Bacteria that are resistant to high temperatures and alkaline environments are essential for the biological repair of damaged concrete. Alkaliphilic and halotolerant Bacillus sp. AK13 was isolated from the rhizosphere of Miscanthus sacchariflorus. Unlike other tested Bacillus species, the AK13 strain grows at pH 13 and withstands 11% (w/v) NaCl. Growth of the AK13 strain at elevated pH without urea promoted calcium carbonate (CaCO₃) formation. Irregular vateritelike CaCO₃ minerals that were tightly attached to cells were observed using field-emission scanning electron microscopy. Energy-dispersive X-ray spectrometry, confocal laser scanning microscopy, and X-ray diffraction analyses confirmed the presence of CaCO₃ around the cell. Isotope ration mass spectrometry analysis confirmed that the majority of CO₃^2- ions in the CaCO₃ were produced by cellular respiration rather than being derived from atmospheric carbon dioxide. The minerals produced from calcium acetate-added growth medium formed smaller crystals than those formed in calcium lactate-added medium. Strain AK13 appears to heal cracks on mortar specimens when applied as a pelletized spore powder. Alkaliphilic Bacillus sp. AK13 is a promising candidate for self-healing agents in concrete.

中文翻译：

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嗜碱性芽孢杆菌的完整基因组和碳酸钙沉淀。 AK13 用于自修复混凝土。


耐高温和碱性环境的细菌对于受损混凝土的生物修复至关重要。嗜碱耐盐芽孢杆菌属。 AK13是从芒草根际分离得到的。与其他测试的芽孢杆菌属物种不同，AK13 菌株在 pH 13 下生长并能耐受 11% (w/v) NaCl。 AK13 菌株在没有尿素的情况下在升高的 pH 条件下生长促进了碳酸钙 (CaCO ₃ ) 的形成。使用场发射扫描电子显微镜观察到紧密附着在细胞上的不规则球霰石状CaCO ₃矿物。能量色散X射线光谱测定、共焦激光扫描显微镜和X射线衍射分析证实了细胞周围存在CaCO ₃ 。同位素质谱分析证实CaCO ₃中的大部分CO ₃ ^2-离子是由细胞呼吸产生的，而不是来自大气二氧化碳。由添加乙酸钙的生长培养基产生的矿物质形成的晶体比在添加乳酸钙的培养基中形成的矿物质更小。当作为球状孢子粉使用时，菌株 AK13 似乎可以治愈砂浆样本上的裂缝。嗜碱芽孢杆菌属。 AK13 是混凝土自修复剂的有前途的候选者。