The nucleotide and amino acid sequences were compared with the EMBL, SwissProt and GenBank databases. blast searches were carried out at the NCBI (http://www.ncbi.nlm.nih.gov/BLAST/). DNA sequences were analysed using the sci-ed software package. Sequence alignments were performed with the clustalw2 program of the EBI (http://www.ebi.ac.uk/Tools/clustalw2/),
and visualized with the jalview 2.6.1 software (Waterhouse et al., 2009). Total RNA was extracted from late-exponential phase E1 cells cultivated on acetate, n-dodecane, n-hexadecane, Trichostatin A n-octadecane and n-eicosane using the TRIzol reagent (Amersham Pharmacia) and method. To prepare DNA-free RNA, 15 μg of total RNAs was treated with 5 U of RNase-free DNase I (Fermentas) according to the supplier’s protocol. The quantity and the quality of the recovered RNAs were verified by means of spectrophotometry (Nanodrop 1000) and agarose gel electrophoresis. First-strand cDNA synthesis of 2 μg of total RNA in a final volume of 20 μL was carried out with RevertAid M-MuLV Reverse Transcriptase (Fermentas), using random hexamers. For real-time PCR, 1 μL of cDNA was mixed
with Power SYBR Green PCR Master Mix (Applied Biosystems), 5 pmol of forward primer and 5 pmol of reverse primer in a final volume of 20 μL in three replicates. No-template controls were included. The primers for the 16S rRNA gene and for buy RO4929097 nine selected ORFs were designed using the primer express software (Applied Biosystems). Real-time PCR was carried out with the ABI Prism 7000 Sequence Detection System (Applied Biosystems) with the following protocol: 45 cycles at 95 °C for 15 s, followed by 60 °C for 1 min. The
specificity of the amplifications was verified at the end of the PCR run through use of the abi prism dissociation curve analysis software. The expression levels of investigated genes were normalized to 16S rRNA gene levels and were correlated to the amounts of the corresponding transcripts in samples grown on acetate. The normalized relative transcript levels were obtained by the method (Livak & Schmittgen, 2001). The expression Aspartate vectors for complementation studies were constructed applying the PCR products amplified by alkBPromF and rubCFLAG primers from Dietzia spp. The PCR fragments were EcoRI digested and ligated between the HindII/EcoRI sites of the streptomycin cassette-carrying pNV18Sm shuttle vector (Szvetnik et al., 2010). The plasmid pNV18Sm-E1BRF obtained was introduced into either wild-type or ΔBR cells, while pNV18Sm expressing AlkB-Rubs of four other Dietzia spp. was introduced into ΔBR cells (Table 1). Control transformations with pNV18Sm vectors were also included. The growth kinetics of each cell line on n-eicosane was determined as described above.