SILVA Release 111: Download the latest SILVA databases for ARB for small (16S/18S) and large (23S/28S) subunit ribosomal RNAs.

SSU	Ref		445 MB		This is the reference database containing only high quality, aligned 16S/18S ribosomal RNA sequences with a minimum length of 1200 bases for Bacteria and Eukarya and 900 bases for Archaea. A fully classified guide tree is included for fast navigation. For details see release information
	HSM/MWM/ GNHM		306 MB		This file contains only high quality sequences from the Human Skin Microbiome, the Mouse Wound Microbiota and the Guerrero Negro hypersaline microbial mat (all not included in SSURef).
	Ref NR		230 MB		This dataset is based on the full Ref 111 and HSM/MWM/GNHM datasets with a 98% criterion applied to remove redundant sequences using the UCLUST tool. Sequences from cultivated species have been preserved independent from prior filtering. The final dataset contains 286,858 sequences and can be used as a representative dataset for phylogenetic analysis and classification. More information ...
	Parc		2 GB		This is the comprehensive 16S/18S database with all aligned, quality checked rRNA sequences longer than 300 bases. No tree included, selection of groups can be done based on the EMBL taxonomy.
LSU	Ref		27  MB		This is the reference database containing only high quality, aligned 23S/28S ribosomal RNA sequences with a minimum length of 1900 bases. A fully classified guide tree is included for fast navigation. For details see release information
	Parc		180  MB		This is the comprehensive 23S/28S database with all aligned, quality checked rRNA sequences longer than 300 bases.

FASTA exports can be found in the file archive

All files can also be accessed via our FTP-server ftp.arb-silva.de

All files for downloading are compressed by tar and gzip. For unpacking use the tar -xzvf <filename> command under Linux or winrar under Windows. Please also check if you have sufficient main memory (RAM) available to handle the databases (see box below) and make sure that you have the latest version of ARB installed on your computer.

ARB is a so-called "in-memory" database and the larger the databases are, the more main memory (RAM) is required by ARB to handle them. This is by far the most important aspect you have to consider when asking for ARB hardware requirements!

The following table will help you to find out more about the ARB hardware requirements for the SILVA rRNA databases listed above:

ARB/SILVA Memory Requirements v1.3 (pdf, 34 kb).

Users from non-academic/commercial environments should have a look at the SILVA Terms of Use/License Information