Degradation of phenanthrene via meta-cleavage of 2-hydroxy-1-naphthoic acid by Ochrobactrum sp. strain PWTJD.
The present study describes the assimilation of phenanthrene by an aerobic bacterium, Ochrobactrum sp. strain PWTJD, isolated from municipal waste-contaminated soil sample utilizing phenanthrene as a sole source of carbon and energy. The isolate was identified as Ochrobactrum sp. based on the morphological, nutritional and biochemical characteristics as well as 16S rRNA gene sequence analysis. A combination of chromatographic analyses, oxygen uptake assay and enzymatic studies confirmed the degradation of phenanthrene by the strain PWTJD via 2-hydroxy-1-naphthoic acid, salicylic acid and catechol. The strain PWTJD could also utilize 2-hydroxy-1-naphthoic acid and salicylic acid, while the former was metabolized by a ferric-dependent meta-cleavage dioxygenase. In the lower pathway, salicylic acid was metabolized to catechol and was further degraded by catechol 2,3-dioxygenase to 2-hydroxymuconoaldehyde acid, ultimately leading to tricarboxylic acid cycle intermediates. This is the first report of the complete degradation of a polycyclic aromatic hydrocarbon molecule by Gram-negative Ochrobactrum sp. describing the involvement of the meta-cleavage pathway of 2-hydroxy-1-naphthoic acid in phenanthrene assimilation.
Department of Microbiology, Bose Institute, Kolkata, India.
Debajyoti
D
Ghosal
Joydeep
J
Chakraborty
Pratick
P
Khara
Tapan K
TK
Dutta
D015373:Bacterial Typing Techniques; D001711:Biotransformation; D002264:Carboxylic Acids / Q000378:metabolism; D002396:Catechols / Q000378:metabolism; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D009281:Naphthalenes / Q000378:metabolism; D042041:Ochrobactrum / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010616:Phenanthrenes / Q000378:metabolism*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D020156:Salicylic Acid / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology
D002264:Carboxylic Acids; D002396:Catechols; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D009281:Naphthalenes; D010616:Phenanthrenes; D012336:RNA, Ribosomal, 16S; C085312:1-naphthoic acid; C031181:phenanthrene; C034221:catechol; D020156:Salicylic Acid