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Authors: Govindbhai, Patel Khushbu
Advisor: Jha, Sanjay
Title: Isolation, Screening and Molecular Characterization of Halophilic Phosphate Solubilizing Bacteria From Coastal Area
Publisher: Plant Molecular Biology and Biotechnology, N. M. College of Agriculture
Language: en
Type: Thesis
Pages: 100
Agrotags: null
Keywords: Biotechnology and Molecular Biology
Abstract: Seven bacteria were isolated from the rhizospheric soil collected from the coastal regions of the south gujarat having capacity to solubilize the rock phosphate in tris minimal media containing 500mM NaCI with 100mM buffering. The molecular identification and phylogenetic analysis of seven isolates were carried out by amplification and sequencing of 16s region using pair of primers 27F-1492R. The ability of P solubilization was inversely proportional to pH for each isolates. The isolate Serratia marcescens NAUKPI showed highest reduction in i.e., pH 3.49 ± 0.01 with rock phosphate solubilization up to 738.04 ± 0.0\ IlM followed by Bacillus tequilensis NAUKP2 i.e., 694.87 ± 0.02 IlM with dec erased in pH to 3.62±0.OI in the presence of 500mM NaC!. The solubilization index was calculated at different buffering concentration of tris minimal media. The highest SI was 4.12 ± 0.01 however. as buffering of media increased. SI was lound to be decreased. Organic acid production was analysed by High I'erlormance Liquid Chromatography (HPLC) and isolates were found to produce xylonic acid by using xylose as a carbon source. The highest xylonic acid produced was 37.89±0.01 mM by Serralia marcescens NAUKI'I. The activity of glucose dehydrogenase was also checked and highest GDH activity (0.76±0.02 mM/minlg) was reponed by Serratia marcescens NAUKPI. The halophilic phosphate solubilizing bacterial isolates were also able tolerate the NaCI concentration up to 750mM. However the P solubilization efficiency decreased with the increased in salt concentration. The isolates showed optimum P solubilization in glucose as a sole source of carbon and ammonium nitrate as a sole source of nitrogen. The optimum temperature range was 28°C to 37°C and initial pH was from 7.0 to 8.0 for better P solubilization. However all the isolates were able to tolerate pH 12.0 and temperature up to 60°C. The isolated PSBs also had some plant growth promoting activity. All of them were able to produce the indole acetic acid. The maximum IAA production was 831.4±0.01 flglml by Serratia marcescens NAUKP I. The isolates were also able to produce the siderophore, ACe deaminase and ammonia. They were also able to fix the nitrogen and could tolerate heavy metal at concentration upto 100mM. Moreover, they were also able to produce the enzymes like cellulase, amylase and protease with different efficiency. The experiment was conducted to check P solubilization efficiency of isolates in saline soil for rice and tomato. The growth promoting parameters of the plants were observed after the inoculation of isolates. The Serratia marcescen., NAUKPI showed the improved P content and available P in plant as well as improved the other growth parameters like shoot and root length. shoot and root fresh weight and dry weight, number of lateral roots. chlorophyll content and leaf area of both the crops. It also improved the salt stress mitigation parameters. like increased in K+lNa' ratio. reduced proline and MDA level. The inoculation of four isolates in rice also increased the levels of salicylic acid and antioxidant enzymes as a sign of systemic acquired resistance for bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae. The real time gene expression analysis showed the induction of PAD4 gene, responsible for salicylic acid mediated systemic acquired resistance in rice. The Serratia marcescells NAUKP5 showed ethylene mediated ElL! gene expression in plants defense. Over all in present study Serratia marcescens NAUKPI was most effecient P solubilizer with different plant growth promoting attributes.
Subject: Biotechnology and molecular Biology
Theme: M.Sc. Thesis
These Type: M.Sc
Issue Date: 2016-07
Appears in Collections:Doctoral Theses

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