Conservation of ornamental stone by Myxococcus xanthus-induced carbonate biomineralization
Conservation of ornamental stone by Myxococcus xanthus-induced carbonate biomineralization
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DOI：
10.1128/aem.69.4.2182-2193.2003
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发表时间：
2003-04-01
影响因子：
4.4
通讯作者：
Gonzalez-Muñoz, MT
中科院分区：
文献类型：
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作者：
Rodriguez-Navarro, C;Rodriguez-Gallego, M;Gonzalez-Muñoz, MT
几十年来，城市地区日益严重的环境污染已经危及到纪念碑和雕像中的碳酸盐石的生存。为了保护和巩固这些艺术品，采用了许多保护措施。然而，它们中的大多数要么在固化过程中释放出危险气体，要么收效甚微。细菌诱导的碳酸盐矿化被认为是保护变质观赏石的一种新颖而环保的策略。然而，这种方法似乎显示出孔隙的固结和堵塞不足。在这里，我们报道了黄粘球菌诱导的碳酸钙沉淀有效地保护和巩固多孔观赏石灰岩。新形成的碳酸盐通过沉积在孔隙壁上而不堵塞它们来粘合方解石颗粒。超声测试表明，这些新的碳酸盐晶体强烈附着在基体上，主要是由于在先前存在的方解石晶粒上外延生长。新晶体比原石的方解石颗粒更耐应力，因为它们是有机-无机复合材料。培养基中磷酸盐浓度的变化会导致局部pH值和细菌产量的变化。这些影响新水泥的结构和沉淀的CaCO3多晶型（水晶石或方解石）的类型。培养基成分的控制为控制细菌生物矿化创造了新的方法，未来可应用于观赏石的保护。
Increasing environmental pollution in urban areas has been endangering the survival of carbonate stones in monuments and statuary for many decades. Numerous conservation treatments have been applied for the protection and consolidation of these works of art. Most of them, however, either release dangerous gases during curing or show very little efficacy. Bacterially induced carbonate mineralization has been proposed as a novel and environmentally friendly strategy for the conservation of deteriorated ornamental stone. However, the method appeared to display insufficient consolidation and plugging of pores. Here we report that Myxococcus xanthus-induced calcium carbonate precipitation efficiently protects and consolidates porous ornamental limestone. The newly formed carbonate cements calcite grains by depositing on the walls of the pores without plugging them. Sonication tests demonstrate that these new carbonate crystals are strongly attached to the substratum, mostly due to epitaxial growth on preexisting calcite grains. The new crystals are more stress resistant than the calcite grains of the original stone because they are organic-inorganic composites. Variations in the phosphate concentrations of the culture medium lead to changes in local pH and bacterial productivity. These affect the structure of the new cement and the type of precipitated CaCO3 pollymorph (vaterite or calcite). The manipulation of culture medium composition creates new ways of controlling bacterial biomineralization that in the future could be applied to the conservation of ornamental stone.