Phosphorus-Solubilizing Capacity of Mortierella Species Isolated from Rhizosphere Soil of a Poplar Plantation

Abstract

Phosphorus is one of the main nutrients necessary for plant growth and development. Phosphorus-dissolving microorganisms may convert insoluble phosphorus in soil into available phosphorus that plants can easily absorb and utilize. In this study, four phosphorus-solubilizing fungi (L3, L4, L5, and L12) were isolated from the rhizosphere soil of a poplar plantation in Dongtai, Jiangsu Province, China. Phylogenetic analysis based on the internal transcribed spacer (ITS) and large subunit (LSU) of the ribosomal DNA sequences showed that the ITS and 28S sequences of isolates were the most similar to those of Mortierella. Morphological observation showed that most colonies grew in concentric circles and produced spores under different culture conditions. These results and further microscopic observations showed that these isolated fungi belonged to the genus Mortierella. Pikovskaya (PKO) medium, in which tricalcium phosphate was the sole phosphorus source, was used to screen strain L4 with the best phosphorus-solubilizing effect for further study. When the carbon source was glucose, the nitrogen source was ammonium chloride, the pH was 5, and the available phosphorus content was the highest. By exploring the possible mechanism of phosphorus release by phosphorus-solubilizing fungi, it was found that strain L4 produces several organic acids, such as oxalic acid, lactic acid, acetic acid, succinic acid, tartaric acid, malic acid, and citric acid. At 24 h, the alkaline phosphatase and acid phosphatase activities reached 154.72 mol/(L·h) and 120.99 mol/(L·h), respectively.

Improvement in Wheat Productivity with Integrated Management of Beneficial Microbes along with Organic and Inorganic Phosphorus Sources

“…The beneficial effect of organic manures in combination was also observed by [21]. The results are also consistent with those of [36], who reported that the application of PSB increased the nutrient availability to the plant, which increased the plant growth and yield.…”

Phosphate-Solubilizing Capacity of Paecilomyces lilacinus PSF7 and Optimization Using Response Surface Methodology

“…In the research of inorganic nitrogen sources on the phosphate-solubilizing capacity of PSMs, ammonium was found to be a better nitrogen sources than nitrate. Sang et al [ 61 ] found that strain L4 had the highest phosphorus-solubilizing content when ammonium sulfate was used as the nitrogen sources. The research of Sulbaran et al [ 91 ] research found that the pH value of the fermentation broth of P. agglomerates MMB051 in the presence of KNO 3 was 5.10 ± 0.15, while, when the nitrogen sources was changed to (NH 4 ) 2 SO 4 , the pH value of the fermentation broth was 2.86 ± 0.21 and the content of the soluble phosphorus related to the change of pH value also changed.…”

“…The sequences were input into the National Center for Biotechnology Information (NCBI) ( , accessed on 10 December 2022) database of the United States National Center for Biotechnology Information and were compared with the sequences in the Genbank database using the BLAST algorithm. Clustal_X was used to accomplish the sequence alignment and Mega 6.0 software was used to construct a neighbor-joining-based phylogenetic tree [ 61 ].…”

“…At the same time, the same medium without PSF7 was used as a control. The culture supernatant was collected every day to evaluate the pH and the soluble phosphorus content [ 61 ]. The pH of the supernatants was directly measured using a pH meter (VSTAR10, Thermo Fisher, Waltham, MA, USA).…”

Analysis of rhizosphere fungal community of agricultural crops cultivated in laboratory experiments on Chernevaya taiga soil

“…It was demonstrated that most of the species of this genus are able to produce and accumulate in the mycelium polyunsaturated fatty acids (arachidonic, γ-linolenic, eicosapentaenoic, and docosahexaenoic), which are involved in the induction of resistance to phytopathogens in plants of agricultural importance (Zlotek and Wójcik 2014). Another important feature of Mortierell a is phosphorus-solubilizing capacity due to the production of several organic acids (Sang et al 2022). Recent studies revealed other features of Mortierella as PGPF, such as the production of phytoregulators (IAA, gibberellic acid, ACC deaminase), siderophores production, strong cellulolytic and chitinolytic activity, protease and urease activity, etc.…”