title: Degradation of pentaerythritol tetranitrate by Enterobacter cloacae PB2.
abstract: A mixed microbial culture capable of metabolizing the explosive pentaerythritol tetranitrate (PETN) was obtained from soil enrichments under aerobic and nitrogen-limiting conditions. A strain of Enterobacter cloacae, designated PB2, was isolated from this culture and was found to use PETN as a sole source of nitrogen for growth. Growth yields suggested that 2 to 3 mol of nitrogen was utilized per mol of PETN. The metabolites pentaerythritol dinitrate, 3-hydroxy-2,2-bis-[(nitrooxy)methyl]propanal, and 2,2-bis-[(nitrooxy)methyl]-propanedial were identified by mass spectrometry and 1H-nuclear magnetic resonance. An NADPH-dependent PETN reductase was isolated from cell extracts and shown to liberate nitrite from PETN, producing pentaerythritol tri- and dinitrates which were identified by mass spectrometry. PETN reductase was purified to apparent homogeneity by ion-exchange and affinity chromatography. The purified enzyme was found to be a monomeric flavoprotein with a M(r) of approximately 40,000, binding flavin mononucleotide noncovalently.
authors.affiliation: Institute of Biotechnology, University of Cambridge, United Kingdom.
authors.forename: P R
authors.initials: PR
authors.lastname: Binks
authors.forename: C E
authors.initials: CE
authors.lastname: French
authors.forename: S
authors.initials: S
authors.lastname: Nicklin
authors.forename: N C
authors.initials: NC
authors.lastname: Bruce
mesh_terms: D000332:Aerobiosis; D001673:Biodegradation, Environmental; D016972:Enterobacter cloacae / Q000302:isolation & purification / Q000378:metabolism*; D004785:Environmental Pollutants / Q000378:metabolism; D007700:Kinetics; D010088:Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism; D010417:Pentaerythritol Tetranitrate / Q000378:metabolism*; D012988:Soil Microbiology; D013379:Substrate Specificity
chemical_list: D004785:Environmental Pollutants; D010417:Pentaerythritol Tetranitrate; D010088:Oxidoreductases; C098939:pentaerythritol tetranitrate reductase