Unit of Biotechnology, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan.
Biosci Biotechnol Biochem. 2021 May 25;85(6):1324-1331. doi: 10.1093/bbb/zbab069.
Biosilicification is the process by which organisms incorporate soluble, monomeric silicic acid, Si(OH)4, in the form of polymerized insoluble silica, SiO2. Biosilicifying eukaryotes, including diatoms, siliceous sponges, and higher plants, have been the targets of intense research to study the molecular mechanisms underlying biosilicification. By contrast, prokaryotic biosilicification has been less well studied, partly because the biosilicifying capability of well-known bacteria was not recognized until recently. This review summarizes recent findings on bacterial extracellular and intracellular biosilicification, the latter of which has been demonstrated only recently in bacteria. The topics discussed herein include bacterial (and archaeal) extracellular biosilicification in geothermal environments, encapsulation of Bacillus spores within a silica layer, and silicon accumulation in marine cyanobacteria. The possible contribution of bacterial biosilicification to the global silicon cycle is also discussed.
生物硅化作用是指生物体将可溶性的单体硅酸（Si(OH)4）以聚合的不溶性二氧化硅（SiO2）的形式掺入的过程。生物硅化作用的真核生物，包括硅藻、硅质海绵和高等植物，一直是研究生物硅化作用分子机制的研究热点。相比之下，原核生物的生物硅化作用研究较少，部分原因是直到最近才认识到一些著名细菌具有生物硅化作用的能力。本综述总结了近年来关于细菌细胞外和细胞内生物硅化作用的发现，后者直到最近才在细菌中得到证实。本文讨论的主题包括地热环境中细菌（和古菌）的细胞外生物硅化作用、芽孢杆菌孢子被二氧化硅层包裹以及海洋蓝藻中的硅积累。还讨论了细菌生物硅化作用对全球硅循环的可能贡献。
