Fig. 5.

Transcription studies on the two putative cholesterol oxidase ChoOx-1 (A) and ChoOx-2 (B) genes of G. cholesterolivorans. Specific RT-PCR products amplified from RNA isolated from cells grown in minimal medium with citrate (Ci; control), octanoic acid (C₈), and cholesterol (C₂₇). H₂O is the control without cDNA. The RT⁻ assays are controls to exclude any contamination with DNA and chrD is the assay with chromosomal DNA to verify the functionality of the PCR primers (see Table S3 in the supplemental material).