Advanced Instrumentation Research Facility, Jawaharlal Nehru University, New Delhi 110067, India; School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
Bioresour Technol. 2018 Apr;253:368-371. doi: 10.1016/j.biortech.2018.01.081. Epub 2018 Jan 20.
The thermo-alkalotolerant bacterium exhibiting heightened extracellular carbonic anhydrase (CA) activity, survived at 100 mM sodium bicarbonateand 5% gaseous CO was identified as Bacillus sp. by 16S rRNA sequencing. Extracellular carbonic anhydrase was purified by ammonium sulfate precipitation, gel filtration chromatography and affinity chromatography with a yield of 46.61% and specific activity of 481.66 U/mg. The size of purified carbonic anhydrase was approximately 28 kDa in SDS-PAGE gel filtration and further their role in calcium carbonate production was correlated. The purified enzyme was stable with half-life of 25.36 min at 90 °C and pH 8. K and Vmax values of the enzyme were 1.77 mg/mL and 385.69 U/mg respectively. The production of calcite was confirmed by Scanning Electron Microscopy (SEM) analysis, FTIR, and Energy-Dispersive X-ray (EDX) analysis. Carbonic anhydrase and calcite deposition coupled with CO fixingbacteria is a significant approach for CO sequestration.
一株嗜热耐碱细菌，其胞外碳酸酐酶（CA）活性较高，在 100mM 碳酸氢钠和 5%气态 CO 环境中存活，通过 16S rRNA 测序鉴定为芽孢杆菌属。胞外碳酸酐酶通过硫酸铵沉淀、凝胶过滤层析和亲和层析进行纯化，产率为 46.61%，比活为 481.66U/mg。SDS-PAGE 凝胶过滤层析中纯化的碳酸酐酶大小约为 28kDa，并进一步研究了其在碳酸钙生产中的作用。该纯化酶在 90°C 和 pH8 下半衰期为 25.36min，稳定性良好。酶的 K 和 Vmax 值分别为 1.77mg/mL 和 385.69U/mg。通过扫描电子显微镜（SEM）分析、傅里叶变换红外光谱（FTIR）和能谱（EDX）分析证实了方解石的生成。碳酸酐酶和方解石的沉积与固定 CO2 的细菌相结合，是 CO2 封存的一种重要方法。
