Department of Biotechnology, Thapar Institute of Engineering & Technology, Patiala, Punjab, 147004, India.
Environ Monit Assess. 2023 Aug 7;195(9):1019. doi: 10.1007/s10661-023-11616-9.
Due to anthropogenic activities, heavy metals such as cadmium (Cd) and arsenic (As) are one of the most toxic xenobiotics contaminating water, thus affecting human health and the environment. The objective of the present investigation was to study the effect of ureolytic bacteria Bacillus paramycoides-MSR1 for the bioremediation of Cd and As from contaminated water. The B. paramycoides showed high resistance to heavy metals, Cd and As, with minimum inhibitory concentration (MIC) of 12.84 μM and 48.54 μM, respectively. The urease activity and calcium carbonate (CaCO) precipitation were evaluated in artificial wastewater with different concentrations of Cd (0, 10, 20, 30, 40, 50, and 60 μM) and As (0, 20, 40, 60, 80, and 100 μM). The maximum urease activity in Cd-contaminated artificial wastewater was observed after 96 hours, which showed a 76.1% decline in urease activity as the metal concentration increased from 0 to 60 μM. Similarly, 14.1% decline in urease activity was observed as the concentration of As was increased from 0 to 100 μM. The calcium carbonate precipitation at the minimum inhibitory concentration of Cd and As-contaminated artificial wastewater was 189 and 183 mg/100 ml, respectively. The percentage removal of metal from artificially contaminated wastewater with varied concentrations was analyzed using atomic absorption spectroscopy (AAS). After 168 hours of incubation, 93.13% removal of Cd and 94.25% removal of As were observed. Microstructural analysis proved the presence of calcium carbonate in the form of calcite, confirming removal of cadmium and arsenic by microbially induced calcium carbonate precipitation (MICCP) to be promising technique for water decontamination.
由于人为活动，镉 (Cd) 和砷 (As) 等重金属是污染水的最有毒异生物质之一，从而影响人类健康和环境。本研究的目的是研究解脲菌 Bacillus paramycoides-MSR1 对受污染水中 Cd 和 As 的生物修复作用。B. paramycoides 对重金属 Cd 和 As 具有高抗性，最小抑制浓度 (MIC) 分别为 12.84 μM 和 48.54 μM。在不同浓度 Cd（0、10、20、30、40、50 和 60 μM）和 As（0、20、40、60、80 和 100 μM）的人工废水中评估了脲酶活性和碳酸钙 (CaCO) 沉淀。在 Cd 污染的人工废水中，96 小时后观察到最大脲酶活性，随着金属浓度从 0 增加到 60 μM，脲酶活性下降了 76.1%。同样，当 As 浓度从 0 增加到 100 μM 时，脲酶活性下降了 14.1%。在 Cd 和 As 污染的人工废水中最低抑制浓度下的碳酸钙沉淀分别为 189 和 183 mg/100 ml。使用原子吸收光谱法 (AAS) 分析了不同浓度人工污染废水中金属的去除百分比。孵育 168 小时后，观察到 Cd 去除率为 93.13%，As 去除率为 94.25%。微观结构分析证明了方解石形式的碳酸钙的存在，证实了微生物诱导碳酸钙沉淀 (MICCP) 去除镉和砷是一种很有前途的水净化技术。
