Semi-subterranean environment and soil metagenomic datasets of the Gyeongju Seokbinggo (stone ice storage) in South Korea

The Seokbinggo is an ice cellar made of stone to store ice in the 1700s. The Seokbinggo, a traditional Korean stone architecture, can keep ice collected in winter until summer because the semi-subterranean structure utilizes the natural environment, and the insulation design is effective. However, these structures and scientific designs are not used as ice storage and are easily damaged by biological contamination. We present the environmental data of the inside and the metagenomic dataset of the soil samples from the Seokbinggo. Next-generation sequencing was carried out on an Illumina MiSeq platform. The raw sequence data used for analysis is available in NCBI under the Sequence Read Archive (SRA) with BioProject No. PRJNA727939 and SRA accession Nos. SRX10976613, SRX10976614, SRX10976615, SRX10976616, SRX10976617, SRX10976618, SRX10976619, SRX10976620. Environmental data, including data from Korea Meteorological Administration, is available in the Mendeley data repository with DOI: 10.17632/2r8gpg7pxn.1.


a b s t r a c t
The Seokbinggo is an ice cellar made of stone to store ice in the 1700s. The Seokbinggo, a traditional Korean stone architecture, can keep ice collected in winter until summer because the semi-subterranean structure utilizes the natural environment, and the insulation design is effective. However, these structures and scientific designs are not used as ice storage and are easily damaged by biological contamination. We present the environmental data of the inside and the metagenomic dataset of the soil samples from the Seokbinggo. Next-generation sequencing was carried out on an Illumina MiSeq platform. The raw sequence data used for analysis is available in NCBI under the Sequence Read Archive (SRA) with BioProject No. PRJNA727939 and SRA accession Nos. SRX10976613, SRX10976614, SRX10976615, SRX10976616, SRX10976617, SRX10976618, SRX10976619, SRX10976620. Environmental data, including data from Korea Meteorological Administration, is available in the Mendeley data repository with DOI: 10.17632/2r8gpg7pxn.  Table   Subject Environmental science, Microbiology Specific subject area This data provides information on the semi-subterranean environment and soil microorganisms inside the Seokbinggo, Gyeongju city in South Korea. Type of data

Value of the Data
• This dataset is the only building in the Wolseong site that maintains its original shape and can be used as important data for site excavation. • Since it maintains its original shape among Seokbinggo in South Korea, it can be used as data for conservation research and comparison with other local Seokbinggos. • This dataset represents the taxonomic profile of microbial communities and environmental data within the semi-subterranean architecture. • This data can be used as useful basic data for researchers who study the correlation between environmental factors and microbial growth.
• It can be used as comparative research data for microbial diversity studies inside caves or tombs. • This data can also be used to study the secondary metabolites of microorganisms and their side effects.

Data Description
Located on the northern hill of Wolseong Fortress in Gyeongju city, this structure was used to store ice during the Joseon Dynasty ( Fig. 1 ). The storage facility can be entered by a descending stairway on its southern side and has three ventilation ducts installed on its arched roof ( Fig. 2 . B). This architecture was called the Seokbinggo. The existing location of Seokbinggo is built long from north to south on a sloping topography high in the south and low in the north, and when viewed from a distance, it looks like a long tomb (    We provide the real-time datasets collected from October 18, 2019, to October 21, 2020, from five points inside the Seokbinggo. These data parameters include air temperature and relative humidity. All parameters were measured at five points inside Seokbinggo using Testo data loggers with temperature and relative humidity sensors. A total of 84,693 measurements of each parameter were recorded from October 18, 2019, to October 21, 2020. 8870 data per parameter were collected at one site inside Seokbinggo, but data of location M3-L were collected only 4863. This is because moisture seeped into the vent at the top of the Seokbinggo and the measurement device located at the low position was damaged. This dataset contains temperature and relative humidity data obtained at each point inside the Seokbinggo, as well as raw data from the Gyeongju observatory of the Korea Meteorological Administration [4] . This dataset is available in Mendeley Data Repository (DOI: 10.17632/2r8gpg7pxn.1). These data were used to calculate average, maximum, and minimum values ( Table 1 ). The Seokbinggo, a traditional Korean stone heritage, can keep ice collected in winter until summer because the subterranean structure utilizes the natural environment, and the insulation design is effective. However, these structures and scientific designs are not used as ice storage and are easily damaged by biological contamination.
This article contains data on microbial communities formed in the soil of four points within the Seokbinggo. The first two soil samples (KJ. SBG.1 and 4) Table 2 shows the total number of sequencing reads and details about the metagenome analysis for each  sample. Also, Table 2 provides for the corresponding operational taxonomical unit (OTU) values and the Shannon diversity index for all taxonomical levels from kingdom to species. Data were presented as taxonomic and functional profiles, as shown in Tables 3 and 4 , respectively. The relative abundance of bacteria and Eukaryota was depicted at the phylum levels ( Fig. 3 ). The raw FASTQ files generated in this study were deposited at the NCBI SRA database under BioProject PRJNA727939.

