Archives of Microbiology

, Volume 191, Issue 6, pp 485–492

Genetic and biochemical analyses of chlorobenzene degradation gene clusters in Pandoraea sp. strain MCB032

  • Xi-Wen Jiang
  • Hong Liu
  • Ying Xu
  • Shu-Jun Wang
  • David J. Leak
  • Ning-Yi Zhou
Original Paper

DOI: 10.1007/s00203-009-0476-9

Cite this article as:
Jiang, X., Liu, H., Xu, Y. et al. Arch Microbiol (2009) 191: 485. doi:10.1007/s00203-009-0476-9

Abstract

Pandoraea sp. strain MCB032 was isolated as an emerging chlorobenzene degrader from a functionally stable bioreactor where species succession had occurred. In this study, two gene clusters encoding chlorobenzene metabolic functions have been cloned. Within the cbs gene cluster, CbsA and CbsB are similar to the chlorobenzene dioxygenase and the cis-chlorobenzene dihydrodiol dehydrogenase in Ralstonia sp. JS705 and shown to transform chlorobenzene to 3-chlorocatechol. The clc gene cluster shows strong similarity to the clc genes of Ralstonia sp. JS705 and encodes chlorocatechol 1,2-dioxygenase (ClcA) and other enzymes, which catalyze the conversion of chlorocatechol to 3-oxoadipate. The Michaelis constants (Km) values of ClcA for catechol, 3-methylcatechol and 3-chlorocatechol were determined as 10.0, 8.9 and 3.4 μM, respectively. CbsX, a putative transport protein present in the cbs cluster of strain MCB032 but not in those of other chlorobenzene degraders, shows 76 and 53% identities to two previously identified transport proteins involved in toluene degradation, TbuX from Ralstonia pickettii PKO1 and TodX from Pseudomonas putida F1. The presence of the transport protein in strain MCB032 likely provides a mechanistic explanation for its higher chlorobenzene affinity and may well be the basis for the competitive advantage of this strain in the bioreactor.

Keywords

ChlorobenzeneChlorocatecholDegradationPandoraea

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Xi-Wen Jiang
    • 1
  • Hong Liu
    • 1
  • Ying Xu
    • 1
  • Shu-Jun Wang
    • 1
  • David J. Leak
    • 2
  • Ning-Yi Zhou
    • 1
  1. 1.State Key Laboratory of Virology, Wuhan Institute of VirologyChinese Academy of SciencesWuhanChina
  2. 2.Division of Biology, Faculty of Natural SciencesImperial College LondonLondonUK