The following pathway describes the metabolic breakdown of 4-Carboxy-4`-Sulfoazobenzene utilizing a bacterial strain (S5) adapted from Hydrogenophaga palleronii S1. Though it is generally thought that azo dyes are degraded only anaerobically, there have been recent reports to suggest otherwise. This is the first aerobic bacterial stain reported to utilize an azo dye as its sole source of carbon and energy ([http://www.ncbi.nlm.nih.gov/pubmed/9603860|Blumel et al., 1998]). In the first step of the pathway, the S5 strain cleaves 4-Carboxy-4`-Sulfoazobenze aerobically to 4-aminobenzoate and 4-aminobenzenesulfonate. These compounds are then degraded by previously determined metabolic pathways.