Solubilization of iron and calcium phosphates by soil fungi isolated from coffee plantations

• Published in: Archiv für Acker- und Pflanzenbau und Bodenkunde Vol. 59; no. 2; pp. 185 - 196
• Main Authors: Posada, Raúl Hernando, Heredia-Abarca, Gabriela, Sieverding, Ewald, Sánchez de Prager, Marina
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 01.02.2013; Taylor & Francis Ltd
• Subjects: agar; Cylindrocarpon; fungal biotechnology; Fusarium; iron; microbial biomass; Neonectria; Paecilomyces; Paecilomyces marquandii; Penicillium; Penicillium janthinellum; plantations; soil fungi; solubilization; tricalcium phosphate; tropical soils; Colombia; Mexico
• ISSN: 1476-3567; 0365-0340; 1476-3567
• DOI: 10.1080/03650340.2011.610030

Almost 900 fungal isolates were obtained from eight coffee plantations in Colombia and Mexico. Of these, 76 isolates showed activity to solubilize Ca₃(PO₄)₂ (PCa) and FePO₄·H₂O (PFe), which had been added to agar in a plate test. Generally, PCa was better solubilized than PFe. Colombian isolates were generally somewhat less effective than Mexican isolates. The two most effective isolates from each country with apparent highest PFe, solubilization potential were selected and cultivated in liquid medium containing PFe, which is more prevalent in tropical soils. The pH value, solubilized P in the medium and P uptake in fungal biomass were determined. After 24 days, Cylindrocarpon didymum and C. obtusisporum (both from Colombia) had solubilized 9.9 and 6.4 mg PO₄³⁻-P L⁻¹ and took up 8.6 and 11.6 mg P in biomass. Penicillium janthinellum and Paecilomyces marquandii (both from Mexico) solubilized 7.0 and 1.9 mg PO₄³⁻-P L⁻¹ and took up 11.3 and 17.3 mg P in biomass. The potential practical use of the four fungal isolates for different strategies in making more P available for coffee growth is discussed.