Andrei Adrian-Ştefan, Păuşan Manuela R, Tămaş Tudor, Har Nicolae, Barbu-Tudoran Lucian, Leopold Nicolae, Banciu Horia L
Department of Molecular Biology and Biotechnology, Babeş-Bolyai UniversityCluj-Napoca, Romania; Institute of Hydrobiology, Department of Aquatic Microbial Ecology, Biology Center of the Academy of Sciences of the Czech RepublicČeské Budějovice, Czechia.
Department of Molecular Biology and Biotechnology, Babeş-Bolyai UniversityCluj-Napoca, Romania; Department for Internal Medicine, Medical University of GrazGraz, Austria.
Front Microbiol. 2017 Mar 7;8:372. doi: 10.3389/fmicb.2017.00372. eCollection 2017.
In this study, we investigated the biomineralization potential and diversity of the epilithic bacterial communities dwelling on the limestone statue of Saint Donatus, the oldest public monument of Cluj-Napoca city (Transylvania region, NW Romania). Their spatial distribution together with phylogenetic and metabolic diversity, as well as their capacity to precipitate calcium carbonate was evaluated by combining molecular and phenotypic fingerprinting methods with X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron-microscopy analyses. The results of real-time quantitative PCR, molecular fingerprinting and community-level physiological profiling showed that diverse and abundant bacterial assemblages that differ in relation to their collection site colonized the statue. The cultivation and molecular identification procedures allowed the characterization of 79 bacterial isolates belonging to Proteobacteria (73.4%), Firmicutes (19%), and Actinobacteria (7.6%). Amongst them, the 22 strains identified as being capable of calcium carbonate precipitation were found to belong mostly to and genera. We found that bacteria acted as nucleation sites, inducing the formation of nanoscale aggregates that were shown to be principally composed of vaterite. Furthermore, we expanded the current knowledge on culturable diversity of carbonatogenic bacteria by providing evidence for biogenic vaterite/calcite formation mediated by: , , , , and . Overall, this study highlights the need to evaluate the carbonatogenetic potential of all the bacterial communities present on stone artwork prior to designing an efficient conservation treatment based on biomineralization.
在本研究中，我们调查了居住在克卢日-纳波卡市（罗马尼亚西北部特兰西瓦尼亚地区）最古老的公共纪念碑——圣多纳图斯石灰岩雕像上的附石细菌群落的生物矿化潜力和多样性。通过将分子和表型指纹图谱方法与X射线衍射、傅里叶变换红外光谱和扫描电子显微镜分析相结合，评估了它们的空间分布以及系统发育和代谢多样性，以及它们沉淀碳酸钙的能力。实时定量PCR、分子指纹图谱和群落水平生理分析的结果表明，不同且丰富的细菌群落根据其采集地点而有所不同，它们在雕像上定殖。培养和分子鉴定程序使我们能够鉴定出79株细菌分离株，分别属于变形菌门（73.4%）、厚壁菌门（19%）和放线菌门（7.6%）。其中，被鉴定为能够沉淀碳酸钙的22株菌株大多属于 属和 属。我们发现细菌充当了成核位点，诱导形成了纳米级聚集体，这些聚集体主要由球霰石组成。此外，我们通过提供由 、 、 、 和 介导的生物成因球霰石/方解石形成的证据，扩展了目前关于产碳酸细菌可培养多样性的知识。总体而言，本研究强调在设计基于生物矿化的高效保护处理方法之前，需要评估存在于石雕艺术品上的所有细菌群落的碳生成潜力。
