Microbial community analysis of relict niter-bed based on 16S rRNA and amoA genes
16S rRNA gene and ammonia monooxygenase gene subunit A (amoA) fragments were amplified by PCR with respective primer sets including adapter and barcode sequences from the relict niter-bed soil samples. All barcoded amplicons were pooled in equimolar ratio and subjected to 454 pyrosequencing on the 454 GS FLX Titanium platform. 16S rRNA primers: Univ519F CAGCMGCCGCGGTAATWC; Univ926R CCGTCAATTCMTTTRAGTT. Bacterial amoA primers: amoA-1F GGGGTTTCTACTGGTGGT; amoA-2R CCCCTCKGSAAAGCCTTCTTC.  Archaeal amoA primers: Arch amoAF STAATGGTCTGGCTTAGACG; Arch amoAR GCGGCCATCCATCTGTATG. Adapter sequence: TCAG. Used nucleotide barcodes: 16S rRNA gene for OVA1 TGATACGTCT; 16S rRNA gene for OVA2 CGAGAGATAC; 16S rRNA gene for OVA3 TCTACGTAGC; 16S rRNA gene for OVA4 ACTACTATGT; 16S rRNA gene for OVA5 AGCGTCGTCT; 16S rRNA gene for OVB2 TGACGTATGT; 16S rRNA gene for OVB3 ACAGTATATA; 16S rRNA gene for OVC1 AGTACGCTAT; 16S rRNA gene for OVC2 TACACGTGAT; bacterial amoA gene for OVA3 AGACGCACTC; bacterial amoA gene for OVA4 AGCACTGTAG; bacterial amoA gene for OVA5 ATCAGACACG; bacterial amoA gene for OVB2 CTCGCGTGTC; bacterial amoA gene for OVB3 TCTCTATGCG; bacterial amoA gene for OVC1 ATATCGCGAG; bacterial amoA gene for OVC2 CGTGTCTCTA; archaeal amoA gene for OVA1 TCACGTACTA; archaeal amoA gene for OVA2 CGTCTAGTAC; archaeal amoA gene for OVA3 TGTACTACTC; archaeal amoA gene for OVA4 CGTAGACTAG; archaeal amoA gene for OVA5 TACGAGTATG; archaeal amoA gene for OVB2 TCGTCGCTCG; archaeal amoA gene for OVB3 ACATACGCGT; archaeal amoA gene for OVC1 TACTCTCGTG; archaeal amoA gene for OVC2 TAGAGACGAG.