Shenzhen Key Laboratory of Marine Bioresource and Eco-environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China.
Guangdong Province Key Laboratory of Durability for Marine Civil Engineering, The Key Laboratory on Durability of Civil Engineering in Shenzhen, College of Civil and Transportation Engineering, Shenzhen University, Shenzhen, 518060, China.
Appl Microbiol Biotechnol. 2019 Oct;103(19):7971-7982. doi: 10.1007/s00253-019-10066-z. Epub 2019 Sep 5.
A nitrogen-starving isolation strategy was developed for the first time to screen bacteria with high calcium-precipitating activity (CPA) for bioremediation of damage in porous media. Meanwhile, a novel mini-tube method based on the detection of insoluble Ca was established to evaluate the CPA of the isolates. A low-nitrogen-demanding strain B6, identified as Bacillus sp., was screened to exhibit the highest CPA (55 mM insoluble Ca). Furthermore, the effects of environmental factors and nutrient availability on B6-induced calcium precipitation were evaluated. The results show that nitrate and starch are the best nitrogen source and carbon source with optimal concentration being 4 and 2 g L, respectively. The suitable pH range for B6 to precipitate calcium is from 8.5 to 10.5. B6 can maintain the highest CPA at an initial spore concentration of 1.0 × 10 spores·mL. The optimal CaO dosage is 10 g L. Finally, the calcite precipitation is confirmed by ESEM, EDS, and XRD analysis.
首次开发了一种氮饥饿分离策略，用于筛选具有高钙沉淀活性（CPA）的细菌，以修复多孔介质中的损伤。同时，建立了一种基于不溶性 Ca 检测的新型迷你管方法，用于评估分离物的 CPA。筛选出一株具有最高 CPA（55 mM 不溶性 Ca）的低氮需求菌株 B6，鉴定为芽孢杆菌属。此外，还评估了环境因素和养分供应对 B6 诱导钙沉淀的影响。结果表明，硝酸盐和淀粉分别是最佳的氮源和碳源，最佳浓度分别为 4 和 2 g·L。B6 沉淀钙的适宜 pH 范围为 8.5 至 10.5。B6 在初始孢子浓度为 1.0×10 个孢子·mL 时可保持最高的 CPA。最佳 CaO 用量为 10 g·L。最后，通过 ESEM、EDS 和 XRD 分析证实了方解石的沉淀。
