Recombinant Serratia marcescens nuclease is frequently employed in contemporary downstream processing of viral and protein-based biopharmaceuticals.
The enzyme was first isolated from S. marcescens, a bacilliform Gram-negative bacterium that was discovered in 1819. As an opportunistic human pathogen, it is often responsible for infections in immunocompromised individuals and particularly infections that are acquired in hospitals.
At a molecular level, Serratia nuclease is a DNA/RNA non-specific endonuclease that catalyzes the hydrolysis of double- and single-stranded nucleic acids at the 3′ position of the phosphodiester bonds that connect nucleotides. It cuts DNA and RNA into fragments that are two to five nucleotides long.
Recombinantly produced S. marcescens nuclease was patented by Benzon Pharma and originally marketed under the name Benzonase. These days, S. marcescens nuclease is manufactured by other suppliers, including by c-Lecta under the name Denarase.
In bioprocessing, this nuclease is used to digest host cell DNA and RNA that is commonly found in harvested bioreactor fluid and cell lysates. Digesting these nucleic acids aids in downstream processing by lowering feed-stream viscosity and often improving the efficiency of host-cell DNA clearance by chromatographic and filtration methods.
In addition to its role as a pathogen, wild-type S. marcescens is abundantly present in the environment. For example, it is responsible for the orange-pink film that sometimes forms on damp shower curtains. Although often assumed to be mold, this pink slime is actually an S. marcescens biofilm that feeds on soap residue.