Abstract Sporosarcina pasteurii is widely used in the application of microbially induced carbonate precipitation (MICP) for various applications, such as ground reinforcement, erosion mitigation or stabilization of sand foreshore slopes. This study focuses on the effect of thallus resuspended by the fresh medium (RF) on urea hydrolysis, MICP, and sand reinforcement compared with untreated biological solutions (US) with high microbial concentration. The principle is investigated by tests on thallus resuspended by saline solution [NaCl (0.9%)] (RS) and supernatant (SS). The results indicate that the addition of the fresh medium is insignificant for promoting MICP and even has a slightly negative effect on urea hydrolysis and sand improvement for stationary phase bacteria. The ability of US to hydrolyze urea and MICP is derived from two sources: urease existing in the cell bodies and free urease existing in solution for lysis of partial cells, with urease in cells accounting for the majority. The preferable sand reinforcement of US is primarily due to the high amount of carbonate precipitation and formation of non-biological calcium carbonate located primarily in the pores. The results indicate that the preference of US in various engineering applications with lower cost for the realizable reinforcement.

中文翻译：

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不同生物溶液对微生物诱导碳酸盐沉淀和砂土加固的影响

摘要 Sporosarcina pasteurii 广泛应用于微生物诱导碳酸盐沉淀 (MICP) 的各种应用，例如地基加固、侵蚀减缓或沙前岸边坡的稳定。本研究的重点是与具有高微生物浓度的未经处理的生物溶液 (US) 相比，通过新鲜培养基 (RF) 重新悬浮的菌体对尿素水解、MICP 和砂加固的影响。通过对用盐水溶液 [NaCl (0.9%)] (RS) 和上清液 (SS) 重新悬浮的菌体进行测试来研究该原理。结果表明，添加新鲜培养基对MICP的促进作用微乎其微，甚至对固定相细菌的尿素水解和砂质改良有轻微的负面影响。US 水解尿素和 MICP 的能力来自两个来源：存在于细胞体中的脲酶和存在于溶解部分细胞的溶液中的游离脲酶，其中以细胞中的脲酶占大多数。US 的优选砂增强主要是由于大量的碳酸盐沉淀和主要位于孔隙中的非生物碳酸钙的形成。结果表明，美国在各种工程应用中偏爱可实现的加固成本较低。