Phosphate Solubilization Lab Report

2.4 Mechanism Of Phosphate Solubilization: In contrary to Nitrogen soluble Phosphorous is not supplied to plants by atmosphere . Due to this reason the primary and secondary minerals and/or organic compounds are the source of P to great extent. In soil solution concentration of phosphorous is least as compare to other nutrients and ranges from0.001 to 1mg/ml Brady and Weil (2002 ).There are widely three categories of P compounds in soil: (i) compounds which are inorganic, (ii) organic compounds of the soil humus (iii) organic and inorganic P compounds associated with the cells of living matter( Richardson 1994). The P available to plant out of total soil P is relatively low . To overcome deficiency of P in soil and to give sufficient
may be converted to soluble P.Microorganisms present in soil have mainly been found more potent in making P accessible to plants from both inorganic and organic sources by solubilizing and mineralizing complex P compounds respectively Song et al.(2008). To know how solubilization of insoluble P is caused by microbial populations several workers have documented their findings. Illmer and Schinner 1995 :,Buch et al. 2008 The involvement of Organic acids (OA) secreated by microorganism having low molecular mass has been a well-recognized and widely accepted theory as , various studies have explained their role in the solubilization process by identification and quantification of these OAKhan et al. 2010; Marra et al.( 2012 ) In natural conditions or under in vitro conditions OA produced by many P-solubilizers, for example, bacterial cultures or fungi , chelate mineral ions or lowers the pH to bring P into solution. ((Pradhan and Shukla 2005 Khan et
BR29 (45 days old) cultivated in silt loam soils of Old Brahmaputra Alluvium tract (Sonatola series) in Mymensingh, Bangladesh,and two from seed endophytes and on the basis of their their phenotypic and 16S rRNA genes sequencing identified them as Acinetobacter sp. BR-12, Klebsiella sp. BR-15, Acinetobacter sp. BR-25, Enterobacter sp. BR-26, Microbacterium sp. BRS-1 and Pseudomonas sp. BRS-2.
Kundaetal()isolated 193 PSB from the rhizosphere of chickpea, mustardand wheat grown in different areas of Harayana. On the basis of 20 biochemical test according to Bergey’s Manual of Systematic Bacteriology , placed these isolates tentatively placed into four genera. Eighty seven isolates belonged to the genus Pseudomonas, 27 to Aeromonas, 35 to Klebsiella and 44 to Enterobacter. However, no host specifi city was noticed for PSB.(kundu)
Prabu isolated five PSB from rhizosphere soil samples from four study areas [Ankober and Keyt (yield sustained), Mehalmeda and Molale (yield depleted)] of Ethiopia between May and June 2007. On the basis of , morphological and biochemical characters together with a reference isolate from Jimma (Jim-41) and isolates were found to belong to the genus