Conflict of interest: The authors have no conflict of interest to declare.
Enhanced degradation of haloacid by heterologous expression in related Burkholderia species
Article first published online: 22 APR 2013
Copyright © 2013 Wiley Periodicals, Inc.
Biotechnology and Bioengineering
Volume 110, Issue 10, pages 2687–2696, October 2013
How to Cite
Su, X., Deng, L., Kong, K. F. and Tsang, J. S. H. (2013), Enhanced degradation of haloacid by heterologous expression in related Burkholderia species. Biotechnol. Bioeng., 110: 2687–2696. doi: 10.1002/bit.24917
- Issue published online: 24 AUG 2013
- Article first published online: 22 APR 2013
- Accepted manuscript online: 8 APR 2013 07:11AM EST
- Manuscript Accepted: 21 MAR 2013
- Manuscript Revised: 8 MAR 2013
- Manuscript Received: 18 DEC 2012
- University Seed Funding Programme for Basic Research. Grant Numbers: 10208275, 10401856
- heterologous expression
Haloacids are environmental pollutant and can be transformed to non-toxic alkanoic acids by microbial dehalogenase. Bacterium Burkholderia species MBA4 was enriched from soil for its ability to bioremediate haloacids such as mono-chloroacetate (MCA), mono-bromoacetate (MBA), 2-mono-chloropropionate, and 2-mono-bromopropionate. MBA4 produces an inducible dehalogenase Deh4a that catalyzes the dehalogenation process. The growth of MBA4 on haloacid also relies on the presence of a haloacid-uptake system. Similar dehalogenase genes can be found in the genome of many related species. However, wildtype Burkholderia caribensis MWAP64, Burkholderia phymatum STM815, and Burkholderia xenovorans LB400 were not able to grow on MCA. When a plasmid containing the regulatory and structural gene of Deh4a was transformed to these species, they were able to grow on haloacid. The specific enzyme activities in these recombinants ranges from 2- to 30-fold that of MBA4 in similar condition. Reverse transcription-quantitative real-time PCR showed that the relative transcript levels in these recombinant strains ranges from 9 to over 1,600 times that of MBA4 in similar condition. A recombinant has produced nearly five times of dehalogenase that MBA4 could ever achieve. While the expressions of Deh4a were more relaxed in these phylogenetically related species, an MCA-uptake activity was found to be inducible. These metabolically engineered strains are better degraders than the haloacid-enriched MBA4. Biotechnol. Bioeng. 2013;110: 2687–2696. © 2013 Wiley Periodicals, Inc.