Each growth condition was repeated once. Total RNA was extracted according to the protocol provided by Qiagen (RNeasy Mini Kit). For cell harvest, 2 volumes of RNAprotect Bacteria Reagent (Qiagen) were added to 1 volume bacterial culture and mixed vigorously. The solution was incubated at room temperature for 5 min and immediately centrifuged at 5000 g for 10 min. For cell lysis, the cell pellet was resuspended in a 10% aliquot of the initial
Lapatinib sample volume containing 1 mg mL−1 lysozyme in 10 mM Tris/HCl, 1 mM EDTA, pH 8.0, and incubated at room temperature for 20 min. Then, 1.8 mL RLT buffer (Qiagen) containing 1% (v/v) β-mercaptoethanol was added and mixed intensively, Selumetinib order followed by the addition of 1.2 mL ethanol.
The RNA solution was purified using the RNeasy Mini Kit, by applying the total volume stepwise to one column. On-column DNase digestion was performed twice for 20 min to ensure the complete removal of genomic DNA. RNA integrity and purity were checked by agarose gel electrophoresis. cDNA synthesis was performed from about 10 μg total RNA with a statistically distributed mixture of hexanucleotides as primers (random priming) using SuperscriptII (Invitrogen) reverse transcriptase according to the manufacturer’s protocols. An aliquot of 25 μg cDNA was sequenced using the Genome Analyzer II at GATC Biotech AG (Konstanz). For this, the cDNA was nebulized to generate fragments <800 bp long. A terminal ‘A’ was then transferred to the 3′ end and cDNA fragments were ligated to adapters, purified and bridge amplified. Thirty-six cycles of sequencing-by-synthesis were performed crotamiton for each library using the Genome Analyzer GAII SR. illumina genome analyzer pipeline
software (version 0.2) was used to qualify reads (Klockgether et al., 2010). Sequence reads that passed the default signal quality filter and were not aligned by ELAND (Efficient Large-Scale Alignment of Nucleotide Databases) to a reference of the P. putida rRNA genes were used for gene expression analysis. The reads were subsequently aligned to the P. putida genome (NC_002947.3) using the bowtie software package (Langmead et al., 2009). The remaining reads mapped to rRNA were subsequently excluded with a custom PERL script. Four nucleotides were trimmed from the 3′ end of each read and a seed size of 28 bp was used, in which two mismatches were allowed. The quality mismatch sum was 100 and results were transformed into a SAM format (command line: bowtie -t putida -l 28 -e 100 –best –sam -3 4 -n 2 -p 7). A summary table was then generated using the integrative web analysis tool galaxy (Giardine et al., 2005). The functions ‘coverage’ and ‘join’ were used, respectively, to summarize (1) the coverage of each ORF from the P. putida NCBI annotation (version NC_002947.