Isolation and Identification of Potential Bio-Inoculants Based on Phosphate Solubilizing Molds From Different Plant Rhizospheres


In crop production, phosphorus (P) is the second most important limiting nutrient. However, due to precipitation reactions with Al3+, Fe3+ in acidic soil, or Ca2+ in alkaline soil, its availability in soil is severely limited. Microbes have recently been proposed as a means of increasing the bioavailability of soil phosphate for plants. The goal of this research was to isolate and identify phosphate solubilizing molds (PSM) from various plant rhizospheres, including gadung (Dioscorea hispida Dennst), maize (Zea mays L.), bamboo (Dendrocalamus asper), pineapple (Ananas comosus L.), and banana (Ananas indica L.). PSM was isolated in vitro and then diluted using the dilution plate technique with Pikovskaya’s solid medium. Five colonies were confirmed as PSM, namely Talaromyces aculeatus, Metarhizium anisopliae, Fusarium proliferatum, Mucor hiemalis, and Aspergillus niger, out of fourteen colonies formed from those rhizospheres. In the PVK solid medium, these isolates were capable of solubilizing insoluble P with a solubility range of 2.05 to 3.03. Talaromyces aculeatus (125.6 mg L-1), Metarhizium anisopliae (80.76 mg L-1) and Fusarium proliferatum (41.59 mg L-1) were the best P solubilizers, followed by Mucor hiemalis (9.51 mg L-1), and Aspergillus niger (7.85 mg L-1), respectively. The bioinoculants Talaromyces aculeatus and Metarhizium anisopliae had the most potential.

Keywords: Dendrocalamus asper, Molds, Phosphate, Rhizosphere, Solubilizer

[1] Saber K, Nahla LD, Chedly A. Effect of P on nodule formation and N fixation in bean. Agronomy for Sustainable Development. 2005;25:389–393.

[2] Khan MS, Zaidi A, Ahemad M, Oves M, Wani PA. Plant growth promotion by phosphate solubilizing fungi—Current perspective. Archives of Agronomy and Soil Science . 2010;56:73–98.

[3] Donahue RLR, Miller RW, Shickluna JC. Soils: An introduction to soils and plant growth. New Delhi: Prentice Hall; 1990.

[4] Lindsay WL, Vlek PLG, Chien SH. Minerals in soil environment. 2nd edition. Dixon
JB, Weed SB, editors. Madison: Soil Science Society of America; 1989.

[5] Gyaneshwar P, Kumar GN, Parekh LJ, Poole PS. Role of soil microorganisms in
improving P nutrition of plants. Plant and Soil. 2022;245:83-93.

[6] Morales A, Alvear M, Valenzuela E, Castillo C, Borie F. Screening, evaluation and
selection of phosphate-solubilising fungi as potential biofertiliser. Journal of Soil
Science and Plant Nutrition. 2011;11:89–103.

[7] Nelofer R, Syed Q, Nadeem M, Bashir F, Mazhar S, Hassan A. Isolation of
phosphorus-solubilizing fungus from soil to supplement biofertilizer. Arabian
Journal for Science and Engineering. 2015;41(6):2131-2138.

[8] Asea PEA, Kucey RMN, Stewart JWB. Inorganic phosphate solubilization by two
penicillium species in solution culture and soil. Soil Biology and Biochemistry.

[9] Illmer PA, Schinner F. Solubilization of inorganic calcium phosphate-solubilization
mechanisms. Soil Biology and Biochemistry. 1992;27:257-236.

[10] Kaur G, Reddy MS. Role of phosphate-solubilizing fungi in sustainable agriculture.
Developments in Fungal Biology and Applied Mycology. 2017:391-412.

[11] Abd-alla MH. Phosphatases and the utilization of organic phosphorus by Rhizobium
leguminosarum biovar viceae. Letters in Applied Microbiology. 1994;18:294-298.

[12] Whitelaw MA. Growth promotion of plants inoculated with phosphate solubilizing
fungi. Advances in agronomy. 2000;69:99–151.

[13] Akintokun AK, Akande GA, Akintokun PO, Popoola TOS, Babalola AO. Solubilization
on insoluble phosphate by organic acid producing fungi isolated from Nigerian soil.
International Journal of Soil Science . 2007;2:301-307.

[14] Kohler J, Caravaca F, Roldan A. An AM fungus and PGPR intensity the adverces
effects of salinity on the stability of rhizosphere soil aggregates of Luctuca sativa.
Soil Biology and Biochemistry. 2010;42:429-434.

[15] Venkateswarlu B, Rao AV, Raina P. Evaluation of phosphorus solubilization by
microorganisms isolated from arid soil. Journal of the Indian Society of Soil Science.

