title: Isolation of a strain of Agrobacterium tumefaciens (Rhizobium radiobacter) utilizing methylene urea (ureaformaldehyde) as nitrogen source.
abstract: Methylene ureas (MU) are slow-release nitrogen fertilizers degraded in soil by microbial enzymatic activity. Improved utilization of MU in agricultural production requires more knowledge about the organisms and enzymes responsible for its degradation. A Gram-negative, MU-degrading organism was isolated from a soil in Sacramento Valley, California. The bacterium was identified as Agrobacterium tumefaciens (recently also known as Rhizobium radiobacter) using both genotypic and phenotypic characterization. The pathogenic nature of the organism was confirmed by a bioassay on carrot disks. The MU-hydrolyzing enzyme (MUase) was intracellular and was induced by using MU as a sole source of nitrogen. The bacterial growth was optimized in NH4Cl, urea, or peptone, whereas the production and specific activity of MUase were maximized with either NH4Cl or urea as a nitrogen source. The result has a practical significance, demonstrating a potential to select for this plant pathogen in soils fertilized with MU.
authors.affiliation: Department of Land, Air, and Water Resources, University of California, Davis 95616, USA. mekoivunen@ucdavis.edu
authors.forename: Marja E
authors.initials: ME
authors.lastname: Koivunen
authors.forename: Christophe
authors.initials: C
authors.lastname: Morisseau
authors.forename: William R
authors.initials: WR
authors.lastname: Horwath
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Hammock
mesh_terms: D016960:Agrobacterium tumefaciens / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism* / Q000472:pathogenicity; D015373:Bacterial Typing Techniques; D018533:Biomass; D002140:California; D004269:DNA, Bacterial / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000737:chemistry / Q000302:isolation & purification; D018552:Daucus carota / Q000382:microbiology; D005557:Formaldehyde / Q000378:metabolism*; D020459:Genes, rRNA; D005838:Genotype; D006867:Hydrolases / Q000032:analysis; D008969:Molecular Sequence Data; D009566:Nitrates / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D017680:Potassium Compounds / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D014508:Urea / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D009566:Nitrates; D017680:Potassium Compounds; D000644:Quaternary Ammonium Compounds; D012336:RNA, Ribosomal, 16S; D005557:Formaldehyde; C028278:urea formaldehyde foam; D014508:Urea; D006867:Hydrolases; C023844:potassium nitrate