The Biological Observation Matrix (BIOM) format¶

The BIOM file format (canonically pronounced biome) is designed to be a general-use format for representing biological sample by observation contingency tables. BIOM is a recognized standard for the Earth Microbiome Project and is a Genomics Standards Consortium candidate project.

The BIOM format is designed for general use in broad areas of comparative -omics. For example, in marker-gene surveys, the primary use of this format is to represent OTU tables: the observations in this case are OTUs and the matrix contains counts corresponding to the number of times each OTU is observed in each sample. With respect to metagenome data, this format would be used to represent metagenome tables: the observations in this case might correspond to SEED subsystems, and the matrix would contain counts corresponding to the number of times each subsystem is observed in each metagenome. Similarly, with respect to genome data, this format may be used to represent a set of genomes: the observations in this case again might correspond to SEED subsystems, and the counts would correspond to the number of times each subsystem is observed in each genome.

There are two components to the BIOM project: first is definition of the BIOM format, and second is development of support objects in multiple programming languages to support the use of BIOM in diverse bioinformatics applications. The version of the BIOM file format is independent of the version of the biom-format software.

Contents¶

BIOM version¶

The latest official version of the biom-format project is 1.1.0 and of the BIOM file format is 1.0. Details on the file format can be found here.

Installing the biom-format project¶

To install the biom-format project, you can download the release version biom-format-1.1.0, or work with the development version. Generally we recommend working with the release version as it will be more stable, but if you want access to the latest features (and can tolerate some instability) you should work with the development version.

The biom-format project has the following dependencies:

• Python 2 (2.6 or later)
• numpy (1.3.0 or later)
• gcc >= 4.1.2 (optional; used for more efficient sparse table representations)
• cython >= 0.14.1 (optional; used for more efficient sparse table representations)

We’ll illustrate the install process in the $HOME/code directory. You can either work in this directory on your system (creating it, if necessary, by running mkdir $HOME/code) or replace all occurrences of $HOME/code in the following instructions with your working directory. Change to this directory to start the install process:

cd $HOME/code

To install the release version, download from biom-format-1.1.0, uncompress the file, and change to the resulting directory:

wget ftp://thebeast.colorado.edu/pub/biom-format-releases/biom-format-1.1.0.tar.gz
tar -xvzf biom-format-1.1.0.tar.gz
cd $HOME/code/biom-format-1.1.0

Alternatively, to install the development version, pull it from github, and change to the resulting directory:

git clone git://github.com/biom-format/biom-format.git
cd $HOME/code/biom-format

To install (either the development or release version), follow these steps:

sudo python setup.py install

If you do not have sudo access on your system (or don’t want to install the biom-format project in the default location) you’ll need to install the library code and scripts in specified directories, and then tell your system where to look for those files. You can do this as follows:

echo "export PATH=$HOME/bin/:$PATH" >> $HOME/.bashrc
echo "export PYTHONPATH=$HOME/lib/:$PYTHONPATH" >> $HOME/.bashrc
mkdir -p $HOME/bin $HOME/lib/
source $HOME/.bashrc
python setup.py install --install-scripts=$HOME/bin/ --install-purelib=$HOME/lib/ --install-lib=$HOME/lib/

You should then have access to the biom-format project. You can test this by running the following command:

python -c "from biom import __version__; print __version__"

You should see the current version of the biom-format project.

Next you can run:

which convert_biom.py

You should get a file path ending with convert_biom.py printed to your screen if it is installed correctly.

Citing the BIOM project¶

You can cite the BIOM format as follows:

Development team¶

The biom-format project was conceived of and developed by the QIIME, MG-RAST, and VAMPS development groups to support interoperability of our software packages. If you have questions about the biom-format project you can contact gregcaporaso@gmail.com.