Survey Area
The Seokbinggo is located within the Wolseong Fortress in the Gyeongju Historic Areas. Gyeongju Historic Area was designated as a World Heritage Site in 20 0 0. Gyeongju is a major city that embodies the history and culture of Silla (57 B.C. -A.D. 935), the golden age of ancient Korean civilization. Gyeongju's historic area has the famous palace site, Wolseong Fortress (Moon Fortress). Encircling the palace compounds, walls were built of stone and mud to the north, east, and west, while natural cliffs and a flowing stream formed the southern border. Stone terraces and moats were built along the northern and western borders, and a gate on the eastern border led to the Palace of the Crown Prince [2] . The study area is located on the northern border. The palace and other buildings do not remain, and excavations are underway at the palace site.

Data Acquisition and Sample Collection
This data acquisition period is from October 18, 2019, to October 21, 2020. We also applied the same period of time for the public database (data.kma.go.kr) [4] . TESTO Temperature/Relative humidity data loggers (testo 174 H and testo 175 H1, Germany) were installed on the front, middle, and rear sides in the Seokbinggo, respectively, ( Fig. 4 ). The exact location of the equipment is shown in Table 5 . The instrumental characteristics of data logger, testo 174 H, and testo 175 H1 are given in Table 6 .
Soil samples were collected from the four corners of Seokbinggo for use in NGS analysis ( Fig. 5 ). At each point, soil samples were collected from the depth of 10 cm in 50 mL containers. The bottom was lowered inward from the inlet that samples KJ.SBG.2 and KJ.SBG.3 farther from the inlet had a higher moisture content than the other samples KJ.SBG.1 and KJ.SBG.4.

Data Processing
The Excel 2016 program was used to convert the collected data into average, maximum, and minimum values. We calculated the average, maximum, and minimum values using the pivot table function of the Excel program and confirmed the temperature and relative humidity between the inside of Seokbinggo and the public database. The M3-L data were not used in the calculation due to missing data. Using the RStudio 1.2.1335 program, the temperature and humidity change according to the measurement location was shown in the boxplot chart ( Fig. 6 ).
Gene amplification and sequencing were performed by Macrogen Ltd. (Seoul, Korea), and the final results were sequenced using the Illumina MiSeq platform (Illumina Inc., San Diego, CA, USA) [5] . Forward primer 341F and reverse primer 805R for 16S rRNA amplification were used to amplify the V3-V4 region of the bacterial 16S rRNA. ITS rRNA was amplified using forward primer 3F and reverse primer 4R. Operational taxonomic unit (OTU) clustering was used in the de novo (CD-HIT) OTU picking method. Sequences were assigned to taxonomy using a classifier trained on NCBI 16S rRNA BLAST database and ITS rRNA UNITE database version 8.2 with the read matching to the Refs. [6 , 7] .

Ethics Statement
This data is NOT relevant for human projects and animal studies.

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data Availability
Semi-subterranean environment data of the Gyeongju Seokbinggo in South Korea