Lee Yun Suk, Park Woojun
Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea.
AMB Express. 2019 Apr 11;9(1):49. doi: 10.1186/s13568-019-0773-x.
Microbially induced calcium carbonate (CaCO) precipitation (MICP) is a process where microbes induce condition favorable for CaCO formation through metabolic activities by increasing the pH or carbonate ions when calcium is near. The molecular and ecological basis of CaCO precipitating (CCP) bacteria has been poorly illuminated. Here, we showed that increased pH levels by deamination of amino acids is a driving force toward MICP using alkalitolerant Lysinibacillus boronitolerans YS11 as a model species of non-ureolytic CCP bacteria. This alkaline generation also facilitates the growth of neighboring alkaliphilic Bacillus sp. AK13, which could alter characteristics of MICP by changing the size and shape of CaCO minerals. Furthermore, we showed CaCO that precipitates earlier in an experiment modifies membrane rigidity of YS11 strain via upregulation of branched chain fatty acid synthesis. This work closely examines MICP conditions by deamination and the effect of MICP on cell membrane rigidity and crystal formation for the first time.
微生物诱导碳酸钙（CaCO）沉淀（MICP）是一个过程，即当附近存在钙时，微生物通过代谢活动，通过提高pH值或增加碳酸根离子，诱导有利于CaCO形成的条件。碳酸钙沉淀（CCP）细菌的分子和生态基础一直未得到充分阐明。在这里，我们以耐碱的硼耐受赖氨酸芽孢杆菌YS11作为非尿素分解CCP细菌的模型物种，表明氨基酸脱氨导致的pH值升高是MICP的驱动力。这种碱性的产生也促进了邻近嗜碱芽孢杆菌AK13的生长，AK13可以通过改变CaCO矿物的大小和形状来改变MICP的特性。此外，我们还表明，在实验中较早沉淀的CaCO通过上调支链脂肪酸合成来改变YS11菌株的膜刚性。这项工作首次通过脱氨密切研究了MICP条件以及MICP对细胞膜刚性和晶体形成的影响。
