The use of heat- and alkali-resistant bacteria is essential for the biological repair of damaged concrete. Lysinibacillus boronitolerans YS11 was isolated from the rhizosphere of Miscanthus sacchariflorus. The increased pH in the urea-minus condition during the growth of the YS11 strain promoted calcium carbonate (CaCO₃) formation. To identify the optimum medium that promoted the growth of the YS11 strain, a Plackett-Burman design was conducted for the screening process. Consequently, malt powder, rice bran, (NH₄)₂SO₄, and corn syrup were chosen to enhance YS11 growth. The optimization of these four useful factors was carried out using a central composite design. To obtain higher survivability in mortar, the sporulation process is essential, and additional factors such as Mn²⁺, Fe²⁺, and Ca²⁺ were found to contribute to sporulation. A mixture of L. boronitolerans YS11 spore powder, cement, paste, sand, yeast extract, calcium lactate, and water showed a healing effect on a 0.3 mm mortar crack in 7 days. Furthermore, calcium carbonate precipitation was observed over the crack surface. Thus, we confirmed that mortar treated with YS11 spore powder was effective in healing micro-cracks in concrete.

中文翻译：

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利用经济养分优化自修复混凝土的细菌孢子形成

使用耐热和耐碱细菌对于受损混凝土的生物修复至关重要。Lysinibacillus boronitolerans YS11从根际分离荻。在YS11菌株生长过程中，尿素减量条件下pH的升高促进了碳酸钙（CaCO ₃）的形成。为了确定促进YS11菌株生长的最佳培养基，对筛选过程进行了Plackett-Burman设计。因此，麦芽粉，米糠，（NH ₄）₂ SO ₄选择玉米糖浆以增强YS11的生长。使用中央复合设计对这四个有用因素进行了优化。为了在砂浆中获得更高的生存能力，形成孢子的过程是必不可少的，并且发现其他因素（例如Mn 2 ⁺，Fe ²⁺和Ca ^2+）也有助于形成孢子。的混合物L. boronitolerans YS11孢子粉，水泥，粘贴，沙子，酵母提取物，乳酸钙和水显示对在7天后为0.3毫米的裂纹砂浆一个治愈效果。此外，在裂纹表面上观察到碳酸钙沉淀。因此，我们证实用YS11孢子粉处理的砂浆对修复混凝土中的微裂纹是有效的。