title: Fermentation studies of the secretion of Serratia marcescens nuclease by Escherichia coli.
abstract: The secretion of a Serratia marcescens nuclease was followed by fermentation with Escherichia coli. A plasmid, p403-SD2, carrying a 1.3-kilobase-pair insert with a 0.4-kilobase-pair region upstream of the nuclease gene caused a growth-phase-regulated expression of nuclease in E. coli in the same way as that seen in S. marcescens. Deletion of the regulatory gene generating plasmid p403-Rsa1 resulted in a constitutive expression of the nuclease. Anaerobiosis stimulated the expression from p403-SD2 in stationary growth phase by a factor of 10 compared with expression stimulated by cultivation in aerobic conditions; no such effect was found for plasmid p403-Rsa1. Different nutritional factors caused the expression level and the amount of extracellular nuclease to vary more when nuclease was expressed from plasmid p403-SD2 than when it was expressed from plasmid p403-Rsa1. A correlation between the regulatory gene and the extracellular secretion of nuclease is proposed.
authors.affiliation: Department of Biotechnology, Technical University of Denmark, Lyngby.
authors.forename: K
authors.initials: K
authors.lastname: Biedermann
authors.forename: H
authors.initials: H
authors.lastname: Fiedler
authors.forename: B S
authors.initials: BS
authors.lastname: Larsen
authors.forename: E
authors.initials: E
authors.lastname: Riise
authors.forename: C
authors.initials: C
authors.lastname: Emborg
authors.forename: P K
authors.initials: PK
authors.lastname: Jepsen
mesh_terms: D001431:Bacteriological Techniques; D004706:Endodeoxyribonucleases; D004720:Endonucleases / Q000235:genetics / Q000378:metabolism*; D004722:Endoribonucleases; D004926:Escherichia coli / Q000235:genetics; D005285:Fermentation; D005809:Genes, Regulator; D007700:Kinetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism*; D012706:Serratia marcescens / Q000201:enzymology* / Q000254:growth & development
chemical_list: D011994:Recombinant Proteins; D004706:Endodeoxyribonucleases; D004720:Endonucleases; D004722:Endoribonucleases; C021835:Serratia marcescens nuclease