SRX1743310 Ecology Glacier cryoconite holes GLECr5 Ecology Glacier cryoconite hole sediment metagenome, V3-V4 regions of the 16S rRNA bacterial gene SRP074409 SUB950779 SRS1422531 SUB1486241 AMPLICON METAGENOMIC PCR 600 0 Application Read Forward 1 1 Application Read Reverse 301 Illumina MiSeq