A glimpse into the genetic basis of symbiosis between and their helper strains in the biodegradation of 4-aminobenzenesulfonate.

We report the whole genome sequences of S1 and S2, the first reported bacterial co-culture capable of degrading 4-aminobenzenesulfonate (4-ABS), a recalcitrant industrial waste product. To gain insights into the genetic basis for the syntrophic interaction between this symbiotic pair and also another recently reported associated co-culture, sp. PBC and sp. PBA, we performed detailed genetic analysis of these four strains focusing on the metabolic pathways associated with biotin, -aminobenzoic acid (p), and protocatechuate metabolism. Both assembled draft genomes are missing a majority of the genetic components associated in the biosynthetic pathway of p and biotin. Interestingly, a fused p synthase was found in sp PBA but not in S2. Furthermore, using whole genome data, the taxonomic classification of sp. PBA and S2 (both previously inferred from 16S rRNA gene) was re-investigated, providing new evidence to propose for their re-classification at the genus and species level, respectively.