title: The diversity and abundance of phytase genes (β-propeller phytases) in bacterial communities of the maize rhizosphere.
abstract: The ecology of microbial communities associated with organic phosphorus (P) mineralization in soils is still understudied. Here, we assessed the abundance and diversity of bacteria harbouring genes encoding β-propeller phytases (BPP) in the rhizosphere of traditional and transgenic maize cultivated in two Brazilian soils. We found a soil-dependent effect towards a higher abundance of phytase genes in the rhizosphere, and an absence of any impact of plant genotype. Phylogenetic analyses indicated members of the genera Pseudomonas, Caulobacter, Idiomarina and Maricaulis, close to 'uncultured bacteria', to constitute the dominant bacteria hosting this gene. The results obtained validate a methodology to target bacteria that are involved in the organic P cycle, and depict the responsiveness of such bacteria to the rhizosphere, albeit in dependency of the soil in which maize is cultivated. The data also identified the major bacterial groups that are associated with the organic P mineralization function.
  
  
  CONCLUSIONS
  Micro-organisms play a key role in nutrient balance in soil ecosystems that are essential to life on the planet. However, some processes such as organic phosphorus mineralization, an important source of phosphorus supply in soil, is poorly studied mainly due the absence of an efficient methodology to assess the phytase-producing micro-organisms. In this study, a method to assess beta-propeller phytase (BPP)-carrying bacteria in soil was validated. This method may contribute to the knowledge of how these micro-organisms behave in the environment and contribute for plant growth promotion.
authors.affiliation: Department of Soil Science, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Piracicaba, SP, Brazil.|Department of Microbial Ecology, GELIFES, University of Groningen, Groningen, The Netherlands.
authors.forename: S R
authors.initials: SR
authors.lastname: Cotta
authors.affiliation: Department of Soil Science, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Piracicaba, SP, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Cavalcante Franco Dias
authors.affiliation: Institute of Microbiology Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Seldin
authors.affiliation: Department of Soil Science, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Piracicaba, SP, Brazil.
authors.forename: F D
authors.initials: FD
authors.lastname: Andreote
authors.affiliation: Department of Microbial Ecology, GELIFES, University of Groningen, Groningen, The Netherlands.
authors.forename: J D
authors.initials: JD
authors.lastname: van Elsas
mesh_terms: D010832:6-Phytase / Q000235:genetics*; D034241:Alteromonadaceae / Q000201:enzymology / Q000235:genetics*; D001938:Brazil; D016934:Caulobacter / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D010758:Phosphorus / Q000378:metabolism; D010802:Phylogeny; D010833:Phytic Acid / Q000378:metabolism; D011549:Pseudomonas / Q000201:enzymology / Q000235:genetics*; D058441:Rhizosphere; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D003313:Zea mays / Q000382:microbiology*
chemical_list: D012987:Soil; D010758:Phosphorus; D010833:Phytic Acid; D010832:6-Phytase
keywords: BPP-like genes; diversity of β-propeller phytases genes; maize rhizosphere; microbial structure; organic phosphorus mineralization