[16] Nahas E. Factors determining rock phosphate solubilization by microorganism
isolated from soil. World Journal of Microbiology and Biotechnology. 1996;12:18–

[17] Marmeisse R, Jargeat P, Wagner F, Gay G, Debaud JC. Isolation and characterization
ofnitrate reductase deficient mutants of the ectomycorrhizal fungus Hebeloma
cylindrosporum. New phytologist. 1998;140:311–318.

[18] Srividya S, Soumya S, Pooja K. Influence of environmental factors and salinity on
phosphate solubilization by a newly isolated Aspergillus niger F7 from agricultural
soil. African Journal of Biotechnology. 2009;8(9):1864-1870.

[19] Xiao C, Chi R, Li X, Xia M, Xia Z. Biosolubilization of rock phosphate by three stresstolerant molds strains. Applied Biochemistry and Biotechnology.2011;165(2):719–727.

[20] Sanjotha P, Mahantesh P, Patil C. Isolation and screening of efficiency of phosphate
solubilizing microbes. International Journal of Microbiology Research. 2011;3:56–58.

[21] Nelson DW, Sommers LE. Methods of soil analysis. D.L. Sparks DL, Page, AL, Helmke,
PA, et al (editors). Madison: Soil Science Society of America, Inc. and American
Society of Agronomy, Inc. ; 1996.

[22] Barnett HL, Hunter BB. Illustrated genera of imperfect fungi. 4th ed. Minnesota: Amer
Phytopathological Society Press; 1998.

[23] Pikovskaya RI. Mobilization of phosphorus in soil in connection with vital activity of
some microbial species. Microbiology. 1948;17:362–370.

[24] Premono EM, Moawad M, Vlek G. Effect of phosphate solubilizing Pseudomonas
putida on thegrowth of maize and its survival in the rhizosphere. Indonesian Journal
of Crop Science. 1996;11:13-23.

[25] Cappucino JG, Sherman N. Microbiology: A laboratory manual. California: The
Benjamin/Cumming Publishing Comp., Inc.; 1987.

[26] Murphy J, Riley JP. A modified single solution method for the determination of
phosphate in natural waters. Analytica Chimica Acta. 1962;27:31-36.

[27] Dharmwal NS, Singh EB, Rai R. Isolation of phosphate solubilizers from different
sources. Current Science. 1989;58:570-571.

[28] Sutton-Grier AE, Wright JP, McGill BM, Richardson C. Environmental conditions
influence the plant functional diversity effect on potential denitrification. PLoS ONE.

[29] Khan AAH, Karuppayil SM. Molds pollution of indoor environments and its
management. Saudi journal of Biological Sciences. 2012;19(4):405-426.

[30] Basu S, Bose C, Ojha N et al. Evolution of bacterial and molds growth media.
Bioinformation. 2015;11(4):182-184.

[31] Yadav K, Singh T. Phosphorus solubilization by microbial isolate from Caci fluvent.
Journal of Indian Society for Sciences. 1991;39:89-93.

[32] Vassilev N, Vassileva M, Nikolaeva I. Simultaneous P-solubilizing and biocontrol
activity of microorganisms: Potentials and future trends. Applied Microbiology and
Biotechnology. 2006;71:137–141.

[33] Uren NC. The rhizosphere. Biochemistry and organic substances at the soil-plant
interface. Pinton R, Varanini Z, Nannipieri P, editors. New York: Marcel Dekker; 2001.

[34] Brady NC, Weil RR. The nature and properties of soils. 13th ed. New Jersey: Prentice
Hall; 1935.

[35] Pandey A, Das N, Kumar B, Rinu K, Trivedi P. Phosphate solubilization by Penicillium
spp. isolated from soil samples of Indian Himalayan region. World Journal of
Microbiology and Biotechnology. 2008;24:97–102.

[36] Yadav J, Verma JP, Tewari KN. Plant growth promoting activities of fungi and their
effect on checkpea plant growth. Asian Journal of Biological Sciences. 2011;4(3):291-

[37] Malviya J, Singh K, Joshi V. Effect of phosphate solubiling fungi on growthand
nutrient uptake of ground nut (Archis hypogaea) plants. Advances in Bioresearch.

[38] Reddy MS, Kumar S, Babita K, Reddy MS. Biosolubilization of poorly soluble
rock phosphates by Aspergillus tubingensis and Aspergillus niger. Bioresource
Technology. 2002;84:187–189.

[39] Banik S, Dey BK. Alluvial soil microorganisms capable of utilizing insoluble aluminium
phosphate as a source of phosphorus. Zentralblatt für Mikrobiologie. 1983;138:437–