ISOLATION AND PROPERTIES OF AN EXOCELLULAR NUCLEASE OF SERRATIA MARCESCENS

Abstract
The exocellular nuclease of Serratia marcescens (isolated by anion-exchange chromato-graphy on diethylaminoethyl-Sephadex) depolymerized deoxyribo-nucleic-acid, ribonucleic-acid and the polynucleotide which is refractory to pancreatic ribonuclease activity. The enzyme was tentatively classified as a nonspecific phosphodiesterase. Magnesium was essential for activity which was optimal at pH 8.8. The purified enzyme was completely inactivated by heating at 50 C for 15 min.