Liu Qi, He Zichen, Naganuma Takeshi, Nakai Ryosuke, Rodríguez Luz María, Carreño Rafael, Urbani Franco
Graduate School of Integrated Science for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima 739-8528, Japan.
Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, 2-17-2-1 Tsukisamu-Higashi, Toyohira, Sapporo 062-8517, Japan.
Microorganisms. 2022 Jul 11;10(7):1395. doi: 10.3390/microorganisms10071395.
The diversity of microorganisms associated with speleological sources has mainly been studied in limestone caves, while studies in silicate caves are still under development. Here, we profiled the microbial diversity of opal speleothems from a silicate cave in Guiana Highlands. Bulk DNAs were extracted from three speleothems of two types, i.e., one soft whitish mushroom-like speleothem and two hard blackish coral-like speleothems. The extracted DNAs were amplified for sequencing the V3-V4 region of the bacterial 16S rRNA gene by MiSeq. A total of 210,309 valid reads were obtained and clustered into 3184 phylotypes or operational taxonomic units (OTUs). The OTUs from the soft whitish speleothem were mostly affiliated with , (formerly, ), and with the OTUs ascribed to being found specifically in this speleothem. The OTUs from the hard blackish speleothems were similar to each other and were mostly affiliated with , and (formerly, ). These OTU compositions were generally consistent with those reported for limestone and silicate caves. The OTUs were further used to infer metabolic features by using the PICRUSt bioinformatic tool, and membrane transport and amino acid metabolism were noticeably featured. These and other featured metabolisms may influence the pH microenvironment and, consequently, the formation, weathering, and re-deposition of silicate speleothems.
与洞穴学来源相关的微生物多样性主要是在石灰岩洞穴中进行研究的，而对硅酸盐洞穴的研究仍在开展中。在此，我们对圭亚那高地一个硅酸盐洞穴中蛋白石洞穴沉积物的微生物多样性进行了剖析。从两种类型的三个洞穴沉积物中提取了总DNA，即一个柔软的白色蘑菇状洞穴沉积物和两个坚硬的黑色珊瑚状洞穴沉积物。提取的DNA经扩增后，通过MiSeq对细菌16S rRNA基因的V3 - V4区域进行测序。共获得210,309条有效读数，并聚类为3184个系统发育型或操作分类单元（OTU）。来自柔软白色洞穴沉积物的OTU大多隶属于 、 （以前为 ），以及 ，其中归属于 的OTU是在该洞穴沉积物中特有的。来自坚硬黑色洞穴沉积物的OTU彼此相似，大多隶属于 、 和 （以前为 ）。这些OTU组成总体上与石灰岩和硅酸盐洞穴报道的情况一致。通过使用PICRUSt生物信息工具，这些OTU被进一步用于推断代谢特征，膜转运和氨基酸代谢表现突出。这些以及其他有特征的代谢过程可能会影响pH微环境，进而影响硅酸盐洞穴沉积物的形成、风化和再沉积。
