Mineral Release Dynamics of Tricalcium Phosphate and Waste Muscovite by Mineral-Solubilizing Rhizobacteria Isolated from Indo-Gangetic Plain of India |
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Authors: | Indra Bahadur Bihari Ram Maurya Madhumonti Saha Ashok Kumar Abhinav Aeron |
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Affiliation: | 1. Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India;2. Department of Agricultural Chemistry and Soil Science, Faculty of Agriculture, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, West Bengal, India;3. Department of Botany, MMV, Banaras Hindu University, Varanasi, Uttar Pradesh, India;4. Division of Biotechnology, College of Environmental and Bioresource Sciences, Chonbuk National University, Iksan-si, Jeollabuk-do (Jeonbuk), South Korea |
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Abstract: | The aim of the present investigation was to evaluate the mineral release abilities of ten rhizobacterial strains isolated from rhizosphere of various crops growing in the Indo-Gangetic Plain (IGP) of India. Their abilities to solubilize inorganic phosphorus (P) and potassium (K) minerals from insoluble tricalcium phosphate (TCP) and waste muscovite (WM) revealed that rhizobacteria significantly solubilized different levels of inorganic P and fixed K, respectively. Some of the rhizobacterial stains have the ability to produce ammonia, indole-3-acetic acid (IAA), and hydrogen cyanide (HCN). The identification based on the 16S rDNA gene sequencing of selected mineral-solubilizing rhizobacteria (MSR) having greater potential to serve as bioagents were identified as Bacillus subtilis (BRHU01, BRHU03, and BHU20), Bacillus tequilensis (BRHU02), Bacillus licheniformis (BRHU04), Bacillus pumilus (BRHU05), Bacillus flexus (BHU02), Brevibacillus formosus (BHU16), Bacillus methylotrophicus (BHU29), and Bacillus amyloliquefaciens (BHU30). Interestingly, inorganic P and K solubilization by these strains belonging to genera Bacillus and Brevibacillus showed significant variations from 0.52 to 14.49 and from 1.62 to 8.60 µg mL?1, respectively. However, generally, pH values of culture media decreased from near neutral (6.43) to acidic (3.83) with increasing incubation period, and this was inversely correlated with quantities of K solubilized by these rhizobacterial strains. Meanwhile, the electrical conductivity (EC) of broth culture increased from 0.09 to 0.23 dS m?1 with increasing incubation period. Principal component analysis (PCA) of the MSR revealed three clusters, which exhibited high variance with respect to nutrient release. Taken together, these results suggest that Bacillus and Brevibacillus sp. identified in this study solubilized varying levels of inorganic P and fixed K from insoluble TCP and WM by acidolysis mechanisms. |
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Keywords: | Indo-Gangetic Plain (IGP) mineral-solubilizing rhizobacteria (MSR) tricalcium phosphate waste muscovite (WM) |
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