Identification and characterization of inorganic-phosphate-solubilizing bacteria from agricultural fields with a rapid isolation method
Bang-Xiao Zheng,
Muhammad Ibrahim,
Ding-Peng Zhang,
Qing-Fang Bi,
Hong-Zhe Li,
Guo-Wei Zhou,
Kai Ding,
Josep Peñuelas,
Yong-Guan Zhu,
Xiao-Ru Yang
Affiliations
Bang-Xiao Zheng
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences
Muhammad Ibrahim
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences
Ding-Peng Zhang
State Key Laboratory of Biocontrol, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institutes, College of Ecology and Evolution, Sun Yat-sen University
Qing-Fang Bi
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences
Hong-Zhe Li
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences
Guo-Wei Zhou
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences
Kai Ding
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences
Josep Peñuelas
Consejo Superior de Investigaciones Científicas (CSIC), Global Ecology Unit, Centre for Ecological Research and Forestry Applications (CREAF), Universitat Autònoma de Barcelona (UAB)
Yong-Guan Zhu
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences
Xiao-Ru Yang
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences
Abstract The ability to solubilize fixed inorganic phosphorus (P) for plant growth is important for increasing crop yield. More P can be released by inoculating soil with inorganic-phosphate-solubilizing bacteria (iPSBs). We used 96-well microplates instead of traditional 200-mm petri dishes to rapidly screen iPSB strains for their solubilizing ability. We simultaneously obtained 76 iPSB isolates from 576 wells containing two agricultural soils. This method conveniently identified positive iPSB strains and effectively prevented fungal cross-contamination. Maximum-likelihood phylogenetic trees of the isolated strains showed that Bacillus megaterium was the most dominant iPSB, and strains Y99, Y95, Y924 and Y1412 were selected as representatives for the analysis of P solubilization. Succinic acid was the main organic acid of B. megaterium for releasing P. It was strongly correlated with the increase in soluble P concentration during 168 h of incubation of these four strains. pH was negatively exponentially correlated with the amount of soluble P in the medium, and the amount of succinic acid was strongly linearly correlated with the amount of P released (P < 0.001), suggesting that organic acid may mobilize microbial P. Our study provides an efficient and effective method for identifying and analyzing the growth of iPSB strains able to solubilize inorganic P and gives a better understanding of the mechanism of P solubilization.
