Abstract
Caves are semi-closed ecosystems that experience the absence of sunlight and often, poor organic matter conditions due to physical isolation. Therefore, microbial activity is a crucial factor for sustaining life in caves. However, the heterogeneity of microbial diversity and community structure in relation to different types of habitats in karstic caves (e.g., drip water residue, mineral deposits, rock varnish) remains largely unknown. In this study, cave deposit samples in various morphology were analyzed to reveal its bacterial and archaeal diversity of İnsuyu Cave in Burdur Province that is located in central Turkey. Illumina MiSeq sequencing of seven cave deposit samples (S1–S7) from the zones with a diverse array of environmental conditions revealed a total of four bacterial phyla including (1) Proteobacteria ranging from 80.20% to 98.72%, (2) Actinobacteria ranging from 0.23–13.03%, (3) Firmicutes ranging from 0.18 to 12.61% and (4) Bacteroidetes ranging from 0.00% to 3.80%, while none of the samples exhibits sign for archaeal life form. The heatmap diagram on abundance and distribution of the genera, referring to the results of 16S rRNA gene-based metagenomic analysis of the cave-dwelling microbial communities in İnsuyu Cave, revealed that the structures of the bacterial communities were significantly different across the samples (S1–S7). The high abundance of taxa that is relevant to anthropogenic activity revealed a strong impact of agricultural activity on the bacterial composition of İnsuyu Cave.
Original language | English |
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Pages (from-to) | 776-790 |
Number of pages | 15 |
Journal | Geomicrobiology Journal |
Volume | 38 |
Issue number | 9 |
DOIs | |
Publication status | Published - 2021 |
Bibliographical note
Publisher Copyright:© 2021 Informa UK Limited, trading as Taylor & Francis Group.
Funding
This study was funded by Scientific Research Projects Division of Istanbul Technical University (ITU BAP) Project Number [TDK-2019-42421] (Microclimate, geochemistry and microbiologic characteristics of cave environments). We would like to thank Dr. Selim Erdoğan and The Department of Cave Protection of TC Agriculture and Forestry Municipality for permission and support in the study site. We also specially thank Ali Yamaç and Obruk Cave Research Association (O’mag, Turkey) for their assistance and priceless effort during mapping and sampling procedures within the 5-year expedition of İnsuyu Cave. We are also grateful to Dr. Alper Tunga Akarsubaşı, Dr. Halil Kurt and the team for their technical support and guidance during phylogenetic analysis. We also thank Mehmet Baki Yokeş and Mustafa Kolukırık for technical support in bioinformatics and statistical analysis following metagenomic analysis.
Funders | Funder number |
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Department of Cave Protection of TC Agriculture and Forestry Municipality | |
Obruk Cave Research Association | |
Istanbul Teknik Üniversitesi | |
Bilimsel Araştırma Projeleri Birimi, İstanbul Teknik Üniversitesi | TDK-2019-42421 |
Keywords
- Anthropogenic impact
- biodiversity
- cave deposits
- groundwater
- subsurface microbiology