Tomczyk-Żak Karolina, Szczesny Paweł, Gromadka Robert, Zielenkiewicz Urszula
Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, PAS, Warsaw, Poland.
Faculty of Biology, Institute of Experimental Plant Biology and Biotechnology, University of Warsaw, Warsaw, Poland.
PeerJ. 2017 Aug 15;5:e3635. doi: 10.7717/peerj.3635. eCollection 2017.
An exceptionally thick biofilm covers walls of ancient gold and arsenic Złoty Stok mine (Poland) in the apparent absence of organic sources of energy.
We have characterized this microbial community using culture-dependent and independent methods. We sequenced amplicons of the 16S rRNA gene obtained using generic primers and additional primers targeted at Archaea and Actinobacteria separately. Also, we have cultured numerous isolates from the biofilm on different media under aerobic and anaerobic conditions. We discovered very high biodiversity, and no single taxonomic group was dominant. The majority of almost 4,000 OTUs were classified above genus level indicating presence of novel species. Elemental analysis, performed using SEM-EDS and X-ray, of biofilm samples showed that carbon, sulphur and oxygen were not evenly distributed in the biofilm and that their presence is highly correlated. However, the distribution of arsenic and iron was more flat, and numerous intrusions of elemental silver and platinum were noted, indicating that microorganisms play a key role in releasing these elements from the rock.
Altogether, the picture obtained throughout this study shows a very rich, complex and interdependent system of rock biofilm. The chemical heterogeneity of biofilm is a likely explanation as to why this oligotrophic environment is capable of supporting such high microbial diversity.
在明显缺乏有机能源的情况下，波兰古老的佐洛托斯托克金砷矿的矿壁上覆盖着一层异常厚实的生物膜。
我们运用依赖培养和不依赖培养的方法对这个微生物群落进行了表征。我们对使用通用引物以及分别针对古菌和放线菌的额外引物所获得的16S rRNA基因扩增子进行了测序。此外，我们在有氧和厌氧条件下，在不同培养基上培养了从生物膜中分离出的众多菌株。我们发现生物多样性非常高，没有单一的分类群占主导地位。近4000个操作分类单元中的大多数在属水平以上被分类，这表明存在新物种。使用扫描电子显微镜 - 能谱仪（SEM - EDS）和X射线对生物膜样本进行的元素分析表明，碳、硫和氧在生物膜中分布不均，且它们的存在高度相关。然而，砷和铁的分布更为均匀，并且注意到有大量元素银和铂的侵入，这表明微生物在从岩石中释放这些元素方面起着关键作用。
总体而言，整个这项研究获得的情况显示出一个非常丰富、复杂且相互依存的岩石生物膜系统。生物膜的化学异质性可能解释了为什么这个贫营养环境能够支持如此高的微生物多样性。
