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Metabolic engineering of Pseudomonas putida for the simultaneous biodegradation of benzene, toluene, and p-xylene mixture

Journal Article · · Biotechnology and Bioengineering; (United States)
; ;  [1]
  1. Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Biotechnology

For the complete biodegradation of a mixture of benzene, toluene, and p-xylene (BTX), a critical metabolic step that can connect two existing metabolic pathways of aromatic compounds (the tod and the tol pathways) was determined. Toluate-cis-glycol dehydrogenase in the tol pathway was found to attack benzene-cis-glycol, toluene-cis-glycol, and p-xylene-cis-glycol, which are metabolic intermediates of the tod pathway. Based on this observation, a hybrid strain, Pseudomonas putida TB101, was constructed by introduction of the TOL plasmid pWW0 into P. putida F39/D, a derivative of P. putida F1, which is unable to transform cis-glycol compounds to corresponding catechols. The metabolic flux of BTX into the tod pathway was redirected to the tol pathway at the level of cis-glycol compounds by the action of toluate-cis-glycol dehydrogenase in P. putida TB101, resulting in the simultaneous mineralization of BTX mixture without accumulation of any metabolic intermediates. The profile of specific degradation rates showed a similar pattern as that of the specific growth rate of the microorganism, and the maximum specific degradation rates of benzene, toluene, and p-xylene were determined to be about 0.27, 0.86, and 2.89 mg/mg biomass/h, respectively. P. putida TB101 is the first reported microorganisms that mineralizes BTX mixture simultaneously.

OSTI ID:
7264937
Journal Information:
Biotechnology and Bioengineering; (United States), Journal Name: Biotechnology and Bioengineering; (United States) Vol. 43:11; ISSN BIBIAU; ISSN 0006-3592
Country of Publication:
United States
Language:
English