Protein-level assembly increases protein sequence recovery from metagenomic samples manyfold

The open-source de - novo Protein-level assembler Plass ( https://plass.mmseqs.org ) assembles six-frame-translated sequencing reads into protein sequences. It recovers 2 to 10 times more protein sequences from complex metagenomes and can assemble huge datasets. We assembled two redundancy-filtered reference protein catalogs, 2 billion sequences from 640 soil samples (SRC) and 292 million sequences from 775 marine eukaryotic metatranscriptomes (MERC), the largest free collections of protein sequences.