Contig Binning

In order to characterize microbial communities, it is key to resolve their composition, diversity and function. With recent advancements in sequencing techniques, whole metagenome shotgun sequencing is becoming standard in metagenomics. Because the output of this technique is a mixture of short DNA fragments belonging to various genomes, computational algorithms for clustering of related sequences are necessary. This approach is globally referred to as sequence binning, and it facilitates downstream analysis steps including: retrieval of metabolic and marker genes; core genome and housekeeping genes analysis; MLST, MLSA and phylogenetic analysis; rRNA and probe design; metagenome re-assembly.

There are two types of binning methods: a) taxonomy dependent and b) taxonomy independent. The first is implemented here through the Bin Pangenomes by Taxonomy tool and the second via the Bin Pangenomes by Sequence tool [Sedlar et al., 2017]. The performance of approach a) is limited to the completeness of an existing database, whereas approach b) usually suffers from a lack of precision. In order to leverage the full strength of the two approaches a combined analysis is encouraged, and we provide a template workflow QC, Assemble and Bin Pangenomes, that constructs lists of binned assembled contigs and reads via the two methodologies above and starting from raw reads (see QC, Assemble and Bin Pangenomes).