Magnel Laboratory for Concrete Research, Ghent University, Technologiepark Zwijnaarde 904, 9052, Ghent, Belgium.
Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
Appl Microbiol Biotechnol. 2017 Jun;101(12):5101-5114. doi: 10.1007/s00253-017-8260-2. Epub 2017 Apr 1.
The suitability of using a spore-forming ureolytic strain, Bacillus sphaericus, was evaluated for self-healing of concrete cracks. The main focus was on alkaline tolerance, calcium tolerance, oxygen dependence, and low-temperature adaptability. Experimental results show that B. sphaericus had a good tolerance. It can grow and germinate in a broad range of alkaline pH. The optimal pH range is 7 ∼ 9. High alkaline conditions (pH 10 ∼ 11) slow down but not stop the growth and germination. Oxygen was strictly needed during bacterial growth and germination, but not an essential factor during bacterial urea decomposition. B. sphaericus also had a good Ca tolerance, especially at a high bacterial concentration of 10 cells/mL; no significant influence was observed on bacterial ureolytic activity of the presence of 0.9M Ca. Furthermore, at a low temperature (10 °C), bacterial spores germinated and revived ureolytic activity with some retardation. However, this retardation can be counteracted by using a higher bacterial concentration and by supplementing yeast extract. It can be concluded that B. sphaericus is a suitable bacterium for application in bacteria-based self-healing concrete.
研究了一种产芽孢的脲酶分解菌——球形芽孢杆菌（Bacillus sphaericus）在混凝土自修复中的适用性。主要关注其碱性耐受性、钙离子耐受性、需氧性和低温适应性。实验结果表明，B. sphaericus 具有良好的耐受性。它可以在碱性 pH 值较宽的范围内生长和发芽。最佳 pH 值范围为 7∼9。高碱性条件（pH 10∼11）虽然减缓但不会阻止其生长和发芽。细菌生长和发芽过程中严格需要氧气，但在细菌分解脲的过程中不是必需因素。B. sphaericus 对钙离子也有很好的耐受性，特别是在细菌浓度为 10 细胞/mL 时；在存在 0.9M Ca 的情况下，对细菌脲酶活性没有显著影响。此外，在低温（10°C）下，细菌孢子发芽并恢复脲酶活性，但有一定的延迟。然而，这种延迟可以通过使用更高的细菌浓度和补充酵母提取物来抵消。可以得出结论，B. sphaericus 是一种适用于基于细菌的自修复混凝土的细菌。
