SILVA Databases for ARB
SILVA Release 138.1: Download the latest SILVA databases for ARB for small (16S/18S) and for large (23S/28S) subunit ribosomal RNAs.
Released: 27.08.2020
SSU |  Ref NR 99 | | 264 MB | This SSU dataset is now the recommended reference database. It is based on the Ref dataset with a 99% criterion applied to remove redundant sequences using the | |
| 680 MB | This SSU dataset containing all high quality, aligned 16S/18S ribosomal RNA sequences with a minimum length of 1200 bases for Bacteria and Eukarya and 900 bases for Archaea. For details see  release information | ||||
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LSU | Ref NR 99 | 64 MB | This SSU dataset is now the recommended reference database. It is based on the Ref dataset with a 99% criterion applied to remove redundant sequences using the
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| Ref |
| This is the LSU reference database containing only high quality, aligned 23S/28S ribosomal RNA sequences with a minimum length of 1900 bases. A fully classified guide |
All ARB files as well as FASTA exports can be found in the 
File Archive
All files can also be accessed via our FTP-server ftp.arb-silva.de
Unpacking the Files
ARB can now directly open .gz files. There is no need to unpack them anymore. Please make sure that you have the latest version of ARB installed on your computer.
ARB/SILVA Hardware Requirements
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.
Copyright/License Information
Users from non-academic/commercial environments should have a look at the SILVA Terms of Use/License Information