Strategies of organic phosphorus recycling by soil bacteria: acquisition, metabolism, and regulation

Abstract

Summary Critical to meeting cellular phosphorus (P) demand, soil bacteria deploy a number of strategies to overcome limitation in inorganic P (Pi) in soils. As a significant contributor to P recycling, soil bacteria secrete extracellular enzymes to degrade organic P (Po) in soils into the readily bioavailable Pi. In addition, several Po compounds can be transported directly via specific transporters and subsequently enter intracellular metabolic pathways. In this review, we highlight the strategies that soil bacteria employ to recycle Po from the soil environment. We discuss the diversity of extracellular phosphatases in soils, the selectivity of these enzymes towards various Po biomolecules and the influence of the soil environmental conditions on the enzyme's activities. Moreover, we outline the intracellular metabolic pathways for Po biosynthesis and transporter‐assisted Po and Pi uptake at different Pi availabilities. We further highlight the regulatory mechanisms that govern the production of phosphatases, the expression of Po transporters and the key metabolic changes in P metabolism in response to environmental Pi availability. Due to the depletion of natural resources for Pi, we propose future studies needed to leverage bacteria‐mediated P recycling from the large pools of Po in soils or organic wastes to benefit agricultural productivity.

In-depth characterization of phytase-producing plant growth promotion bacteria isolated in alpine grassland of Qinghai-Tibetan Plateau

“…The 16S rDNA sequencing analysis suggested 73 phytase-producing bacteria isolates grouped into two phyla which consisted of 16 different genera. Proteobacteria (90.41%) was the most dominant, including Pseudomonas, Acinetobacter, Variovorax, Achromobacter, Pantoea, Arthrobacter, etc., and more than 49% (36) of isolates belongs to Pseudomonas, which also confirmed that the γ-Proteobacteria was the main bacterial group producing phytase, as reported by Park et al (2022). In addition, we compared the extracellular phytase activity between genera of Pseudomonas and others to confirm the dominant genus, and the results indicated that isolates of Pseudomonas in the present work had a higher average activity, which could be representative within strains colonized in grass rhizosphere in the soils studied.…”

Substitution of manure for mineral P fertilizers increases P availability by enhancing microbial potential for organic P mineralization in greenhouse soil

“…Through functional prediction (using PICRUSt2), 38 genes involved in P transformation were detected ( Park et al, 2022 ). PoR treatment significantly decreased the abundance of the phoU and pst genes, while it significantly increased the abundance of the phoR and phnA genes and genes coding for alkaline phosphatase and C-P lyase ( Figure 2A ).…”

Maize-soybean intercropping facilitates chemical and microbial transformations of phosphorus fractions in a calcareous soil

“…Maize-soybean intercropping could increase soil P availability through multiple mechanisms including root exudates and proton-induced dissolution of P-containing minerals, increased phosphatase activity, and functional microbe-mediated P i mobilization and P o mineralization ( Hinsinger, 2001 ; Betencourt et al, 2012 ; Amadou et al, 2021 ; Park et al, 2022 ). In this study, rhizospheric OC content significantly increased for both crops under the NB treatment relative to the SB treatment ( Table 2 ), which reflected the accumulation of rhizosphere OC under the NB treatment.…”

“…For the cycling of P o pools, enzymes serve as one of the major driving factors to mineralize P o into the available P i pool for crop uptake ( Richardson et al, 2009 ; Park et al, 2022 ; Yu et al, 2022 ). Generally, the ALP in soils is considered as microbial origin, while the PDE could be from plant roots and microbes ( Amadou et al, 2021 ).…”