title: Extracellular deoxyribonuclease production by a thermophile, Streptomyces thermonitrificans.
abstract: A thermophilic bacterial strain, Streptomyces thermonitrificans, produced high levels of extracellular deoxyribonuclease (DNase) when grown on NBG medium (containing 1% peptone, 0.3% beef extract, 1% glucose and 0.5% NaCl). Maximum DNase activity (140 U x ml(-1)) was obtained, in 24 h, when the culture was grown on modified NBG medium (containing 1.3% beef extract, 1% glucose, 0.5% NaCl and 50 microM Mn2+ at 45 degrees C. The crude enzyme showed higher activity on native DNA than on sonicated and heat denatured DNA. Moreover, addition of Mn2+ in the assay mixture resulted in a significant stimulation (10-15 fold) of the enzyme activity.
authors.affiliation: Division of Biochemical Sciences, National Chemical Laboratory, Pune 411 008, India.
authors.forename: S S
authors.initials: SS
authors.lastname: Deshmukh
authors.forename: V
authors.initials: V
authors.lastname: Shankar
mesh_terms: D003851:Deoxyribonucleases / Q000096:biosynthesis* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008345:Manganese / Q000494:pharmacology; D008670:Metals / Q000494:pharmacology; D013302:Streptomyces / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D013696:Temperature
chemical_list: D008670:Metals; D008345:Manganese; D003851:Deoxyribonucleases