title: Maize endophytic bacteria as mineral phosphate solubilizers.
abstract: In the present study, we demonstrated the in vitro activity of endophytic phosphate-solubilizing bacteria (PSB). Fifty-five endophytic PSB that were isolated from sap, leaves, and roots of maize were tested for their ability to solubilize tricalcium phosphate and produce organic acid. Partial sequencing of the 16S rRNA-encoding gene showed that the isolates were from the genus Bacillus and different species of Enterobacteriaceae. The phosphate solubilization index on solid medium and phosphate solubilization in liquid medium varied significantly among the isolates. There was a statistically significant difference (P ≤ 0.05) for both, the values of phosphate-solubilizing activity and pH of the growth medium, among the isolates. Pearson correlation was statistically significant (P ≤ 0.05) between P-solubilization and pH (R = -0.38), and between the gluconic acid production and the lowering of the pH of the liquid medium at 6 (R = 0.28) and 9 days (R = 0.39). Gluconic acid production was prevalent in all the PSB studied, and Bacillus species were most efficient in solubilizing phosphate. This is the first report on the characterization of bacterial endophytes from maize and their use as potential biofertilizers. In addition, this may provide an alternative strategy for improving the phosphorus acquisition efficiency of crop plants in tropical soils.
authors.affiliation: Programa de Pós-Graduação em Ciências Agrárias, Departamento de Ciências Agrárias, Universidade Federal de São João Del Rei, Sete Lagoas, MG, Brasil.
authors.forename: C S
authors.initials: CS
authors.lastname: de Abreu
authors.affiliation: Laboratório de Microbiologia e Biologia Molecular, Embrapa Milho e Sorgo, Sete Lagoas, MG, Brasil.
authors.forename: J E F
authors.initials: JE
authors.lastname: Figueiredo
authors.affiliation: Laboratório de Microbiologia e Biologia Molecular, Embrapa Milho e Sorgo, Sete Lagoas, MG, Brasil.
authors.forename: C A
authors.initials: CA
authors.lastname: Oliveira
authors.affiliation: Laboratório de Microbiologia e Biologia Molecular, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
authors.forename: V L
authors.initials: VL
authors.lastname: Dos Santos
authors.affiliation: Laboratório de Microbiologia e Biologia Molecular, Embrapa Milho e Sorgo, Sete Lagoas, MG, Brasil.
authors.forename: E A
authors.initials: EA
authors.lastname: Gomes
authors.affiliation: Programa de Pós-Graduação em Ciências Agrárias, Departamento de Ciências Agrárias, Universidade Federal de São João Del Rei, Sete Lagoas, MG, Brasil.
authors.forename: V P
authors.initials: VP
authors.lastname: Ribeiro
authors.affiliation: Laboratório de Microbiologia e Biologia Molecular, Embrapa Milho e Sorgo, Sete Lagoas, MG, Brasil.
authors.forename: B A
authors.initials: BA
authors.lastname: Barros
authors.affiliation: Laboratório de Microbiologia e Biologia Molecular, Embrapa Milho e Sorgo, Sete Lagoas, MG, Brasil.
authors.forename: U G P
authors.initials: UG
authors.lastname: Lana
authors.affiliation: Programa de Pós-Graduação em Ciências Agrárias, Departamento de Ciências Agrárias, Universidade Federal de São João Del Rei, Sete Lagoas, MG, Brasil ivanildo.marriel@embrapa.br.|Laboratório de Microbiologia e Biologia Molecular, Embrapa Milho e Sorgo, Sete Lagoas, MG, Brasil ivanildo.marriel@embrapa.br.
authors.forename: I E
authors.initials: IE
authors.lastname: Marriel
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D060026:Endophytes / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D005942:Gluconates / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism*; D010802:Phylogeny; D018515:Plant Leaves / Q000382:microbiology; D018517:Plant Roots / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D003313:Zea mays / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005942:Gluconates; D010710:Phosphates; D012336:RNA, Ribosomal, 16S; C030691:gluconic acid