uburu salt lake, Ebonyi State, Nigeria. The phenotypic characteristics and the 16S rRNA gene analyses revealed that USL2S strain belongs to the genus whereas USL4W and USL5W strains belong to the genus The bacteria isolates grew well in media containing 5-15 % of sodium chloride. The bacteria isolate showed capacity to tolerate 50.0 mM Hg and Pb, 17.0, 12.50 and 4.0mM Ni, Cd, and Zn respectively in solid media. putida A4W Strain also tolerated 16.0 mM Cu, while sp. Strain USL2S, USL5W Strain tolerated 4.0 mM each. AAS analyses showed 85, 95, and 95 % Hg; 97.13, 98.89, and 97.55 % Pb; 73.33, 77.42 and 69.72 Cd; 88.06, 99.54, and 97.91 % Ni; 100, 100 and 83.62% Cu; 42.30, 84.52 and 98.80 % Zn removal from media broth incorporated with the tested metals by sp. USL2S, sp. Strain USL5W and sp. USL4W respectively. We therefore recommend these novel moderately halophilic and metal tolerant isolates as possible biologic agents for effective bioremediation of mercury, lead, cadmium, nickel, copper and zinc in contaminated environments and effluents.
目前，重金属对环境的污染在全球范围内日益引起公众对健康的关注。这些有毒金属面临的一个关键挑战是，由于它们不可降解，要从环境和废水中将其解毒极其困难。一种具有修复这些有毒金属潜力的高效生物制剂可能会缓解这些日益严重的问题。我们报告了从尼日利亚埃邦伊州乌布卢盐湖分离出的新型细菌菌株USL2S、USL4W和USL5W对有毒金属的耐受性及生物修复潜力。表型特征和16S rRNA基因分析表明，USL2S菌株属于 属，而USL4W和USL5W菌株属于 属。这些细菌分离株在含有5 - 15%氯化钠的培养基中生长良好。在固体培养基中，这些细菌分离株分别显示出能够耐受50.0 mM的汞和铅、17.0 mM、12.50 mM和4.0 mM镍、镉和锌的能力。恶臭假单胞菌A4W菌株也能耐受16.0 mM铜，而 菌株USL2S、 菌株USL5W各能耐受4.0 mM铜。原子吸收光谱分析显示，USL2S菌株、 菌株USL5W和 菌株USL4W分别从添加了测试金属的培养基肉汤中去除了85%、95%和95%的汞；97.13%、98.89%和97.55%的铅；73.33%、77.42%和69.72%的镉；88.06%、99.54%和97.91%的镍；100%、100%和83.62%的铜；42.30%、84.52%和98.80%的锌。因此，我们推荐这些新型中度嗜盐且耐金属的分离株作为可能的生物制剂，用于在受污染环境和废水中有效生物修复汞、铅、镉、镍、铜和锌。
