Rock phosphate solubilization by abiotic and fungal-produced oxalic acid: reaction parameters and bioleaching potential

TY - JOUR

T1 - Rock phosphate solubilization by abiotic and fungal-produced oxalic acid

T2 - reaction parameters and bioleaching potential

AU - de Oliveira Mendes, Gilberto

AU - Dyer, Thomas

AU - Csetenyi, Laszlo

AU - Gadd , Geoffrey Michael

N1 - Funding Information: GOM was supported by the Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES), grant number 001, the Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG), grant number APQ-01842-17, and the Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq), grant number 401485/2016-1. GMG gratefully acknowledges research support of the Geomicrobiology Group from the Natural Environment Research Council, UK (NE/M010910/1 (TeaSe) and NE/M 011275/1 (COG3)). GOM was supported by the Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES), grant number 001, the Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG), grant number APQ-01842-17, and the Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq), grant number 401485/2016-1. GMG gratefully acknowledges research support of the Geomicrobiology Group from the Natural Environment Research Council, UK (NE/M010910/1 (TeaSe) and NE/M 011275/1 (COG3)). We wish to acknowledge the use of the EPSRC funded Physical Sciences Data-science Service hosted by the University of Southampton and STFC under grant number EP/S020357/1, as well as the American Mineralogist Crystal Structure Database. Publisher Copyright: © 2021 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

PY - 2022/4

Y1 - 2022/4

N2 - Oxalic acid‐producing fungi play an important role in biogeochemical transformations of rocks and minerals and possess biotechnological potential for extraction of valuable elements from primary or waste ores and other solid matrices. This research investigates the extraction of phosphate from rock phosphate (RP) by oxalic acid. Reaction parameters were derived using pure oxalic acid solutions to solubilize RP. It was found that the oxalic acid concentration was the main factor driving reaction kinetics. Excess oxalic acid could retard the reaction due to calcium oxalate encrustation on RP surfaces. However, complete P extraction was reached at stoichiometric proportions of apatite and oxalic acid. This reaction reached completion after 168 h, although most of the P (up to 75%) was released in less than 1 h. Most of the Ca released from the apatite formed sparingly soluble calcium oxalate minerals, with a predominance of whewellite over weddellite. Bioleaching of RP employing biomass‐free spent culture filtrates containing oxalic acid (100 mM) produced by Aspergillus niger extracted ~ 74% of the P contained in the RP. These findings contribute to a better understanding of the reaction between apatite and oxalic acid and provide insights for potential applications of this process for biotechnological production of phosphate fertilizer.

AB - Oxalic acid‐producing fungi play an important role in biogeochemical transformations of rocks and minerals and possess biotechnological potential for extraction of valuable elements from primary or waste ores and other solid matrices. This research investigates the extraction of phosphate from rock phosphate (RP) by oxalic acid. Reaction parameters were derived using pure oxalic acid solutions to solubilize RP. It was found that the oxalic acid concentration was the main factor driving reaction kinetics. Excess oxalic acid could retard the reaction due to calcium oxalate encrustation on RP surfaces. However, complete P extraction was reached at stoichiometric proportions of apatite and oxalic acid. This reaction reached completion after 168 h, although most of the P (up to 75%) was released in less than 1 h. Most of the Ca released from the apatite formed sparingly soluble calcium oxalate minerals, with a predominance of whewellite over weddellite. Bioleaching of RP employing biomass‐free spent culture filtrates containing oxalic acid (100 mM) produced by Aspergillus niger extracted ~ 74% of the P contained in the RP. These findings contribute to a better understanding of the reaction between apatite and oxalic acid and provide insights for potential applications of this process for biotechnological production of phosphate fertilizer.

UR - https://www.scopus.com/pages/publications/85102349542

U2 - 10.1111/1751-7915.13792

DO - 10.1111/1751-7915.13792

M3 - Article

C2 - 33710773

SN - 1751-7915

VL - 15

SP - 1189

EP - 1202

JO - Microbial Biotechnology

JF - Microbial Biotechnology

IS - 4

ER -