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The utilization of phosphate-solubilizing bacteria (PSB) in agriculture has long been proposed as an eco-friendly method to enhance soil phosphorus (P) availability, thereby reducing reliance on chemical P fertilizers. However, their application in saline soils is challenged by salt-induced stress on common PSB strains. In this study, we sourced bacterial strains from marine environments, aiming to identify robust PSB strains adaptable to saline conditions and assess their potential as P bio-fertilizers through a microcosm experiment. Our findings indicate that the inoculation of a selected marine PSB, Bacillus paramycoides 3-1a, increased soil available P content by 12.5% when applied alone and by 61.2% when combined with organic amendments. This enhancement results from improved inorganic P solubilization and organic P mineralization in soils. Additionally, these treatments raised soil nitrogen levels, reshaped microbial community structures, and significantly enhanced wheat (Triticum aestivum L.) growth, with P accumulation increasing by 24.2-40.9%. Our results underscore the potential of marine PSB in conjunction with organic amendments for the amelioration of saline agricultural soils., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The challenge of managing agricultural phosphorus (P) in saline regions entails both reducing leaching for environmental protection and maintaining soil available P levels for crop production, which could be achieved through functional microorganisms that can facilitate P transformation processes like P assimilation, inorganic P solubilization, and organic P mineralization. In this study, we proposed an integrated utilization of phosphorus-accumulating bacteria (PAB) and phosphorus-solubilizing bacteria (PSB) to reach the goal of alleviating P leaching while improving soil available P levels. The study conducted a microcosm experiment that combined a soil column test, soil incubation, and pot experiment to evaluate the effect of bacterial inoculants on soil P leaching, soil P availability, and plant P accumulation. The results showed that the application of PAB reduced 22.6 % of dissolved P leaching through the absorption of labile phosphate in the soil, and 17.3 % of particulate P leaching through the promoted soil aggregation. The integrated inoculation of PSB and PAB synergistically improved soil available P content by 18.3 % through the mineralization of soil organic P, and remarkably boosted wheat growth and its P accumulation. Microbial community analysis revealed that the integrated microbial treatment decreased the diversity of soil bacterial community and increased the abundance of native microbial species, i.g. Lysobacter and Ramlibacter, which were positively correlated with soil available P content and alkaline phosphatase level. In conclusion, the integrated microbial strategy based on halotolerant PAB and PSB has great potential for sustainable P management in saline areas and agricultural activities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Marine bacteria play indispensable roles in the phosphorus (P) cycle, primarily responsible for P assimilation and remineralization. The aim of this study was to determine diversity of marine aerobic bacteria from the South China Sea capable of P immobilization. Highly efficient P immobilized genera reached 87.72% of all genera, which were mainly distributed in epipelagic seawater zone and semi-deep sediment zone. Accumulated P in extracellular polymeric substances (EPS) accounted for about 70% of immobilized P of representative bacteria. The sum of bioavailable P (non-apatite inorganic phosphorus, organic phosphorus) amounted to more than 90% of total P in representative bacteria, and orthophosphate monoester was identified as the only extracellular P species. Marine bacteria which participated in P cycle were general, not specific genus. EPS of marine bacteria played an important role in P immobilization, and accumulated P species were bioavailable. Our results may provide a better insight for understanding roles of marine bacteria in P cycle.

As one solid waste with potential for phosphorus removal, application of slags in water treatment merits attention. But it was inhibited greatly by alkaline solution (pH>9.5) and cemented clogging generated. To give one solution, phosphorus removal was investigated by combining deep-sea bacterium Alteromonas 522-1 and basic oxygen furnace slag (BOFS). Results showed that by the combination, not only higher phosphorous removal efficiency (>90%) but also neutral solution pH of 7.8-8.0 were achieved at wide ranges of initial solution pH value of 5.0-9.0, phosphorus concentration of 5-30mg/L, salinity of 0.5-3.5%, and temperature of 15-35°C. Moreover, sedimentary property was also improved with lower amount of sludge production and alleviated BOFS cementation with increased porosity and enlarged particle size. These results provided a promising strategy for the phosphorus recovery with slags in large-scale wastewater treatment., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

