Reference dsrAB tree for taxonomic affiliation of environmental sequences

A reference dsrAB protein sequences database for taxonomic affiliation was prepared ("REFERENCES PROTEIN ALIGNMENT.aln"), updating the dataset previously published by Müller et al. (2015). The database accounted frt 1313 records with taxonomic affiliation manually curated, considering the recently updated nomenclature for 42 phyla of bacteria and archaea (Oren and Garrity 2021). The dataset was used to infer a reference tree ("Reference tree with taxonomy coloured.treefile") for phylogenetic affiliation of the NGS data. Environmental sequences were processed with Mothur v.1.44.1 (Kozich et al. 2013) software using the command batch provided as "mothur.batch". Finally, representatives of sequences clustered at 0.05 cutoff were translated into protein sequences in MEGA v.5.2 and aligned to the dsrAB reference proteins dataset in MAFFT using the auto-option ("PROTEIN_REF_AND_OTU_ALIGNED ordered.fas").