title: Screening of Brazilian cacti rhizobacteria for plant growth promotion under drought.
abstract: Drought is one of the major problems worldwide. The search for new and efficient microorganisms, from unexplored environments, to be used in association with plants to alleviate the negative effects imposed by water stress, is an interesting alternative. Thus, cacti-associated bacteria from the Brazilian semi-arid region were isolated based on their ability to grow in medium with reduced water availability. Strains were tested for the production of exopolysaccharides (EPS), as well as in vitro plant growth promotion traits. A great proportion of the isolates belong to the genus Bacillus. From a total of forty-eight bacteria, 65% were able to grow in medium with reduced water availability (0.919Aw), exopolysaccharide production was observed for 65% of the strains. The production of indole acetic acid (IAA) exceeding 51μgmL(-1) was observed for 4% and the high solubilization of Ca-P was verified for 6% of the isolates. No strain was able to produce hydrogen cyanide (HCN), 71% produced ammonia and 79% showed a halo of carboxymethyl cellulose (CMC) degradation. Zea mays L. growth promotion under water stress (30% of field capacity) was achieved by two strains of Bacillus spp. This is the first report to describe cacti-associated bacteria from Brazilian semi-arid with plant growth-promoting abilities.
authors.affiliation: Laboratory of Environmental Microbiology, Embrapa Environment, P.O. Box 69, Jaguariúna, SP 13820-000, Brazil. van_nessner@yahoo.com.br
authors.forename: Vanessa Nessner
authors.initials: VN
authors.lastname: Kavamura
authors.forename: Suikinai Nobre
authors.initials: SN
authors.lastname: Santos
authors.forename: João Luiz da
authors.initials: JL
authors.lastname: Silva
authors.forename: Márcia Maria
authors.initials: MM
authors.lastname: Parma
authors.forename: Luciana Aparecida
authors.initials: LA
authors.lastname: Avila
authors.forename: Alexandre
authors.initials: A
authors.lastname: Visconti
authors.forename: Tiago Domingues
authors.initials: TD
authors.lastname: Zucchi
authors.forename: Rodrigo Gouvêa
authors.initials: RG
authors.lastname: Taketani
authors.forename: Fernando Dini
authors.initials: FD
authors.lastname: Andreote
authors.forename: Itamar Soares de
authors.initials: IS
authors.lastname: Melo
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001938:Brazil; D029421:Cactaceae / Q000382:microbiology*; D055864:Droughts; D006856:Hydrogen Cyanide / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000378:metabolism*; D014867:Water / Q000378:metabolism; D003313:Zea mays / Q000254:growth & development* / Q000382:microbiology
chemical_list: D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D014867:Water; D006856:Hydrogen Cyanide; C030737:indoleacetic acid; D000641:Ammonia