Öğüt, MehmetEr, FatihKandemir, Nejdet2020-03-262020-03-262010Öğüt, M., Er, F., Kandemir, N., (2010). Phosphate Solubilization Potentials of Soil Acinetobacter Strains. Biology and Fertility of Soils, (46), 707-715. Doi: 10.1007/s00374-010-0475-70178-27621432-0789https://dx.doi.org/10.1007/s00374-010-0475-7https://hdl.handle.net/20.500.12395/25153Many phosphate solubilizing microorganisms (PSM) require external pyrroloquinoline quinone (PQQ) for strong phosphorus (P) solubilization in vitro. The objective of this study was to isolate efficient and PQQ-independent PSM. A total of 21 PSM were isolated from the rhizosphere soil of wheat and maize grown in the pots. Acinetobacter strains were the only PQQ-independent and most effective solubilizers of tricalcium phosphate containing agar. The mean P dissolved in liquid cultures of Acinetobacter strains in a 5-day incubation ranged from 167 to 888 mu g/ml P. The pH dropped to below 4.7 from 7.8 in six isolates, which produced gluconic acid in concentrations ranging between 27.5 and 37.5 mM. There was a linear regression between soluble P and gluconic acid concentrations in the bacterial cultures (P < 0.05; R (2) = 0.59). Inoculation with Acinetobacter sp. WR922 significantly (P < 0.05) increased wheat (Triticum aestivum L.) P content by 27% at 15 days after emergence (DAE) and dry matter by 15% at 30 DAE compared to the control. The plant P content in inoculated plants at 30 DAE was linearly correlated with soluble P of the bacterial cultures (P < 0.05; R (2) = 0.69). Gluconic acid production directly affected phosphate solubilization in vitro, which in turn influenced plant P content of inoculated plants in PQQ-independent P-solubilizing Acinetobacter strains.en10.1007/s00374-010-0475-7info:eu-repo/semantics/openAccessPhosphate solubilizationPyrroloquinoline quinone (PQQ)AcinetobacterArticle46707715Q1WOS:000280783700006Q1