sliva rRNA数据库（http://www.arb-silva.de/）用来检查和比对RNA序列，既可以针对16S/18S,SSU，也可以针对23S/28S, LSU，包括了Bacteria, Archaea and Eukarya。同时也是ARB的官方指定数据库。

LSU: Large subunit (23S/28Sribosomal RNAs) 大亚基
细菌、古菌16S rRNA
SSU: Small subunit (16S/18Sribosomal RNAs) 小亚基
真菌28S rRNA

仅仅是下载fasta文件

下载地址：http://www.arb-silva.de/no_cache/download/archive/release_119/Exports/

根据下载的需求，选择针对23S/28Sribosomal RNAs的LSU或者是针对16S/18Sribosomal RNAs的SSU；然后选择是否去冗余的，我选择去，即Nr99;然后选择是否trunc，即是否对名字缩写；选择是否全长比对结果；

*_tax_silva.fasta.gz

---

Multi FASTA files of the SSU/LSU databases including the SILVAtaxonomy for

Bacteria, Archaea and Eukaryotes in the header.

REMARK: The sequences in the files are NOT truncated to theeffective LSU or

SSU genes. They contain the full entries as they have been depositedin the

public repositories (ENA/GenBank/DDBJ).

Fasta header:

accession_number.start_position.stop_position taxonomic pathorganism name

*_tax_silva_full_align_trunc.fasta.gz

---

Multi FASTA files of the SSU/LSU databases including the SILVAtaxonomy for

Bacteria, Archaea and Eukaryotes in the header (including the FULLalignment).

REMARK: Sequences in these files haven been truncated. This meansthat all

nucleotides that have not been aligned were removed from thesequence.

*_tax_silva_trunc.fasta.gz

---

Multi FASTA files of the SSU/LSU database including the SILVAtaxonomy for

Bacteria, Archaea and Eukaryotes in the header.

REMARK: Sequences in these files haven been truncated. This meansthat all

nucleotides that have not been aligned were removed from thesequence.

生成使用与Mothur的silva数据库：http://blog.mothur.org/2014/08/08/SILVA-v119-reference-files/

参考

https://www.cnblogs.com/nkwy2012/p/6396427.html#:~:text=%E4%B8%8B%E8%BD%BD%E5%9C%B0%E5%9D%80%EF%BC%9Ahttp%3A%2F%2Fwww.arb-silva.de%2Fno_cache%2Fdownload%2Farchive%2Frelease_119%2FExports%2F%20%E6%A0%B9%E6%8D%AE%E4%B8%8B%E8%BD%BD%E7%9A%84%E9%9C%80%E6%B1%82%EF%BC%8C%E9%80%89%E6%8B%A9%E9%92%88%E5%AF%B923S%2F28Sribosomal,RNAs%E7%9A%84LSU%E6%88%96%E8%80%85%E6%98%AF%E9%92%88%E5%AF%B916S%2F18Sribosomal%20RNAs%E7%9A%84SSU%EF%BC%9B%E7%84%B6%E5%90%8E%E9%80%89%E6%8B%A9%E6%98%AF%E5%90%A6%E5%8E%BB%E5%86%97%E4%BD%99%E7%9A%84%EF%BC%8C%E6%88%91%E9%80%89%E6%8B%A9%E5%8E%BB%EF%BC%8C%E5%8D%B3Nr99%3B%E7%84%B6%E5%90%8E%E9%80%89%E6%8B%A9%E6%98%AF%E5%90%A6trunc%EF%BC%8C%E5%8D%B3%E6%98%AF%E5%90%A6%E5%AF%B9%E5%90%8D%E5%AD%97%E7%BC%A9%E5%86%99%EF%BC%9B%E9%80%89%E6%8B%A9%E6%98%AF%E5%90%A6%E5%85%A8%E9%95%BF%E6%AF%94%E5%AF%B9%E7%BB%93%E6%9E%9C%EF%BC%9B