A specialty chemical was used in an industrial production process until ~ 1985 when it was deemed to be a suspected carcinogen. Over the 25+ years since, the chemical company had not found the chemical to biodegrade under all tested conditions. The chemical is present in groundwater at both an active chemical production facility (RCRA) and at a Superfund site where the company is an RP.
I first heard of the problem in 2010; believing certain bacteria could degrade the chemical, I contacted an academic colleague working with those bacteria. A postdoc isolated 2 cultures that could grow on the compound as their sole carbon and energy source. Growth yields implied the compound had been degraded completely to CO2 and biomass and a provisional patent was issued.
The discovery was timely as the ground water extraction and treatment system at the RCRA site was to be upgraded in the near future, and the ROD at the Superfund site had been changed from a $32M pump and treat remedy to a $8M biological treatment remedy.