title: Isolation and characterization of a novel simazine-degrading bacterium from agricultural soil of central Chile, Pseudomonas sp. MHP41.
abstract: s-Triazine herbicides are used extensively in South America in agriculture and forestry. In this study, a bacterium designated as strain MHP41, capable of degrading simazine and atrazine, was isolated from agricultural soil in the Quillota valley, central Chile. Strain MHP41 is able to grow in minimal medium, using simazine as the sole nitrogen source. In this medium, the bacterium exhibited a growth rate of mu=0.10 h(-1), yielding a high biomass of 4.2 x 10(8) CFU mL(-1). Resting cells of strain MHP41 degrade more than 80% of simazine within 60 min. The atzA, atzB, atzC, atzD, atzE and atzF genes encoding the enzymes of the simazine upper and lower pathways were detected in strain MHP41. The motile Gram-negative bacterium was identified as a Pseudomonas sp., based on the Biolog microplate system and comparative sequence analyses of the 16S rRNA gene. Amplified ribosomal DNA restriction analysis allowed the differentiation of strain MHP41 from Pseudomonas sp. ADP. The comparative 16S rRNA gene sequence analyses suggested that strain MHP41 is closely related to Pseudomonas nitroreducens and Pseudomonas multiresinovorans. This is the first s-triazine-degrading bacterium isolated in South America. Strain MHP41 is a potential biocatalyst for the remediation of s-triazine-contaminated environments.
authors.affiliation: Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Millennium Nucleus of Microbial Ecology and Environmental Microbiology and Biotechnology EMBA, Departamento de Química, Universidad Técnica Federico Santa María, Valparaíso, Chile.
authors.forename: Marcela
authors.initials: M
authors.lastname: Hernández
authors.forename: Patricio
authors.initials: P
authors.lastname: Villalobos
authors.forename: Verónica
authors.initials: V
authors.lastname: Morgante
authors.forename: Myriam
authors.initials: M
authors.lastname: González
authors.forename: Caroline
authors.initials: C
authors.lastname: Reiff
authors.forename: Edward
authors.initials: E
authors.lastname: Moore
authors.forename: Michael
authors.initials: M
authors.lastname: Seeger
mesh_terms: D001280:Atrazine / Q000378:metabolism; D015373:Bacterial Typing Techniques; D018533:Biomass; D001711:Biotransformation; D002677:Chile; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005798:Genes, Bacterial; D053858:Metabolic Networks and Pathways; D009584:Nitrogen / Q000378:metabolism; D010802:Phylogeny; D011549:Pseudomonas / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D012839:Simazine / Q000378:metabolism*; D012988:Soil Microbiology
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D009584:Nitrogen; D001280:Atrazine; D012839:Simazine