Isolation, Mutagenesis, and Organic Acid Secretion of a Highly Efficient Phosphate-Solubilizing Fungus

Abstract

The highly effective phosphate-solubilizing microorganisms are significant for making full use of the potential phosphorus resources in the soil and alleviating the shortage of phosphorus resources. In this study, a phosphate-solubilizing fungus was isolated from wheat and cotton rhizosphere soils in the lower reaches of the Yellow River in China and was identified as Penicillium oxalicum by morphological and ITS sequencing analysis. In order to obtain a fungus with more efficient phosphorus solubilization ability, we tested three positive mutant strains (P1, P2, and P3) and three negative mutant strains (N1, N2, and N3) through low-energy nitrogen ion implantation mutagenesis. Compared with the parental strain, the phosphate-solubilizing capacity of P1, P2, and P3 was enhanced by 56.88%, 42.26%, and 32.15%, respectively, and that of N1, N2, and N3 was weakened by 47.53%, 35.27%, and 30.86%, respectively. Compared with the parental strain, the total amount of organic acids secreted significantly increased in the three positive mutant strains and decreased in the negative mutant strains; the pH of culture medium was significantly lower in the positive mutant strains and higher in the negative mutant strains. The capacity of phosphate-solubilizing fungus to secrete organic acids and reduce the growth-medium pH was closely related to its phosphate-solubilizing ability. The changes in the amount of organic acids secreted by mutants can alter their acidification and phosphate-solubilizing capacity. In conclusion, this study offers a theoretical basis and strain materials for the exploration and application of phosphate-solubilizing fungi.

Studies on the Phosphorus-Solubilizing Ability of Isaria cateinannulata and Its Influence on the Growth of Fagopyrum tataricum Plants

“…This is because 1/7 of the metabolites produced by I. cateinannulata are acidic organic compounds. Different strains secrete different types, amounts, and concentrations of organic acids during their growth, leading to different degrees of pH decline in the culture medium [61,62]. After 10 days of continuous cultivation, the pH of 18 strains of I. cateinannulata showed varying degrees of decline (Figure 2c).…”

Focus and Insights into the Synthetic Biology-Mediated Chassis of Economically Important Fungi for the Production of High-Value Metabolites

“…Random mutagenesis was attempted in fungi for the enhanced yield of polyamines [ 149 ]. Yang and coworkers [ 150 ] employed mutagenesis in Penicillium oxalicum , phosphate-solubilizing fungi for improved production of organic acid and phosphate solubilization, respectively, which increased significantly on mutagenesis by radiation. In addition, physical and chemical mutagens were used to produce high-value metabolites from fungi, aimed toward a bio-based economy.…”

Increasing the Bioavailability of Phosphate by Using Microorganisms

“…quencing technique is used to characterize and identify the exact bacterial species [3,21,23,31,41], and ITS sequence analysis is used for the characterization of fungal species [68] of PSM. Universal primers are used for the gene amplifcation [3,39].…”