Isolation of Phosphate-Solubilizing Microorganisms and the Formulation of Biofertilizer for Sustainable Processing of Phosphate Rock

Nipuni Mayadunna; Samantha C Karunarathna; Suhail Asad; Steven L Stephenson; Abdallah M Elgorban; Salim Al-Rejaie; Jaturong Kumla; Neelamanie Yapa; Nakarin Suwannarach

doi:10.3390/life13030782

Isolation of Phosphate-Solubilizing Microorganisms and the Formulation of Biofertilizer for Sustainable Processing of Phosphate Rock

Life (Basel). 2023 Mar 14;13(3):782. doi: 10.3390/life13030782.

Authors

Nipuni Mayadunna^{1

2}, Samantha C Karunarathna^{3

4}, Suhail Asad⁵, Steven L Stephenson⁶, Abdallah M Elgorban⁷, Salim Al-Rejaie⁸, Jaturong Kumla^{1

9}, Neelamanie Yapa², Nakarin Suwannarach^{1

9}

Affiliations

¹ Research Center of Microbial Diversity and Sustainable Utilization, Chiang Mai University, Chiang Mai 50200, Thailand.
² Faculty of Applied Sciences, Rajarata University of Sri Lanka, Mihintale 50300, Sri Lanka.
³ Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing 655011, China.
⁴ National Institute of Fundamental Studies (NIFS), Kandy 20000, Sri Lanka.
⁵ School of Biology and Chemistry, Pu'er University, Pu'er 665000, China.
⁶ Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA.
⁷ Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
⁸ Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.
⁹ Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.

Abstract

As phosphorus (P) bioavailability is limited in arable lands, chemical fertilizers are being used by farmers to increase crop production. Phosphate-solubilizing microorganisms (PSMs) increase the bioavailability of sparingly soluble inorganic and organic soil phosphorus. Therefore, the current study was an effort to evaluate the phosphate-solubilizing efficiency of PSMs using tricalcium phosphate (TCP) and Eppawala rock phosphate (ERP). The efficiency of phosphate solubilization by a series of identified isolates was compared using TCP (5 g L^-1) and ERP (5 g L^-1) as a P source in Pikovskava's broth. Twelve microbial isolates that showed a higher efficiency in phosphate solubilization were selected for the production of the biofertilizer. The isolate F10 in ERP broth was characterized by the highest significant level of available phosphorus (896.98 ± 10.41) mg L^-1, followed by F5 (Aspergillus sp.) in TCP broth 991.43 ± 1.37 mg L^-1. A pot trial was carried out by using Capsicum annuum L. as the test plant in two soil conditions: sterilized soil and non-sterilized soil with six treatments and four replicates. The significantly highest plant height, leaf length, and width were shown by chili plants treated with the formulated biofertilizer. Therefore, the application of native PSMs appeared to be an efficient method of solubilizing sparingly soluble P compounds into plant-available forms.

Keywords: Eppawala rock phosphate; biofertilizer; phosphate solubilization; plant bioavailability.

Grants and funding

This research was partially supported by Chiang Mai University and the National Natural Science Foundation of China (NSFC 32260004). The authors extend their appreciation to the Researchers Supporting Project number (RSP2023R56), King Saud University, Riyadh, Saudi Arabia.