Chlorophenol and nitrophenol metabolism by Sphingomonas sp UG30

Sphingomonas sp UG30 is a pentachlorophenol (PCP) degrading bacterial strai n capable of degrading several nitrophenolic compounds, including p-nitroph enol (PNP), a,l-dinitrophenol (2,4-DNP), p-nitrocatechol and 4,6-dinitro-o- cresol (DNOC). The ability to degrade both chlorophenolic and nitrophenolic compounds is probably not restricted to UG30, but may also be possessed by other pentachlorophenol-degrading Sphingomonas spp. The interesting questi on arises as to whether there is any point of convergence between the initi al pathways of PCP and nitrophenol degradation in these microorganisms. The re is some experimental evidence that PCP-4-monooxygenase is involved in me tabolism of both p-nitrophenol and 2,4-dinitrophenol. Further studies are n eeded to confirm this and to examine the role(s) of other PCP-degrading enz ymes in nitrophenol metabolism by this microorganism. In this paper, we rev iew some of the taxonomic, biochemical, physiological and ecological proper ties of Sphingomonas sp UG30 with respect to biodegradation of PCP and nitr ophenolic compounds.