Introduction

nf-core/seqsubmit is a Nextflow pipeline for submitting metagenomic assemblies, MAGs, and bins to ENA.

The pipeline supports two workflow paths:

  • GENOMESUBMIT for --mode mags and --mode bins
  • ASSEMBLYSUBMIT for --mode metagenomic_assemblies

Before you start

Before running the pipeline, make sure that:

  • Nextflow >=25.04.0 is available.
  • You have a Webin account registered at https://www.ebi.ac.uk/ena/submit/webin/login.
  • The raw reads used to generate the submitted assemblies have already been submitted to INSDC/ENA and the relevant accessions are available.

Set your Webin credentials as Nextflow secrets:

nextflow secrets set WEBIN_ACCOUNT "Webin-XXX"
nextflow secrets set WEBIN_PASSWORD "XXX"

Samplesheet input

You will need to create a samplesheet with information about the data entries you would like to process before running the pipeline. Use --input parameter to specify its location. It has to be a comma-separated file with the structure defined by the execution --mode.

--input '[path to samplesheet.csv]'

mags and bins modes (GENOMESUBMIT)

Use this samplesheet structure for MAG and bin submission. The input format follows assets/schema_input_genome.json.

Example:

samplesheet_genomes.csv
sample,fasta,accession,fastq_1,fastq_2,assembly_software,binning_software,binning_parameters,stats_generation_software,completeness,contamination,genome_coverage,metagenome,co-assembly,broad_environment,local_environment,environmental_medium,RNA_presence,NCBI_lineage
mag_001,data/mag_001.fasta.gz,SRR24458089,,,SPAdes 3.15.5,MetaBAT2 2.15,default,CheckM2 1.0.1,92.81,1.09,66.04,sediment metagenome,No,marine,cable bacteria,marine sediment,No,d__Bacteria;p__Proteobacteria;s__
ColumnDescription
sampleUnique identifier of this particular data entry. It is used as the alias when submitting to ENA, so it must be unique within one Webin account.
fastaPath to MAG/bin contigs in FASTA format compressed with gzip.
accessionENA accession of the run or metagenomic assembly used to generate the MAG/bin.
fastq_1Path to the read file in FASTQ format used to generate the source metagenomic assembly. Required if genome_coverage is not provided.
fastq_2Path to the second read file in FASTQ format for paired-end data used to generate the source metagenomic assembly. Leave empty for single-end reads.
assembly_softwareTool name and version that were used to generate the source metagenomic assembly.
binning_softwareBinning tool, including version, that was used to generate the bins.
binning_parametersArguments that were used during binning.
stats_generation_softwareTool, including version, that was used to calculate completeness and contamination.
completenessGenome completeness value.
contaminationGenome contamination value.
genome_coverageEstimated average sequencing depth across the genome. If the value is missing, it is computed automatically during pipeline execution when reads are provided.
metagenomeRegistered metagenome taxonomic identifier or name that matches an existing ENA taxonomy entry. For more details see https://ena-docs.readthedocs.io/en/latest/faq/taxonomy.html
co-assemblyWhether a co-assembly strategy was used for the initial metagenomic assembly generation. Options: Yes or No.
broad_environmentBroad ecological context of the sample, for example ‘marine biome’, ‘desert biome’. It is recommended to use subclasses of EnvO ‘biome’ class (http://purl.obolibrary.org/obo/ENVO_00000428)
local_environmentLocal environmental context of the sample, for example ‘tropical dry broadleaf forest biome’, ‘marine abyssal zone biome’. It is recommended to use EnvO terms which are of smaller spatial grain than your entry for “broad-scale environmental context”.
environmental_mediumMaterial displaced by the sample, or the material in which the sample was embedded before sampling, for example ‘mucus’, ‘lake water’. It is recommended to use subclasses of EnvO ‘environmental material’ class (http://purl.obolibrary.org/obo/ENVO_00010483).
RNA_presencePresence or absence of the 23S, 16S, and 5S rRNA genes and at least 18 tRNAs. This is used for MISAG/MIMAG assembly quality classification. Options: Yes or No.
NCBI_lineageNCBI taxonomy lineage of the genome. Can be composted of either numerical IDs or taxon names separated by ”;”.
Note

More information about envioronment tags can be found at checklists ERC000050 for bins and ERC000047 for MAGs under the field names “broad-scale environmental context”, “local environmental context”, and “environmental medium”.

metagenomic_assemblies mode (ASSEMBLYSUBMIT)

Use this samplesheet structure for metagenomic assembly submission. The input format follows assets/schema_input_assembly.json.

Provide either read files (fastq_1, optionally fastq_2) or a coverage value for each row. If coverage is missing and reads are provided, the workflow calculates average coverage automatically.

