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2016 - 201722
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Subject: Microbiology × End date: 2017 × Start date: 2015 ×
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Now showing 1 - 9 of 22
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    ThesisItemOpen Access
    Growth promotory effect of drought tolerant bacteria on wheat crop under drought stress
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-07) Gouri, Vinita; Singh, Ajay Veer
    In natural environmental condition plants continuously exposed to various biotic and abiotic factors. Drought is considered as major abiotic stress and adversely affects plant growth and productivity worldwide. Plants under drought stress conditions show reduced root length, shoot length, deficiency of nutrients and increases disease susceptibility and hence decreases economic yield of crop. In this context, present study was carried out with the application of drought tolerant plant growth promoting rhizobacteria (PGPR) in wheat to promote growth and productivity under drought stress conditions. During study, total sixty bacterial isolates were retrieved and revived from departmental culture collection. On the basis of growth present on tryptic soy broth medium supplemented with 6% poly ethylene glycol and 20% NaCl, fourteen bacterial isolates were selected as drought tolerant. These drought tolerant bacterial isolates were further checked for plant growth promoting activities such as siderophore production, zinc solubilization, phosphate solubilization and ACC deaminase activity and ten best potential bacterial isolates were screened for further study. Afterward, screened potential bacterial isolates were selected and characterized on the basis of cell and colony morphology, biochemical characteristics and carbohydrate utilization tests. Now these potential isolates were characterized functionally and tested for plant growth promoting traits such as exopolysaccaride production, ammonia production, indole acetic acid production and hydrogen cyanide production. Furthermore, potential bacterial isolates were evaluated for antibiosis activity against two pathogenic fungi of wheat, four isolates were able to suppress mycelial growth of Fusarium oxysporum and three bacterial isolates were able to suppress mycelial growth of Alternaria spp. However, SRPII7 isolate was effective against both the fungi. Furthermore, an in situ greenhouse pot experiment was designed under drought stress with all ten drought tolerant plant growth promoting isolates with early variety of wheat (Triticum aestivum var. UP-2785). Results of green house pot experiment confirmed that all bacterial isolates were significantly able to improve plant growth and productivity in terms of agronomical parameters such as root length, shoot length, dry weight of plant, spike length, number of grains/spike, 1000 grains weight and % harvest index, while four bacterial isolates i.e. WRPA13, WRPA26, SRA1 and SRK14 prove more potential compare to all other isolates and helps wheat plant to cope up with drought stresses. In vitro and in situ studies depicted the potentiality of four bacterial isolates for their promising plant growth promoting activity under drought stress. In respect to said results, present study concluded that these four potential bacterial isolates i.e. WRPA13, WRPA26, SRA1 and SRK14 can be employed as bioinoculant/biofertilizer to improve drought tolerance and nutrient enhancement in wheat crop for sustainable agriculture.
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    ThesisItemOpen Access
    Mycoremediation of toxic synthetic industrial dyes using lignolytic fungal isolates
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2016-07) Rana, Babita; Tewari, Lakshmi
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    ThesisItemOpen Access
    Assessment of Pseudomonas fluorescens AS15 inoculation on growth and establishment of Dalbergia sissoo nursery
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2016-06) Dasila, Hemant; Sahgal, Manvika
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    ThesisItemOpen Access
    Zinc and iron biofortification strategies through plant growth promoting Rhizobacteria in wheat
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2016-08) Rawat, Saloni; Singh, Ajay Veer
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    ThesisItemOpen Access
    Phosphate solubilization by indigenous soil microbiodata under stress conditions
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2016-08) Bisht, Seema; Tewari, Lakshmi
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    ThesisItemOpen Access
    Behaviour of TiO2 nanoparticles on plant growth promotory Rhizobacteria and soil properties of maize rhizosphere
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2016-06) Hema Kumari; Sharma, Anita
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    ThesisItemOpen Access
    Comparative phylogenetic analysis of chickpea nodulating rhizobia from Central India and Terai region of Western Himalayas
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-07) Maithani, Damini; Sahgal, Manvika
