Transcriptome profiles of a riboflavin-producing B.subtilis RH33 and wild type B.subtilis 168

The transcriptome profiles of a riboflavin-producing recombinant Bacillus subtilis RH33 and wild type Bacillus subtilis 168 were compared using DNA microarrays to identify the target genes for further enhancing riboflavin production. Transcriptome profiles of a riboflavin-producing B. subtilis RH33 were compared with those of the wild-type B. subtilis 168 as a control strain during exponentially growing period on LBG medium. These conditions corresponded to the state of high riboflavin production, which was growth related. For each comparison, two independent cultivations on LB medium with 1% glucose were performed, and exponentially growing cells (OD600 3–6) were harvested. The synthesis of cDNA and biotin-labeled cRNA were carried out exactly as described in the Affymetrix GeneChip Expression Analysis Technical Manual (2000).