title: Enzyme activity and gene expression profiles of Xanthobacter autotrophicus GJ10 during aerobic biodegradation of 1,2-dichloroethane.
abstract: Xanthobacter autotrophicus GJ10 has been widely studied because of its ability to degrade halogenated compounds, especially 1,2-dichloroethane (1,2-DCA), which is achieved through chromosomal as well as plasmid pAUX1 encoded 1,2-DCA degrading genes. This work described the gene expression and enzyme activity profiles as well as the intermediates formed during the 1,2-DCA degradation by this organism. A correlation between gene expression, enzyme activity and metabolic intermediates, after the induction of GJ10 grown culture with 1,2-DCA, was established at different time intervals. Haloalkane dehalogenase (dhlA) and haloacid dehalogenase (dhlB) were constitutively expressed while the expression of alcohol dehydrogenase (max) and aldehyde dehydrogenase (ald) was found to be inducible. The DhlA and DhlB activities were relatively higher compared to that of the inducible enzymes, Max and Ald. To the best of our knowledge, this is the first study to correlate gene expression profiles with enzyme activity and metabolite formation during 1,2-DCA degradation process in GJ10. Findings from this study may assist in fully understanding the mechanism of 1,2-DCA degradation by GJ10. It could also assist in the design and implementation of appropriate bioaugmentation strategies for complete removal of 1,2-DCA from contaminated environment.
authors.affiliation: Discipline of Microbiology, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal (Westville Campus), Private Bag X54001, Durban, 4000, Republic of South Africa.
authors.forename: Ajit
authors.initials: A
authors.lastname: Kumar
authors.forename: Balakrishna
authors.initials: B
authors.lastname: Pillay
authors.forename: Ademola O
authors.initials: AO
authors.lastname: Olaniran
mesh_terms: D000332:Aerobiosis; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D003001:Cloning, Molecular; D005025:Ethylene Dichlorides / Q000378:metabolism*; D006867:Hydrolases / Q000235:genetics / Q000378:metabolism*; D020584:Xanthobacter / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D005025:Ethylene Dichlorides; C024565:ethylene dichloride; D006867:Hydrolases; C034507:2-haloacid dehalogenase; C046137:haloalkane dehalogenase