Table 1.

Bacterial strains and plasmids used in this study

Plasmid or strain	Relevant characteristicsa	Source or reference
Plasmids
pCDFDuet-1	Expression vector; CDF (pCloDF13 replicon), encodes two multiple cloning sites, each of which is preceded by a T7 promoter, a lac operator, and a ribosome binding site; SmR	Merck Millipore, Germany
pCDF-dhaAwt	pCDFDuet-1 carrying wild-type dhaA gene (encoding haloalkane dehalogenase) from Rhodococcus rhodochrous NCIMB 13064	[22]
pCDF-dhaA31	pCDFDuet-1 carrying mutant variant (dhaA31) of haloalkane dehalogenase gene	[22]
pETDuet-1	Expression vector; ColE1 (pBR322 replicon), encodes two multiple cloning sites, each of which is preceded by a T7 promoter, a lac operator, and a ribosome binding site; AmpR	Merck Millipore, Germany
pETDuet-echA-hheC	pETDuet-1 carrying wild-type echA and hheC genes (encoding epoxide hydrolase and haloalcohol dehalogenase) from Agrobacterium radiobacter AD1	[22]
pACYCDuet-1	Expression vector; P15A (pACYC184 replicon), encodes two multiple cloning sites, each of which is preceded by a T7 promoter, a lac operator, and a ribosome binding site; CmR	Merck Millipore, Germany
pACYC-echA-hheC	pACYC-1 carrying the wild-type echA and hheC genes (encoding epoxide hydrolase and haloalcohol dehalogenase) from Agrobacterium radiobacter AD1	[22]
Escherichia coli
DH5α	Cloning host; Φ80lacZΔM15 recA1 endA1 gyrA96 thi-1 hsdR17(r−Km+K) supE44 relA1 deoR Δ(lacZYA-argF)U169	Life Technologies, USA
BL21(DE3)	Expression host; F− ompT gal dcm lon hsdS B(r−B m−B) λ(DE3 [lacI Q lacUV5-T7 gene 1 ind1 sam7 nin5])	Life Technologies, USA
Host control	E. coli BL21(DE3) transformed with pCDF and pETDuet, control strain with empty plasmids	This study
degWT	E. coli BL21(DE3) transformed with pCDF-dhaAwt and pETDuet-echA-hheC	[22]
deg31	E. coli BL21(DE3) transformed with pCDF-dhaA31 and pETDuet-echA-hheC	[22]
deg31opt	E. coli BL21(DE3) transformed with pCDF-dhaA31 and pACYC-echA-hheC	[22]

^aAntibiotic markers: Sm streptomycin, Amp ampicillin, Cm chloramphenicol