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    ThesisItemOpen Access
    Effect of two nanocompounds on fenugreek vigour and soil health under the influence of plant growth promoting rhizobacteria
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-06) Swati Kumari; Sharma, Anita
    Nanotechnology has been designated as one of the most potential field for research that permits researchers to control the materials at molecular, macromolecular and atomic level. The characteristics of nanomaterials and their utility differ notably from the original compound at macroscopic scale. Effect of two nanocompounds (Nanozeolite and Nanochitosan) on germination and vigour of fenugreek and soil health under the influence of Plant Growth Promoting Rhizobacteria was studied in a pot experiment. Two bacterial isolates (PS2 and PS10) were selected on the basis of their plant growth promoting properties. PS2 and PS10 were characterized on the basis of molecular characters and found to have homology with Bacillus sp. on the basis of BLAST and were allotted with accession number as KX650178 and KX650179, respectively. PS2 and PS10 produced 44.96 and 23.16 % Siderophore unit, 13.84 µg/ml and 9.29 µg/ml IAA and solubilized 2.34 µg/ml P and 2.22 µg/ml P, respectively. Enhanced average plant height, no. of leaves, leaf area and fresh weight (1.5 - 2.0 folds) over control was observed in the presence of nanocompounds + bacterial treatments. Average total chlorophyll (3.27 mg/g) and catalase activity (23.84 U/g tissue) was maximum for PS2+Nz treatment. Total soluble leaf protein was maximum (295.37mg/g fresh weight) in the PS2+Nch treatment, which was 10% more than control. Total sugar was maximum (6.14 µg/mg dry wt.) in PS10+Nz treatment and was about 13% more than control. After 45 days of pot experiment, maximum fluorescein diacetate hydrolysis activity (2.5 fold increase) was observed in the soil under treatment of PS10+Nz. Maximum alkaline phosphatase activity i.e., 41.35 µg/g/h (11% increase) was reported in the PS10+Nz treatment whereas maximum dehydrogenase activity i.e., 3.65 µg/5g/8h (2.2 fold increase) was observed in the PS10 treatment. It can be concluded from our findings that application of nanocompounds along with bacterial treatments improved plant-bacterial interaction, promoted plant parameters, increased microbial diversity and increased the level of soil health indicator enzymes.
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    ThesisItemOpen Access
    Development of Microbial Consortia for Bioremediation of Toxic Synthetic Industrial Dyes
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-06) Martoliya, Yogita; Tewari, Lakshmi
    For rapid and cost effective biological removal of synthetic industrial dyes (congo red, direct green, direct black and brilliant green), twenty eight microbial cultures were isolated from different sources. Seventeen bacterial isolates, seven fungal isolates, three microalgae and one cyanobacterium were screened qualitatively for their in vitro dye decolorization efficiency. Selected isolates were then evaluated spectrophotometrically for quantification of dye decolorization. The bacterial isolate PMB1, fungal isolates PMF2, WFPN1 and T. harzianum showed 100% decolorization potential for azo dyes in 5-6 d, while the three microalgae (PASM, PHSM and PRSM) isolates and the cyanobacteria (Synechococcus sp.) showed 100% decolorization for brilliant green dye in 4 d. These selected isolates were then checked for extracellular enzyme activities (laccase, lignin peroxidase (LiP), manganese peroxidase (MnP) and azoreductase) in culture filtrates. Maximum enzyme activities by the selected fungal isolates PMF2 and WFPN1 were recorded for laccase enzyme followed by azoreductase enzyme, while no MnP and LiP activities were observed. The fungal isolate PMF2 showed maximum laccase activity (101.74 U/mL) followed by WFPN1 (64 U/mL) in presence of direct black dye, while for congo red dye, maximum laccase activity was recorded for WFPN1 (30 U/mL) followed by PMF2 (25.61 U/mL). In the absence of dye the maximum laccase activity was recorded in WFPN1 (25.96 U/mL) followed by PMF2 (19.45 U/mL). Maximum azoreductase activity was observed for the fungal isolate WFPN1 (20 U/mL and 14.91 U/mL) for direct black and congo red dye respectively. For increasing dye decolorization efficiency, 22 microbial consortia were developed for direct black dye using fungal and bacterial isolates and 15 consortia for brilliant green dye by using microalgae, Cyanobacteria and fungal isolates. Some of the consortia were found better as compared to their mono-cultures for decolorization of direct black and brilliant green dyes showing 100% removal of direct black and brilliant green dyes in 4 d and 2 d respectively. Zymogram analysis by activity staining through native PAGE indicated induction of certain extracellular laccase isoforms (~50 kDa - ~75 kDa) in the presence of azo dyes. Spectral analysis (UV-Visible spectroscopy and FTIR) also confirmed degradation / removal of these dye by the potential isolates. The isolate WFPN1 showing maximum dye decolorization and enzyme production was found as most potential strain and identified as Ganoderma lucidum based on 18S r-RNA gene sequence analysis.