Characterization of a ring-hydroxylating dioxygenase from phenanthrene-degrading Sphingomonas sp. strain LH128 able to oxidize benz[a]anthracene.

Luc Schuler (1) , Yves Jouanneau (2) , Sinéad M Ní Chadhain (3) , Christine Meyer (2) , Maria Pouli (1) , Gerben J Zylstra (3) , Pascal Hols (1) , Spiros N Agathos (1)

1 UCL - UCL - Unité de Génie Biologique
2 LCBM - UMR 5249 - Laboratoire de Chimie et Biologie des Métaux
3 Biotechnology center - Rutgers University,

Sphingomonas sp. strain LH128 was isolated from a polycyclic aromatic hydrocarbon (PAH)-contaminated soil using phenanthrene as the sole source of carbon and energy. A dioxygenase complex, phnA1fA2f, encoding the alpha and beta subunit of a terminal dioxygenase responsible for the initial attack on PAHs, was identified and isolated from this strain. PhnA1f showed 98%, 78%, and 78% identity to the alpha subunit of PAH dioxygenase from Novosphingobium aromaticivorans strain F199, Sphingomonas sp. strain CHY-1, and Sphingobium yanoikuyae strain B1, respectively. When overexpressed in Escherichia coli, PhnA1fA2f was able to oxidize low-molecular-weight PAHs, chlorinated biphenyls, dibenzo-p-dioxin, and the high-molecular-weight PAHs benz[a]anthracene, chrysene, and pyrene. The action of PhnA1fA2f on benz[a]anthracene produced two benz[a]anthracene dihydrodiols.

Domaines: Biochimie [q-bio.BM]

Luc Schuler, Yves Jouanneau, Sinéad M Ní Chadhain, Christine Meyer, Maria Pouli, et al.. Characterization of a ring-hydroxylating dioxygenase from phenanthrene-degrading Sphingomonas sp. strain LH128 able to oxidize benz[a]anthracene.. Applied Microbiology and Biotechnology, 2009, 83 (3), pp.465-75. ⟨10.1007/s00253-009-1858-2⟩. ⟨hal-01063081⟩