New Insight into Carboxylic Acid Metabolisms and pH Regulations During Insoluble Phosphate Solubilisation Process by Pen
- PDF / 2,772,736 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 21 Downloads / 193 Views
New Insight into Carboxylic Acid Metabolisms and pH Regulations During Insoluble Phosphate Solubilisation Process by Penicillium oxalicum PSF‑4 Yifan Jiang1 · Jiang Tian1 · Fei Ge1 Received: 23 December 2019 / Accepted: 1 October 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract Phosphate solubilising fungi (PSF) play an important role in increasing phosphorus (P) bioavailability and the fertility of soil. However, the mechanism by which PSF solubilise insoluble P using carboxylic acid is not fully understood. In this study, Penicillium oxalicum PSF-4 was isolated and shown to have satisfactory solubilisation performance towards tricalcium phosphate (TP) and iron phosphate (IP). In treatments with TP or IP, the soluble P (Psol) concentrations were positively correlated with the carboxyl groups in organic acids but negatively correlated with the pKsp of insoluble P sources and pH. Additionally, the compositions of the organic acids (considering the lowest pKa value for acids with several pKas) were remarkably different between the treatments: oxalic (pKa = 1.27), malic (pKa = 3.46), and formic (pKa = 3.75) acids in TP treatments (maximum 381 mg/L); and lactic (pKa = 3.85), gluconic (pKa = 3.86), and citric (pKa = 3.12) acids in IP treatments (maximum 1634 mg/L). The addition of H + without P. oxalicum PSF-4 inoculation markedly improved Psol concentrations. The above results offer new insights that the pKsp of P sources, compositions of carboxylic acids, and pH regulation are the key factors influencing P solubilisation of different insoluble P sources.
Introduction Phosphorus (P) is critical for plant growth and development, but most is unavailable in the soil or transported to the ocean due to an incomplete P cycle [1]. Although total P in soils is usually relatively high, 0.10–0.15%, P is often the limiting factor for plant growth because of its low bioavailability [2]. In fact, most P in soil is immobilized in Ca3(PO4)2 (ksp = 2.1 × 10–33), FePO4 (ksp = 1.3 × 10–22), or AlPO4 (ksp = 5.8 × 10–19), forms which plants cannot utilize [3]. In agriculture, large amounts of P rich fertilisers are regularly applied to farmland to compensate, but this is expensive and can have harmful impacts on the soil structure and composition of microflora [4]. Therefore, alternative, Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00284-020-02238-2) contains supplementary material, which is available to authorized users. * Jiang Tian [email protected] 1
Department of Environment, College of Environment and Resources, Xiangtan University, Xiangtan, People’s Republic of China
environmentally friendly, methods for increasing bioavailable phosphorus (bio-P) in soils are urgently needed for sustainable agriculture [5]. One common approach has been to increase soil acidity, which releases insoluble P and mobilizes P to from organic compounds, thereby increasing bio-P [6]. Microbial communities in soil can also affect soil bioP, direct
Data Loading...
