text: Bacteria are often viewed as the main consumers of DOC, but they can also produce DOC during cell division and viral lysis. The biochemical components of bacteria are largely the same as other organisms, but some compounds from the cell wall are unique and are used to trace bacterial derived DOC (e.g., peptidoglycan). These compounds are widely distributed in the ocean, suggesting that bacterial DOC production could be important in marine systems. Viruses are the most abundant life forms in the oceans infecting all life forms including algae, bacteria and zooplankton. After infection, the virus either enters a dormant (lysogenic) or productive (lytic) state. The lytic cycle causes disruption of the cell(s) and release of DOC.