Example:

samplesheet_assembly.csv
sample,fasta,fastq_1,fastq_2,coverage,run_accession,assembler,assembler_version
assembly_001,data/assembly_001.fasta.gz,data/assembly_001_R1.fastq.gz,data/assembly_001_R2.fastq.gz,,ERR011322,SPAdes,3.15.5
assembly_002,data/assembly_002.fasta.gz,,,42.7,ERR011323,MEGAHIT,1.2.9
ColumnDescription
sampleUnique identifier of this particular data entry. It is used as the alias when submitting to ENA, so it must be unique within one Webin account.
fastaPath to assembly contigs in FASTA format compressed with gzip.
fastq_1Path to the read file in FASTQ format used to generate the metagenomic assembly. Required if coverage is not provided.
fastq_2Path to the second read file in FASTQ format for paired-end data used to generate the source metagenomic assembly. Leave empty for single-end reads.
coverageEstimated sequencing depth of the assembly. If this value is missing, it is computed automatically during pipeline execution when reads are provided.
run_accessionENA run accession for the reads used to generate the metagenomic assembly. Reads must already be submitted to ENA.
assemblerName of the assembler software used to generate the assembly.
assembler_versionVersion of the assembler software used to generate the assembly.

An example file is available at assets/samplesheet_assembly.csv.

Running the pipeline

General command template:

nextflow run nf-core/seqsubmit \
    -profile <docker/singularity/...> \
    --mode <mags|bins|metagenomic_assemblies> \
    --input <samplesheet.csv> \
    --centre_name <your_centre> \
    --submission_study <your_study> \
    --outdir <outdir>

Key parameters:

ParameterDescription
--modeSubmission type. Supported values are mags, bins, and metagenomic_assemblies.
--inputPath to the samplesheet describing the data to submit.
--submission_studyENA study accession (PRJ/ERP) to submit the data to. For metagenomic assemblies, this is the paper’s ENA Assembly Project accession.
--centre_nameName of the submitter’s organisation.
--test_uploadSubmit to the ENA TEST server instead of the LIVE server.
--webincli_submitIf true, submit to ENA. If false, validate the submission without uploading.
--upload_tpaMark assemblies as third party assemblies when required.

Validation example for mags run with docker:

nextflow run nf-core/seqsubmit \
    -profile docker \
    --mode mags \
    --input assets/samplesheet_genomes.csv \
    --submission_study <your_study> \
    --centre_name TEST_CENTER \
    --webincli_submit true \
    --test_upload true \
    --outdir results/validate_mags

Validation example for metagenomic_assemblies run with docker:

nextflow run nf-core/seqsubmit \
    -profile docker \
    --mode metagenomic_assemblies \
    --input assets/samplesheet_assembly.csv \
    --submission_study <your_study> \
    --centre_name TEST_CENTER \
    --webincli_submit true \
    --test_upload true \
    --outdir results/validate_assemblies

If you wish to repeatedly use the same parameters for multiple runs, rather than specifying each flag in the command, you can specify these in a params file.

Pipeline settings can be provided in a yaml or json file via -params-file <file>.

Warning

Do not use -c <file> to specify parameters as this will result in errors. Custom config files specified with -c must only be used for tuning process resource specifications, other infrastructural tweaks (such as output directories), or module arguments (args).

The above pipeline run specified with a params file in yaml format:

nextflow run nf-core/seqsubmit -profile docker -params-file params.yaml

with:

params.yaml
input: './samplesheet.csv'
outdir: './results/'
<...>

You can also generate such YAML/JSON files via nf-core/launch.

Updating the pipeline

When you run the above command, Nextflow automatically pulls the pipeline code from GitHub and stores it as a cached version. When running the pipeline after this, it will always use the cached version if available - even if the pipeline has been updated since. To make sure that you’re running the latest version of the pipeline, make sure that you regularly update the cached version of the pipeline:

nextflow pull nf-core/seqsubmit

Reproducibility

It is a good idea to specify the pipeline version when running the pipeline on your data. This ensures that a specific version of the pipeline code and software are used when you run your pipeline. If you keep using the same tag, you’ll be running the same version of the pipeline, even if there have been changes to the code since.

First, go to the nf-core/seqsubmit releases page and find the latest pipeline version - numeric only (eg. 1.3.1). Then specify this when running the pipeline with -r (one hyphen) - eg. -r 1.3.1. Of course, you can switch to another version by changing the number after the -r flag.

This version number will be logged in reports when you run the pipeline, so that you’ll know what you used when you look back in the future. For example, at the bottom of the MultiQC reports.

To further assist in reproducibility, you can use share and reuse parameter files to repeat pipeline runs with the same settings without having to write out a command with every single parameter.

Tip

If you wish to share such profile (such as upload as supplementary material for academic publications), make sure to NOT include cluster specific paths to files, nor institutional specific profiles.