BACKGROUND Seeking efficient phosphorus (P) removal methods is of great significance in both aspects of environmental protection and resource conservation. Silicon (Si) is always present in marine sediments and it contributes significantly to P removal by iron (Fe( III)) oxides. Marine microbes play the major role in marine biomineralization. The aim of this study was to investigate P removal performance by marine bacterium enhanced with Fe ( III) in the presence of Si and the role Si played in the system. RESULTS The optimal Fe/Si/P molar ratio for P removal was 1:1.5:1. P removal efficiency was 47.79%, 96.02%, and 97.87% in systems of pure bacterial cultures, bacteria with Fe ( III), and bacteria with Fe ( III) and Si, respectively, at P of 30 mg L−1. Flocs and micro-precipitates were formed around cells in P removal systems containing Fe ( III) or Si. Moreover, the amount and size of flocs in systems containing Si were larger than those without Si. CONCLUSION P removal by marine bacterium enhanced with Fe ( III) had good performance through precipitation and adsorption. Si was able to strengthen P removal ability and sludge settleability. This study can provide us with new insights into bacterial induced metal phosphate precipitate and into the marine P cycle. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Excessive release of phosphorus (P) from wastewater into water systems is a significant environmental problem. Aerobic P removal, a new P removal pathway, was investigated. P removal primary mechanisms of marine bacteria Shewanella sp. CF8-6 ( S . sp. CF8-6) were studied by batch tests and characterization analysis. The strain showed wide environmental adaptability (temperature 5.0–35.0 °C, dissolved oxygen (DO) 5.2–8.6 mg/L, pH 5.8–9.6, salinity 0.0–10.0%, P concentration 1.1–11.7 mg/L and COD/N (C/N) 7–13) and a relatively high P removal performance under strict aerobic conditions. The optimum conditions of P removal by S . sp. CF8-6 was: temperature 25.0 °C, DO 7.83 mg/L, pH 7.2, salinity 5.0%, P concentration 11.74 mg/L and C/N 13. The higher P removal rate was associated with better biomass growth of S . sp. CF8-6 in general, but the strategy of biomass-independent P removal was also indicated. Only a small percentage (20.0%) of removed P contributed by bacterial growth and intracellular metabolism, while a considerable part (up to 60%) was reserved in extracellular polymeric substances (EPS) in the form of extracellular phospholipid nanoparticles. The scanning electron microscope-energy dispersive spectrometer (SEM-EDS) results indicated the element in the accumulation nanoparticles was carbon, oxygen, sodium and P. The 31 P nuclear magnetic resonance (NMR) analysis illustrated that orthophosphate monoester was the only intracellular P species, while both orthophosphate monoester and diesters existed extracellularly. Batch treatment of actual wastewater showed S . sp. CF8-6 had application potential in saline wastewater treatment. This study introduced a new pathway of P accumulation and removal. Application of marine bacteria S . sp. CF8-6 provided us an alternative method for P removal, especially in saline wastewater. [ABSTRACT FROM AUTHOR]

In saline-alkali soils, the inactivation of phosphorus and loss of nitrogen resulting in soil infertility could be intensified by salt, which simultaneously leads to pollution of water sphere. However, there is no complete solution for this challenge due to the weak nutrients biological turnover caused by salt dynamic accumulation. In this study, halophilic marine bacteria strains with carriers were screened to decrease the leaching of nitrogen and phosphorus inactivation in saline-alkali soil during salt-washing. Results showed the combination of Pseudoalteromonas sp. CF8-6 and corn cob significantly increased not only soil available phosphorus by 37.03%, but also the soil bioavailable phosphorus content. Moreover, the concentration of TN, NO 3 −, TP and PO 4 3− in salt washing eluents reduced by corn cob colonized with CF8-6 significantly. It was also found that the abundance of nitrogen-fixing bacteria (such as Azotobacter), and abundance of Proteobacteria and Actinobacteria in soil were all increased by this combination, which were corresponding for the turnover of nitrogen and phosphorus. We demonstrated that the combination of CF8-6 and corn cob has promising potential in improvement of bioavailability of soil nitrogen and phosphorus during the salt-washing process in saline-alkali soil. • CF8-6 and corn cob increased bioavailable phosphorus content in saline-alkali soil. • Soil microbiological properties had been changed by CF8-6 and corn cob addition. • Marine bacterium combined with straw can be potential saline-alkali soil amendments. [ABSTRACT FROM AUTHOR]