Biowulf High Performance Computing at the NIH
metaphlan on Biowulf

From the metaphlan documentation:

MetaPhlAn is a computational tool for profiling the composition of microbial communities (Bacteria, Archaea and Eukaryotes) from metagenomic shotgun sequencing data (i.e. not 16S) with species-level. With the newly added StrainPhlAn module, it is now possible to perform accurate strain-level microbial profiling. MetaPhlAn relies on ~1.1M unique clade-specific marker genes identified from ~100,000 reference genomes (~99,500 bacterial and archaeal and ~500 eukaryotic), allowing:
  • unambiguous taxonomic assignments;
  • accurate estimation of organismal relative abundance;
  • species-level resolution for bacteria, archaea, eukaryotes and viruses;
  • strain identification and tracking;
  • orders of magnitude speedups compared to existing methods;
  • metagenomic strain-level population genomics

Metaphlan versions >3 include strainphlan, phylophlan, and hclust2.


  • D. Tin Truong, E. A. Franzosa, T. L. Tickle, M. Scholz, G. Weingart, E. Pasolli, A. Tett, C. Huttenhower and N. Segata. MetaPhlAn2 for enhanced metagenomic taxonomic profiling. Nat Methods. 13:101 (2016). PubMed |  Journal
  • D. Tin Truong, A. Tett, E. Pasolli, C. Huttenhower, and N. Segata. Microbial strain-level population structure and genetic diversity from metagenomes. Genome Res. 27:626-638 (2017) PubMed |  PMC |  Journal
Important Notes

Interactive job
Interactive jobs should be used for debugging, graphics, or applications that cannot be run as batch jobs.

Allocate an interactive session and run the program. Sample session:

[user@biowulf]$ sinteractive -c4 --mem=8g --gres=lscratch:10
salloc.exe: Pending job allocation 46116226
salloc.exe: job 46116226 queued and waiting for resources
salloc.exe: job 46116226 has been allocated resources
salloc.exe: Granted job allocation 46116226
salloc.exe: Waiting for resource configuration
salloc.exe: Nodes cn3144 are ready for job

[user@cn3144]$ cd /lscratch/$SLURM_JOB_ID

[user@cn3144]$ module load metaphlan

[user@cn3144]$ export METAPHLAN_DB=/data/$USER/mp_db

[user@cn3144]$ mkdir fasta

[user@cn3144]$ cp ${METAPHLAN_TEST_DATA:-none}/*.fasta.gz fasta

[user@cn3144]$ ls -lh fasta
-rw-r--r-- 1 user group 690K Nov  4 13:11 SRS014459-Stool.fasta.gz
-rw-r--r-- 1 user group 608K Nov  4 13:11 SRS014464-Anterior_nares.fasta.gz
-rw-r--r-- 1 user group 704K Nov  4 13:11 SRS014470-Tongue_dorsum.fasta.gz
-rw-r--r-- 1 user group 748K Nov  4 13:11 SRS014472-Buccal_mucosa.fasta.gz
-rw-r--r-- 1 user group 696K Nov  4 13:11 SRS014476-Supragingival_plaque.fasta.gz
-rw-r--r-- 1 user group 687K Nov  4 13:11 SRS014494-Posterior_fornix.fasta.gz

[user@cn3144]$ for f in fasta/*.gz
do name=$(basename $f .fasta.gz)
   metaphlan --nproc $SLURM_CPUS_PER_TASK --bowtie2out ${name}.bt2.bz2 \
             --input_type fasta --bowtie2db $METAPHLAN_DB $f > ${name}_profile.txt

[user@cn3144]$ *_profile.txt > merged_abundance_table.txt

[user@cn3144]$ exit
salloc.exe: Relinquishing job allocation 46116226


Batch job
Most jobs should be run as batch jobs.

Create a batch input file (e.g. For example:

module load metaphlan || exit 1
name=$(dirname $fastq)/$(basename $fastq .fastq.gz)
metaphlan --nproc $SLURM_CPUS_PER_TASK --bowtie2out ${name}.bt2.bz2 \
          --input_type fastq --bowtie2db $METAPHLAN_DB $fastq > ${name}_profile.txt

Submit this job using the Slurm sbatch command.

sbatch --cpus-per-task=6 --mem=12g
Swarm of Jobs
A swarm of jobs is an easy way to submit a set of independent commands requiring identical resources.

Create a swarmfile (e.g. metaphlan.swarm). For example:

metaphlan --nproc $SLURM_CPUS_PER_TASK --bowtie2out sample1.bt2.bz2 \
          --input_type fastq --bowtie2db $METAPHLAN_DB sample1.fastq.gz > sample1_profile.txt
metaphlan --nproc $SLURM_CPUS_PER_TASK --bowtie2out sample2.bt2.bz2 \
          --input_type fastq --bowtie2db $METAPHLAN_DB sample2.fastq.gz > sample2_profile.txt
metaphlan --nproc $SLURM_CPUS_PER_TASK --bowtie2out sample3.bt2.bz2 \
          --input_type fastq --bowtie2db $METAPHLAN_DB sample3.fastq.gz > sample3_profile.txt

Submit this job using the swarm command.

swarm -f metaphlan.swarm -g 12 -t 6 --module metaphlan
-g # Number of Gigabytes of memory required for each process (1 line in the swarm command file)
-t # Number of threads/CPUs required for each process (1 line in the swarm command file).
--module metaphlan Loads the metaphlan module for each subjob in the swarm