Bd-Cytochrome (IMAGE) Lomonosov Moscow State University Caption Schematic structure of the bd-cytochrome. The bd-cytochrome is located in the bacterial inner (cytoplasmic) membrane. Next -- an <i>Escherichia coli</i> bacterium (a bacterium encounters a molecule of hydrogen sulfide (H2S). Credit Vitaly Borisov Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.