Effect of pH and Carbon Source on Phosphate Solubilization by Bacterial Strains in Pikovskaya Medium

• Published in: Microorganisms (Basel) Vol. 11; no. 1; p. 49
• Main Authors: Sanchez-Gonzalez, Ma Esther, Mora-Herrera, Martha E, Wong-Villarreal, Arnoldo, De La Portilla-López, Nadia, Sanchez-Paz, Laura, Lugo, Jorge, Vaca-Paulín, Rocio, Del Aguila, Pedro, Yañez-Ocampo, Gustavo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 23-12-2022; MDPI
• Subjects: Bacillus pumilus; Bacillus siamensis; Bacteria; biofertilizer; Biofertilizers; Biomass; Calcium phosphates; Carbon; Carbon sources; Culture media; Experiments; Gene sequencing; Glucose; Iron phosphates; Orthophosphates; pH effects; Phosphorus; Pikovskaya medium; Pseudomonas; Pseudomonas libanensis; rRNA 16S; Solubilization; soluble phosphorus; Strains (organisms); Sucrose; Tricalcium phosphate; United States > US; Mexico; biofertilizer; Bacillus pumilus; soluble phosphorus; Pikovskaya medium; sucrose
• ISSN: 2076-2607; 2076-2607
• DOI: 10.3390/microorganisms11010049

Phosphate-solubilizing bacteria (PSB) transform precipitated inorganic phosphorus into soluble orthophosphates. This study evaluated the efficiency of tricalcium and iron phosphate solubilization in Pikovskaya medium using five bacterial strains (A1, A2, A3, A5, and A6) cultured in acidic and alkaline pH levels. The bacterial strain that proved to be more efficient for P solubilization and was tolerant to pH variations was selected for assessing bacterial growth and P solubilization with glucose and sucrose in the culture medium. The bacterial strains were identified through 16S rRNA gene sequencing as
A1,
(A2),
(A3),
(A5), and
(A6). These five bacterial strains grew, tolerated pH changes, and solubilized inorganic phosphorus. The bacterial strain A3 solubilized FePO
(4 mg L
) and Ca
(PO
)
(50 mg L
). P solubilization was assayed with glucose and sucrose as carbon sources for A3 (
MN100586). After four culture days, Ca
(PO
)
was solubilized, reaching 246 mg L
with sucrose in culture media. Using glucose as a carbon source, FePO
was solubilized and reached 282 mg L
in six culture days. Our findings were:
, and
as new bacteria, can be reported as P solubilizers with tolerance to acidic or alkaline pH levels. The bacterial strain
grew using two sources of inorganic phosphorus and carbon, and it tolerated pH changes. For that reason, it is an ideal candidate for inorganic phosphorus solubilization and future production as a biofertilizer.