Serratia species are unique in the Enterobacteriaceae by producing which extracellular hydrolytic enzyme?

Serratia species are unique in the Enterobacteriaceae by producing which extracellular hydrolytic enzyme?

• A. DNase
• B. Hyaluronidase
• C. Kinase
• D. NADase

Answer: (A)

Serratia is distinguished among Enterobacteriaceae by secreting an extracellular DNase, an enzyme that hydrolyzes DNA outside the cell. In the lab, this is shown with a DNase test: colonies that produce DNase create a clear zone (or color change) around them as they break down the surrounding DNA in the medium. This DNase activity is what uniquely identifies Serratia in this family, unlike the other enzymes listed, which are associated with different organisms and are not characteristic markers for Serratia in Enterobacteriaceae.

Serratia is distinguished among Enterobacteriaceae by secreting an extracellular DNase, an enzyme that hydrolyzes DNA outside the cell. In the lab, this is shown with a DNase test: colonies that produce DNase create a clear zone (or color change) around them as they break down the surrounding DNA in the medium. This DNase activity is what uniquely identifies Serratia in this family, unlike the other enzymes listed, which are associated with different organisms and are not characteristic markers for Serratia in Enterobacteriaceae.