DSpace
 

DSpace at IIT Bombay >
IITB Publications >
Article >

Please use this identifier to cite or link to this item: http://dspace.library.iitb.ac.in/jspui/handle/10054/12052

Title: Biodegradation of phthalate isomers by Pseudomonas aeruginosa PP4, Pseudomonas sp PPD and Acinetobacter lwoffii ISP4
Authors: VAMSEE-KRISHNA, C
MOHAN, Y
PHALE, PS
Keywords: terephthalate degradation
dioxygenase reductase
purification
metabolism
pathway
dimethylphthalate
testosteroni
oxygenase
esterase
form
Issue Date: 2006
Publisher: SPRINGER
Citation: APPLIED MICROBIOLOGY AND BIOTECHNOLOGY, 72(6), 1263-1269
Abstract: Pseudomonas aeruginosa PP4, Pseudomonas sp. PPD and Acinetobacter lwoffii ISP4 capable of utilizing phthalate isomers were isolated from the soil using enrichment culture technique. The strain ISP4 metabolizes isophthalate, while PPD and PP4 utilizes all three phthalate isomers (ortho-, iso- and tere-) as the sole carbon source. ISP4 utilizes isophthalate (0.1%) more rapidly (doubling time, 0.9 h) compared to PPD (4.64 h), PP4 (7.91 h) and other reported strains so far. The metabolic pathways in these isolates were initiated by dihydroxylation of phthalate isomers. Phthalate is hydroxylated to 3,4-dihydro-3,4-dihydroxyphthalate and 4,5-dihydro-4,5-dihydroxyphthalate in strains PP4 and PPD, respectively; while terephthalate is hydroxylated to 2-hydro-1,2-dihydroxyterephthalate. All three strains hydroxylate isophthalate to 4-hydro-3,4-dihydroxyisophthalate. The generated dihydroxyphthalates were subsequently metabolized to 3,4-dihydroxybenzoate (3,4-DHB) which was further metabolized by ortho ring-cleavage pathway. PP4 and PPD cells grown on phthalate, isophthalate or terephthalate showed respiration on respective phthalate isomer and the activity of corresponding ring-hydroxylating dioxygenase, suggesting the carbon source specific induction of three different ring-hydroxylating dioxygenases. We report, for the first time, the activity of isophthalate dioxygenase and its reductase component in the cell-free extracts. The enzyme showed maximum activity with reduced nicotinamide adenine dinucleotide (NADH) in the pH range 8-8.5. Cells grown on glucose failed to respire on phthalate isomers and 3,4-DHB and showed significantly low activities of the enzymes suggesting that the enzymes are inducible.
URI: http://dx.doi.org/10.1007/s00253-006-0413-7
http://dspace.library.iitb.ac.in/xmlui/handle/10054/12052
http://hdl.handle.net/10054/12052
ISSN: 0175-7598
Appears in Collections:Article

Files in This Item:

There are no files associated with this item.

View Statistics

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

Valid XHTML 1.0! DSpace Software Copyright © 2002-2010  Duraspace - Feedback