Characterization of a para-nitrophenol catabolic cluster in Pseudomonas sp. strain NyZ402 and construction of an engineered strain capable of simultaneously mineralizing both para- and ortho-nitrophenols.
Pseudomonas sp. strain NyZ402 was isolated for its ability to grow on para-nitrophenol (PNP) as a sole source of carbon, nitrogen, and energy, and was shown to degrade PNP via an oxidization pathway. This strain was also capable of growing on hydroquinone or catechol. A 15, 818 bp DNA fragment extending from a 800-bp DNA fragment of hydroxyquinol 1,2-dioxygenase gene (pnpG) was obtained by genome walking. Sequence analysis indicated that the PNP catabolic gene cluster (pnpABCDEFG) in this fragment shared significant similarities with a recently reported gene cluster responsible for PNP degradation from Pseudomonas sp. strain WBC-3. PnpA is PNP 4-monooxygenase converting PNP to hydroquinone via benzoquinone in the presence of NADPH, and genetic analysis indicated that pnpA plays a key role in PNP degradation. pnpA1 present in the upstream of the cluster (absent in the cluster from strain WBC-3) encodes a protein sharing as high as 55% identity with PnpA, but was not involved in PNP degradation by either in vitro or in vivo analyses. Furthermore, an engineered strain capable of growing on PNP and ortho-nitrophenol (ONP) was constructed by introducing onpAB (encoding ONP monooxygenase and ortho-benzoquinone reductase which catalyzed the transformation of ONP to catechol) from Alcaligenes sp. strain NyZ215 into strain NyZ402.
Wei
Qing
Q
Center for Applied and Environmental Microbiology (cAEM) and State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, 430071, Wuhan, China.
Liu
Hong
H
Zhang
Jun-Jie
JJ
Wang
Song-He
SH
Xiao
Yi
Y
Zhou
Ning-Yi
NY
D000421:Alcaligenes / Q000201:enzymology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D005818:Genetic Engineering; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009596:Nitrophenols / Q000737:chemistry / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D011549:Pseudomonas / Q000235:genetics* / Q000378:metabolism*
D001426:Bacterial Proteins; D009596:Nitrophenols; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases