Regulation of Soluble Phosphate on the Ability of Phytate Mineralization and β-Propeller Phytase Gene Expression of Pseudomonas fluorescens JZ-DZ1, a Phytate-Mineralizing Rhizobacterium

Curr Microbiol. 2016 Dec;73(6):915-923. doi: 10.1007/s00284-016-1139-0. Epub 2016 Sep 24.

Abstract

Phytate-mineralizing rhizobacteria (PMR) play an important role in providing phosphorus for the sustainable plant growth. It is important to investigate the ability of PMR to produce phytase under different phosphate levels for its application. The effects of different concentrations of soluble phosphate on the ability of phytate mineralization of Pseudomonas fluorescens JZ-DZ1, a phytate-mineralizing rhizobacterium, were investigated in both solid and liquid media. The results on solid media showed that halo zone width gradually reduced with concentrations of soluble phosphate increasing from 0.05 to 20 mM, indicating the reduction of the ability of phytate mineralization. The results were consistent with the quantitative detection of phytase activity from the overall trend. An 1866-bp β-propeller phytase (BPP) gene (phyPf) was cloned from the strain, and the deduced amino acid sequence of phyPf shared 98 % of identity with a known BPP from Pseudomonas sp. BS10-3 (AJF36073.1). The results of relative real-time quantitative PCR assay showed that the expression of phyPf was induced by a low concentration (0.1 mM) of soluble phosphate, suggesting that BPP secretion was regulated by gene phyPf. The BPP-harboring bacterium P. fluorescens JZ-DZ1 with low phosphate-inducible ability of phytate mineralization could be potentially applied to promote phosphorus uptake for plants in the future.

MeSH terms

  • 6-Phytase / chemistry
  • 6-Phytase / genetics
  • 6-Phytase / metabolism*
  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Gene Expression Regulation, Bacterial
  • Gene Expression Regulation, Enzymologic*
  • Molecular Sequence Data
  • Phosphates / metabolism
  • Phylogeny
  • Phytic Acid / metabolism*
  • Pseudomonas fluorescens / enzymology*
  • Pseudomonas fluorescens / genetics
  • Pseudomonas fluorescens / metabolism
  • Sequence Alignment

Substances

  • Bacterial Proteins
  • Phosphates
  • Phytic Acid
  • 6-Phytase