Core Nextflow arguments

Note

These options are part of Nextflow and use a single hyphen (pipeline parameters use a double-hyphen)

-profile

Use this parameter to choose a configuration profile. Profiles can give configuration presets for different compute environments.

Several generic profiles are bundled with the pipeline which instruct the pipeline to use software packaged using different methods (Docker, Singularity, Podman, Shifter, Charliecloud, Apptainer, Conda) - see below.

Important

We highly recommend the use of Docker or Singularity containers for full pipeline reproducibility, however when this is not possible, Conda is also supported.

The pipeline also dynamically loads configurations from https://github.com/nf-core/configs when it runs, making multiple config profiles for various institutional clusters available at run time. For more information and to check if your system is supported, please see the nf-core/configs documentation.

Note that multiple profiles can be loaded, for example: -profile test,docker - the order of arguments is important! They are loaded in sequence, so later profiles can overwrite earlier profiles.

If -profile is not specified, the pipeline will run locally and expect all software to be installed and available on the PATH. This is not recommended, since it can lead to different results on different machines dependent on the computer environment.

  • test
    • A profile with a complete configuration for automated testing
    • Includes links to test data so needs no other parameters
  • docker
    • A generic configuration profile to be used with Docker
  • singularity
    • A generic configuration profile to be used with Singularity
  • podman
    • A generic configuration profile to be used with Podman
  • shifter
    • A generic configuration profile to be used with Shifter
  • charliecloud
    • A generic configuration profile to be used with Charliecloud
  • apptainer
    • A generic configuration profile to be used with Apptainer
  • wave
    • A generic configuration profile to enable Wave containers. Use together with one of the above (requires Nextflow 24.03.0-edge or later).
  • conda
    • A generic configuration profile to be used with Conda. Please only use Conda as a last resort i.e. when it’s not possible to run the pipeline with Docker, Singularity, Podman, Shifter, Charliecloud, or Apptainer.

-resume

Specify this when restarting a pipeline. Nextflow will use cached results from any pipeline steps where the inputs are the same, continuing from where it got to previously. For input to be considered the same, not only the names must be identical but the files’ contents as well. For more info about this parameter, see this blog post.

You can also supply a run name to resume a specific run: -resume [run-name]. Use the nextflow log command to show previous run names.

-c

Specify the path to a specific config file (this is a core Nextflow command). See the nf-core website documentation for more information.

Custom configuration

Resource requests

Whilst the default requirements set within the pipeline will hopefully work for most people and with most input data, you may find that you want to customise the compute resources that the pipeline requests. Each step in the pipeline has a default set of requirements for number of CPUs, memory and time. For most of the pipeline steps, if the job exits with any of the error codes specified here it will automatically be resubmitted with higher resources request (2 x original, then 3 x original). If it still fails after the third attempt then the pipeline execution is stopped.

To change the resource requests, please see the max resources and tuning workflow resources section of the nf-core website.

Custom Containers

In some cases, you may wish to change the container or conda environment used by a pipeline steps for a particular tool. By default, nf-core pipelines use containers and software from the biocontainers or bioconda projects. However, in some cases the pipeline specified version maybe out of date.

To use a different container from the default container or conda environment specified in a pipeline, please see the updating tool versions section of the nf-core website.

Custom Tool Arguments

A pipeline might not always support every possible argument or option of a particular tool used in pipeline. Fortunately, nf-core pipelines provide some freedom to users to insert additional parameters that the pipeline does not include by default.

To learn how to provide additional arguments to a particular tool of the pipeline, please see the customising tool arguments section of the nf-core website.

nf-core/configs

In most cases, you will only need to create a custom config as a one-off but if you and others within your organisation are likely to be running nf-core pipelines regularly and need to use the same settings regularly it may be a good idea to request that your custom config file is uploaded to the nf-core/configs git repository. Before you do this please can you test that the config file works with your pipeline of choice using the -c parameter. You can then create a pull request to the nf-core/configs repository with the addition of your config file, associated documentation file (see examples in nf-core/configs/docs), and amending nfcore_custom.config to include your custom profile.

See the main Nextflow documentation for more information about creating your own configuration files.

If you have any questions or issues please send us a message on Slack on the #configs channel.

Running in the background

Nextflow handles job submissions and supervises the running jobs. The Nextflow process must run until the pipeline is finished.

The Nextflow -bg flag launches Nextflow in the background, detached from your terminal so that the workflow does not stop if you log out of your session. The logs are saved to a file.

Alternatively, you can use screen / tmux or similar tool to create a detached session which you can log back into at a later time. Some HPC setups also allow you to run nextflow within a cluster job submitted your job scheduler (from where it submits more jobs).

Nextflow memory requirements

In some cases, the Nextflow Java virtual machines can start to request a large amount of memory. We recommend adding the following line to your environment to limit this (typically in ~/.bashrc or ~./bash_profile):

NXF_OPTS='-Xms1g -Xmx4g'