Department of Cell & Molecular Biology, Faculty of Life Sciences & Biotechnology, Shahid Beheshti University, Tehran, Iran.
Department of Cellular and Molecular Biology, Clinical and Diagnostic Immunology, KU Leuven, Leuven, Belgium.
Sci Rep. 2024 Oct 26;14(1):25490. doi: 10.1038/s41598-024-77613-1.
Dust poses environmental, geological, health, and economic concerns, and microorganisms can help mitigate these adverse consequences by improving soil properties. Microbial calcium carbonate precipitation (MICP) has been found to be an efficient strategy for increasing soil strength, reducing soil porosity, and preventing erosion; however, severe environmental conditions such as pH and high temperatures may impede this process. To identify the best strain for MICP, 60 bacteria strains were obtained from arid soils using the enrichment culture technique. They were tested for the capacity of calcium carbonate deposition and biocement synthesis in stress environments. Phenotypic characterization indicated that the majority of the bacterial isolates were gram-positive and rod-shaped, with strong catalase and oxidase enzyme activity. Furthermore, MALDI-TOF MS identification revealed that the isolates were from the Bacillus and Pseudomonas genera. Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) were used to analyze the microstructures and composition of bacterial cement. The results represented that B. subtilis isolate S56 has a higher production yield and forms distinctive calcite crystals as a result of fast urease synthesis. B. subtilis isolate S56 can be applied in situ to reduce soil erosion and dust pollution. This study reveals the potential of the B. subtilis S56 strain for soil consolidation and dust prevention in harsh environments and has the prospect of promoting its application in desertification control and ecological restoration.
粉尘会带来环境、地质、健康和经济等方面的问题，而微生物可以通过改善土壤特性来减轻这些不利影响。微生物碳酸钙沉淀（MICP）已被发现是一种提高土壤强度、降低土壤孔隙度和防止侵蚀的有效策略；然而，pH 值和高温等恶劣环境条件可能会阻碍这一过程。为了确定最适合 MICP 的菌株，我们采用富集培养技术从干旱土壤中获得了 60 株细菌菌株，并测试了它们在应激环境中碳酸钙沉积和生物水泥合成的能力。表型特征表明，大多数细菌分离物为革兰氏阳性和杆状，具有较强的过氧化氢酶和氧化酶活性。此外，MALDI-TOF MS 鉴定表明，分离物来自芽孢杆菌属和假单胞菌属。扫描电子显微镜（SEM）、能谱（EDS）和 X 射线衍射（XRD）用于分析细菌水泥的微观结构和组成。结果表明，枯草芽孢杆菌 S56 分离株具有更高的生产产量，并且由于快速合成脲酶，形成了独特的方解石晶体。枯草芽孢杆菌 S56 分离株可原位应用于减少土壤侵蚀和粉尘污染。本研究揭示了枯草芽孢杆菌 S56 菌株在恶劣环境中用于土壤固结和防尘的潜力，并有望促进其在荒漠化控制和生态恢复中的应用。
