Cave metagenome
The libraries were prepared using Nextera DNA Flex library preparation kit (Illumina) following the manufacturer's user guide. The concentration of cleaned DNA was evaluated using the Qubit dsDNA HS Assay Kit (Life Technologies). 50 ng DNA was used to prepare the libraries. The samples underwent the simultaneous fragmentation and addition of adapter sequences. These adapters are utilized during a limited-cycle PCR in which unique indices were added to the sample. The libraries were pooled and diluted (to 0.6nM) and sequenced paired end for 250 cycles using the NovaSeq system (Illumina).