Solubilization ability of Rahnella sp. W25 under buffering condition and its acetic-producing characteristics

Abstract:

[Objective] Objectives of this study were to further understand the mechanism on phosphate solubilization of Rahnella sp. W25 and its solubilization ability under buffering condition. [Methods] Regulating pH of nutrient solution was conducted in the process of liquid shake flask culture to research the influence of buffer capacity on the phosphate solubilizing ability of Rahnella sp. W25 under simulation soil condition. Research the solubilizing ability and acetic-producing characteristics under different carbon and phosphorus sources condition though single factor text and HPLC. [Results] The result showed that the available phosphorus content reached up to its maximum after cultivated 120 h in the solution of tricalcium phosphate. The change of available phosphorus content and pH in solution showed significant negative correlation (P<0.01). At cultivated 48?96 h, strain W25 had stronger buffering capacity and the difference of available phosphorus content between regulating pH using and without using NaOH was not significant (P<0.05). Strain W25 weaken after cultivated 120 h and basically lost buffering capacity after cultivated 168 h. The solubilizing ability showed significant different under different carbon sources (P<0.05). The order of solubilization ability as follows: glucose>lactose>sucrose>mannitol>starch. It also showed extremely significant different under different phosphorus sources (P<0.01). The order was tricalcium phosphate>iron phosphate>aluminum phosphate>ground phosphate rock. The type and concentration of organic acids were dissimilar under different carbon and phosphorus sources conditions. The solubilization ability of strain W25 was both related to the type and concentration of organic acids. [Conclusion] Results of this study could provide the condition of deeply researching mechanism on phosphate solubilization and the theoretical basis of application of Rahnella sp..

Key words:Rahnella sp., Phosphate solubilization ability, Buffering capacity, Carbon, Phosphorus, Acetic-producing characteristics