Desulfonation of biotransformation products from commercial linear alkylbenzenesulfonates

Earlier work shows that the biodegradation and biotransformation of commercial linear alkylbenzenesulfonate (LAS) as a carbon source for growth leads to a residue of sulfonated aromatic compounds, termed refractory organic carbon, from the synthetic by-products. We now show that this refractory organic carbon, after separation from sulfate ion, is utilized extensively as a sulfur source for bacterial growth. The products of desulfonation are expected to be biodegradable, so we question the value of adjectives like refractory.