ISOLATION AND PROPERTIES OF AN EXOCELLULAR NUCLEASE OF SERRATIA MARCESCENS.

Area of Science:

• Microbiology
• Enzymology
• Molecular Biology

Background:

• Serratia marcescens is a bacterium known to produce extracellular enzymes.
• Understanding microbial nucleases is crucial for molecular biology applications.

Purpose of the Study:

• To isolate and characterize an exocellular nuclease from Serratia marcescens.
• To determine the enzymatic properties and substrate specificity of the isolated nuclease.

Main Methods:

• Isolation of the exocellular nuclease using anion-exchange chromatography (diethylaminoethyl-Sephadex).
• Assay of enzyme activity on deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
• Determination of optimal pH, magnesium dependency, and thermal stability.

Main Results:

• The exocellular nuclease depolymerized both DNA and RNA.
• The enzyme also degraded a polynucleotide resistant to pancreatic ribonuclease.
• Activity was optimal at pH 8.8, required magnesium, and was lost upon heating to 50°C for 15 minutes.
• The enzyme was classified as a nonspecific phosphodiesterase.

Conclusions:

• Serratia marcescens produces a versatile exocellular nuclease with broad substrate specificity.
• The enzyme's properties suggest its potential utility in various biochemical applications.
• Further research could elucidate its precise mechanism and potential therapeutic or industrial uses.